asset management plan 2012 - 2022

Asset Management Plan2012 - 2022

West Coast’s Locally Owned Electricity Distributor

Asset Management PlanA 10 Year Management Plan for Westpower’s Electricity NetworkFrom 1 April 2012 to 31 March 2022

Westpower LimitedPO Box 375GreymouthWeb site www.westpower.co.nzPhone + 64 3 768 9300Fax + 64 3 768 27661st published March 1993

© Copyright: Westpower Ltd. 2012

This document is entitled to the full protection given by the Copyright Act 1994 to the holdersof the copyright. Reproduction of any substantial passage from this document is a breach of the copyright. This copyright extends to all forms of photocopying and any storing of material in any kind of informationretrieval system. All applications for reproduction in any form should be made to Westpower Ltd.

Plan compiled by: Asset Management Division

This issue approved by Westpower Board of Directors

March 2012

CONTENTS 1

Liability DisclaimerThisAssetManagementPlan(AMP)hasbeenpreparedandpubliclydisclosedinaccordancewiththerequirementsoftheElectricityInformationDisclosureRequirements2004andtheamendments2006.

SomeoftheinformationandstatementscontainedintheAMParecomprisedof,orarebasedon,assumptions,estimates,forecasts,predictionsandprojectionsmadebyWestpowerLimited(Westpower).Inaddition,someoftheinformationandstatementsintheAMParebasedonactionsthatWestpowercurrentlyintendstotakeinthefuture.Circumstanceswillchange,assumptionsandestimatesmayprovetobewrong,eventsmaynotoccurasforecasted,predictedorprojected,andWestpowermayatalaterdatedecidetotakedifferentactionstothoseitcurrentlyintendstotake.

Exceptforanystatutoryliabilitywhichcannotbeexcluded,Westpowerwillnotbeliable,whetherincontract,tort(includingnegligence),equityorotherwise,tocompensateorindemnifyanypersonforanyloss,injuryordamagearisingdirectlyorindirectlyfromanypersonusingorrelyingonanycontentoftheAMP.

When considering any content of the AMP, persons should take appropriate expert advice in relation to their owncircumstancesandmustrelysolelyontheirownjudgementandexpertadviceobtained.

2 WESTPOWERASSETMANAGEMENTPLAN2012-2022

Contents

1.0 EXECUTIVE SUMMARY 41.1 PurposeofthePlan 4

1.2 ImprovementstotheAMP 4

1.3 Westpower’sNetwork 5

1.4 Westpower’sAssetManagement Process 5

1.5 AssetsCovered 9

1.6 AssetManagementPolicy 9

1.7 LevelsofService 11

1.8 ReliabilityTrends 11

1.9 SecurityofSupply 12

1.10 NetworkDevelopment 13

1.11 LifecycleManagementPlan 14

1.12 FinancialSummary 15

1.13 AssetManagementPractices 16

1.14 RiskManagement 18

1.15 PlanOutcomes 20

2.0 INTRODUCTION 21

2.1 Background 21

2.2 AssetOwnershipJustification 37

2.3 JustificationofAssets 37

2.4 AssetManagementDrivers 44

2.5 AssetManagementLinkage withWestpowerPerformance 45

2.6 PlanStructureandApproach 46

2.7 CoreandAdvancedAsset Management 46

2.8 AssetManagementSystems andProcesses 47

3.0 ASSETS COVERED 583.1 AssetCondition 58

3.2 TranspowerGXPs 61

3.3 SubtransmissionAssets 61

3.4 DistributionAssets 69

3.5 ReticulationAssets 75

3.6 Services 78

3.7 ZoneSubstations 79

3.8 DistributionSubstations 87

3.9 MVSwitchgear 92

3.10 SCADA,CommunicationsandProtection95

3.11 RippleInjectionPlants 98

3.12 OptimisedAssets 99

3.13 Generation 100

3.14 LoadandCustomerCharacteristics byGXP 100

3.15 VoltageSupportSystems 102

3.16 WestpowerMobileSubstation 103

3.17 SubstationBuildings 104

4.0 LEVELS OF SERVICE 1064.1 Introduction 106

4.2 Customer-OrientatedPerformance Targets 106

4.3 OtherTargets 114

4.4 JustificationforTargets 115

4.5 StakeholderNeeds 118

5.0 NETWORK DEVELOPMENT 1195.1 Introduction 119

5.2 PlanningCriteriaandAssumptions 119

5.3 PrioritisingNetworkDevelopment 123

5.4 LoadForecasting 125

5.5 DistributedGeneration 136

5.6 Non-NetworkOptions 140

5.7 NetworkDevelopmentOptions 141

5.8 NetworkDevelopmentProgrammes 144

CONTENTS 3

5.9 OverallWorkPlan 177

5.10 SubtransmissionAssets 181

5.11 DistributionAssets 186

5.12 ReticulationAssets 190

5.13 Services 194

5.14 Zonesubstations 195

5.15 DistributionSubstations 204

5.16 MVSwitchgear 206

5.17 SCADA,CommunicationsandProtection210

5.18 DistributionTransformers 214

5.19 Other 216

6.0 ASSET LIFECYCLE MANAGEMENT 2186.1 Introduction 218

6.2 MaintenanceandOperation 218

6.3 Disposal 221

6.4 MajorMaintenanceProjects 222

7.0 FINANCIAL SUMMARY 2287.1 FinancialForecasts 228

7.2 AssumptionsandSensitivityAnalysis 231

7.3 ActualDeviationsfromPreviousAMPs 234

8.0 ASSET MANAGEMENT PRACTICES 2418.1 Introduction 241

8.2 AssetManagementPolicy 242

8.3 Rationalisationofresponsibilities andprocedures 244

8.4 Networkservicesoperationalsupport 244

8.5 Informationsystemsdevelopment 244

8.6 Specifications,proceduresandmanuals 244

8.7 Deregulation/CompliancewithMEDand CommerceCommissionRequirements 245

8.8 AssetRenewalPolicy 245

8.9 CAPEXAnalysis 245

8.10 DistributedGeneration 246

8.11 AssetManagementSystem ImprovementProcess 246

8.12 DetailedFindings 250

8.13 AssetandWorksManagement SystemDevelopment 295

9.0 RISK MANAGEMENT PLAN 2989.1 RiskManagementPlanningFramework 298

9.2 RiskPlanningMethodology 298

9.3 FailureModeandEffects:Criticality Analysis 303

9.4 Safety 303

9.5 Environmental 304

9.6 KeyRisksIdentified 304

9.7 GeneralMitigationMeasures 306

9.8 WestCoastEngineeringLifelinesPlan: Survey2004/2005 306

9.9 TransmissionLines 307

9.10 Communications 309

9.11 DisasterRecovery 309

AppendixA: MainentanceActivity Definitions 311

AppendixB: CommerceCommisionCross ReferenceTable 315

AppendixC: NetworkReliabilitybyZone SubstationandFeeder 318

AppendixD: ExpenditureForecastand Reconciliation 322

AppendixE: GlossaryofTerms 323


1.0 EXECUTIVE SUMMARY

1.1 Purpose of the Plan

TheAssetManagementPlan(AMP)isafoundationdocumentthatdrivestheplanningforallworkundertakenonWestpower’sassets.Inparticular,itisakeyelementofWestpower’sassetmanagementframeworkandisusedtodemonstratecompliancewithgoodassetmanagementpracticeintermsoftheinternationalPAS-55standard.

Eachyear,acomprehensiveupdateoftheplaniscompleted,includingnetworkchangesthathavetakenplace.Furthermore,theresultsofaformal,externalpeerreviewprocessaretakenintoaccounttoensurethatthisplanmeetscurrentdisclosurerequirementsintermsoftheElectricityInformationDisclosureRequirements2008andiscontinuallyimproved,intermsofbothcontentandlayout.

1.1.1 PeriodCovered

ThisparticularplanwascompletedinJanuary2012andcoversaplanningperiodfrom1April2012throughto31March2022.Themainfocusisplacedonthenextthreeyears,withupdatesbeingcompletedannually.

This Executive Summary is prepared for peoplewhomay not be involvedwithin the business of electricitydistributionnetworksandassociatedservices,butwhounderstandandhaveaninterestinefficientmanagement.

ThisplanwasapprovedbyWestpower’sBoardofDirectorsonthe1stMarch2012.

1.1.2 ObjectiveoftheAMP

ThedefinedobjectiveoftheAMPis:

“Toprovideasystematicapproachtotheplanningofprogrammeswhichareintendedtoensurethattheconditionandperformanceof infrastructureassetsarebeingefficientlymaintainedor improvedtosatisfystakeholdersrequirements.”

1.1.3 CompanyMissionandStatementofCorporateIntent

Westpower’smissionistobe:

“AWest Coast Company operating successful businesses which provide first class electrical and technologysolutions,whereverourcustomerstakeus.”

Westpower’svisionistobe:

“Recognisedforexcellenceinalllinksoftheelectricityvaluechain.”

Salient statements fromtheStatementofCorporate Intent (SCI) that relate tomanagementofWestpower’sassetsinclude:

• TocontinuetoprovideWestCoastcommunitieswithasafe,secure,sustainableandcost-effectiveelectricitydistributionnetwork;

• ToensureobligationsundertheEnergyCompaniesAct1992,theElectricityAct1992,theElectricityIndustryReformAct1998andtheirvariousamendmentsandregulationsaremet;

• To continue to lobby on behalf of West Coast consumers to ensure that a reliabletransmissionnetworkismaintainedintotheWestCoast.

1.2 Improvements to the AMP

Westpower’sAMPfortheten-yearperiod1April2012through31March2022hasbeenthoroughlyreviewedandcomparedagainstotherElectricityLinesBusiness(ELB)plansandindustrycommentsandreports.

EXECUTIVESUMMARY 5

1.3 Westpower’s Network

This AMP includes Westpower’s assets that transport electricity (owned by the electricity retailers) fromTranspower’s sevenGrid Exit Points (GXPs) to over 13,000 electricity consumers on theWest Coast ofNewZealand’sSouthIsland.

TheWestpowernetworkconsistsof110kV,66kVand33kVsubtransmissionnetworkssupplying110/33/11kVsubstationsatReeftonandLogburnRoad,66/33/11kVsubstationsatDobsonandHokitika,66/11kVsubstationsatGreymouthandKumara,and33/11kVsubstationsatGlobe,Blackwater,PikeRiver,Ngahere,Arnold,Rapahoe,Ross,Waitaha,Harihari,Whataroa,Wahapo,FranzJosefandFoxGlacier.

Transpower’s seven GXPs supplyingWestpower’s networks are Reefton and Atarau at 110 kV; Greymouth,KumaraandHokitikaat66kV;Dobsonat33kVandOtiraat11kV.

Westpowerhasnetworkassetsthroughoutthe18,017squarekilometresoftheWestCoastfromLyell intheNorthtoParingainSouthWestlandwithatotalofsome40,000assetsin76classifications.

Thedistributionsystemcomprises2151circuitkilometresofhigh-voltageAlternatingCurrent(AC)distributionlines,21zonesubstationsandswitchyardsstrategicallylocatedthroughoutthenetwork(which,inturn,providean11kVsupplyfordistributionto2308distributionsubstations),onecontrolroomandatelecommunicationsnetwork.Figure1.1showsamapoftheWestpowernetworkareainrelationtotheotherSouthIslandELBs.Table1.2showsthenetworksummaryasat31March2012.

Westpower’sdistributionlinesconsistofvaryinglinecapacities,whicharedependentuponlocaldemandsandgeographicalconsiderations.Operatingvoltagesinclude110kV,66kV,33kVand11kV.Theselinesinvolvealargepopulationofpoles,transformers,disconnectersandotherassetsofvaryingtypesthatareessentialtothedistributionofelectricity.Figure1.4showsadiagramofWestpower’snetwork.

Both themanagement and themaintenance of the network is carried out by ElectroNet Services (based inGreymouth)asthepreferredcontractorandawhollyownedsubsidiaryofWestpower.TheAssetManagementDivisioncarriesoutallmanagementoftheassetsandrepresentstheassetowner.TheOperationsDivisioniscontracted toundertake the inspection, servicingand testing,alongwith fault calloutand fault repairwork.Majorlinereplacement,enhancementordevelopmentprojectsarealsoissuedtoElectroNetServicesasdesignbuildcontracts.Figure1.3showsaphotooftheirheadofficeinTainuiStinGreymouth.

1.4 Westpower’s Asset Management Process

Figure1.5illustratesWestpower’sassetmanagementprocess.TheassetmanagementpolicyprovidesthekeylinkagebetweenWestpower’sstrategicbusinessplanandtheassetmanagementprocess.ThisisconsistentwiththeSCIandisapprovedbytheBoardofDirectors.


Table 1.2 - Network Summary

Description Quantity

ConsumerConnections 13,032

NetworkMaximumDemand(MW) 50.52

NetworkDeliveries(GWh) *N/A

AnnualLoadFactor(%) 31

Lines&Cables(circuitkm) 2151

ZoneSubstations 21

DistributionSubstations 2347

NetworkOptimisedDepreciatedRe-placementCost($m) *N/A

Figure1.3-Westpower’sGreymouthHeadOffice

*Thesefiguresarenotavailabletilltheendofthefinancialyear.

Figure1.1-MapofWestpower’sNetwork

EXECUTIVESUMMARY 7

Figure1.4-Westpower’sNetworkDiagram

33kV11kV

PIKE

11kV

LOGBURN

AtarauSwitchingStation(ATU110)

11kV

33kV

11kV

BLACKWATER

66kV

DOBSON(ATU110)

NGAHERE

33kV

REEFTON(RFN110)

11kV

GLOBE

11kV

11kV

ARNOLD

G 3MW

3.3kV

66kV

11kV

GREYMOUTH(GYM066)

6.6kV

66kV

11kVOTIRA (OTI011)

11kV

33kV

66kV

HOKITIKA(HKK066)

ROSS

11kV

11kV

WAITAHA

HARIHARI

11kV

WHATAROA

WAHAPO

11kV

11kV

G3MW

FRANZJOSEF

11kV

11kV

FOXGLACIER

110kV

66kV

33kV

11kV

6.6kV

3.3kV

LEGEND

GXPs

TranspowerOwned

(HKK066)

TwoMileRoad

Kawhaka

Coleridge66kV

ArthursPass66kV

Ina

ng

ah

ua

11

0k

V

TRANSPOWER

TR

AN

SP

OW

ER

66kV

KUMARA(KUM066) 10MW

11kV

G

SwitchingStation

RAPAHOE

11kV


Figure1.5-Westpower’sAssetManagementProcessFlowDiagram

EXECUTIVESUMMARY 9

1.5 Assets Covered

Westpowerownselectricity reticulationassets thatareused toprovidedistributionandconnectionservicestoelectricityretailersandgenerators.TheseassetsgenerallycompriseequipmentthatiscommontoallNewZealand ELBs and,wherever possible, industry standard assets have been employed. In particular, theAMPcoverstheelectricityandassociatedsystemsownedbyWestpower,comprising:

• Subtransmissionassets–electriclinesandcables,includingassociatedeasementsandaccesswaysoperatingatvoltagesof33kVandhigher;

• Distributionassets–electriclinesandcables,includingassociatedeasementsandaccesswaysoperatingatavoltageof11kV;

• Reticulationassets–400Velectriclinesandcables,includingassociatedeasementsandaccessways;

• Services – connection assets at any voltage ownedbyWestpower for the purpose of supplying a singlecustomer(notincludingthelineonthecustomer’spremises).

• Zonesubstations–high-voltagesubstationsconnectedtothesubtransmissionnetwork.This includesallplant and equipment within the substations such as transformers, switchgear, structures and buswork,Supervisory Control and Data Acquisition (SCADA), protection and metering equipment, together withstationlandandbuildings;

• Distribution substations – substations connected to the distribution network. This includes plant andequipment within the substations such as fuses, platforms, lightning arrestors and maximum demandindicators,togetherwithlandandfibreglasscoversbutexcludingtransformers;

• MV switchgear – circuit breakers, reclosers, sectionalisers, regulators and disconnecters used in thedistributionandsubtransmissionsystems;

• SCADA,communicationsandprotectionequipment–SCADA,communicationsandprotectionequipment,and associated facilities not installed at zone substations. This includes control room equipment, radiorepeatersandfibre-opticsystemsinstalled,ownedandmaintainedbyWestpower;

• Distribution transformers–standard transformersused indistributionsubstations ranging from5kVAto1000kVAandgenerallyhavingaprimaryvoltageof11kV;

• Ripplecontrol–rippleinjectionequipment;

• Embeddedgeneration–generationunitsconnectedtoWestpower’snetworkbutnotnecessarilyownedbyWestpower;

• Capacitorunits–forvoltagesupport;

• Mobilesubstation–allowsimprovedmaintenanceaccesstoexistingsubstationsandforemergencyuseincaseofsubstationfailure;

• Buildings–substationbuildingswithintheWestpowernetwork.

WestpowerownsassetsthroughoutthelengthoftheWestCoastoftheSouthIsland,anditsareaextendsaboutasfarasthedistancefromChristchurchtoDunedin.

1.6 Asset Management Policy

Weare committed tomaximising our shareholders’ investments in a legally and environmentally compliantandsustainablemanner,withoutcompromisingthehealthandsafetyofouremployeesandconsumers,orthepublic.Weshallachievethisbyadoptingthefollowingpolicystatement.

Safety

• Safety-Safetyisofparamountimportanceineverythingwedoandwillnotbecompromisedforcost,timeoranyotherreason.


Reliability

• Reliability of supply - Through continued investment in relevant technology and system configuration,reliabilitymustmeetapprovedtargetsatalltimes.

• Qualityofsupply-Qualityofsupply,commensuratewiththeloadtypeandcriticality,mustmeetWestpower’sstandardsRemedialactionwillbetakenwherestandardsarenotmet.

Security

• Securityofsupply–Thedesiredlevelofsecurityisdefinedbygoodindustrypractices,andlong-termplansmustbedevelopedtoachievetherequiredsecurity.

• Transpower–EveryeffortmustbemadetofocusTranspoweronsecurityofsupplyfortheWestCoast.

Sustainability

• Maintainservicepotential-ThefutureofWestpower’sbusinessiswhollydependentontheabilityofthenetworktocontinuetoprovideservicesfortheforeseeablefuture.Everyeffortmustbemadetomaintaintheongoingservicepotentialofthenetworkwhereappropriate.

• Supporting economic growth -We recognise the electricity infrastructure as a key enabler of economicgrowthandwillworkwithcurrentandfuturedeveloperstoprovideelectricitywiththecapacity,securityandqualityrequiredtosupporttheirbusiness.

• Continual improvement–Theassetmanagementsystemwillbereviewedonanannualbasisandwhereweaknessisfound,improvementswillbemade.CompliancewithPAS-55:2008shallbesupported.

• Strategicandlong-termplanning–Ourinfrastructurebusinessinvolveslong-terminvestmentsandwewillensureourdecisionsalignwithandsupporttheorganisation’sstrategicplan.

• New investment – Any new investmentmustmeet the shareholders’ expectations and approval wherenecessary.

• Communication – The requirements of the asset management system must be communicated to allstakeholderstoenablethemtobeawareoftheirobligationsandtoensuretheirexpectationsareconsideredinallaspectsofplanning.

Cost-efficiency

• Cost-efficiency-Allprojectsmustcompeteforfinancialresources.Prudentassetstewardshiprequirescarefulbudgetingandrobustfinancialreviewprocessestoensuremaximumcostefficiencyisassured.Opportunitiesfor improved productivity through training, technology, process improvements or othermeans shall beconstantlypursued.

• Energy-efficiency–Energy-efficiencyisencouragedinallareasofWestpower’sactivitiesandwillcontinuetobeakeyoutcomefromthedesignprocess.Whereopportunitiesexisttoenhanceenergy-efficiencyforexistingassets,theseareactivelypursuedandimplementedwheretechnicallyandeconomicallyfeasible.

• Technology-Technologyisseenasakeyenablerinprovidingimprovedserviceandvaluetoourconsumers.Wewillcontinuetokeepabreastofdevelopmentsinthefieldofnewandemergingtechnology,andapplythesetoWestpower’snetworkwhereappropriate.

• Fairpricing–Thepriceofelectricitytoconsumersmustbetransparentandfairtoallusersoftheassets.

• Capitalcontributions–Anyexpensefornetworkextensionstosupplynewloadswillbemetbyaconsumercontributiontowardsthecostsinvolved.

Environmental Impact

• Environmentalimpact-Westpowerisenvironmentallyresponsibleandcarefullyconsiderstheenvironmentalimpactofanyof itsactions. Furthermore,thecompanyworkshardtomitigateanynegativeeffectsandprovideanetenvironmentalbenefitwherethisispractical.

EXECUTIVESUMMARY 11

Risk Management

• Risk Management –Westpower adopts the AS/NZS ISO 31000:2009 standard in its approach to riskmanagementandhasagroupriskmanagementplanthat includesbusiness impactanalysisandbusinesscontinuityplanning. Theassetmanagement systemwill developa riskmanagementplan that is directlyrelatedtoWestpower’sdistributionassets.

1.7 Levels of Service

Westpower’sprimarybusinessistoprovideasecure,high-qualityelectricitysupplytoitsconsumersinacost-effectivemanner and to ensure that stakeholder’s interests aremet. To achieve theseobjectives,we are incontinuedconsultationwithconsumerstoensurethattheirrequirementsareconsidered.

Webelieve this consultationhas resulted ina strong focusoncontinuityof supply,which is reflected in thecomparisonofinternationalreliabilitymeasures(e.g.theSystemAverageInterruptionDurationIndexorSAIDI,withotherELBs).

Table1.6providesanoverviewofourperformanceinthekeyareasofservice.MoredetailedversionofthistableisshowninSection4(asTables4.3and4.4),whichbreakdowntheSAIDIandSAIFI(SystemAverageInterruptionFrequencyIndex)figuresintotheurban,ruralandremoteruralcategories.

ThetargetsshowninTable1.6arethesameasthosesetinthe2010-2011AMPandarebasedonnormaliseddatathatexcludeextremeevents,accordingtotheCommerceCommission’sdefinition.ThisapproachbetterrepresentstheunderlyingperformanceofthenetworkandprovidesforamoremeaningfulcomparisonwithotherELBs.

1.8 Reliability Trends

TheharshgeographicnatureandextremeweatherconditionsexperiencedontheWestCoastcancontributeto unpredictable supply outages.With this in mind, every effort has beenmade to mitigate these naturalenvironmental factors bymeans of protectiondevices such as automatic reclosers on distribution lines andlightningarrestorsonalldistributionsubstations.

Historicalreliabilitystatisticsindicatethatarelativelyhighnumberoffaultsareincurredduetotreestrikes.Forthisreason,anongoingandcomprehensivetree-trimmingprogrammehasbeeninstitutedtoreducethenumberofoutagesfromthissource.Figure1.7showsthereliabilitytrendsbasedon“tree-related”issuesonlyandtheimpactoftheprogrammesince2005-06.

Toassist inpreventingoutagesduringplannedmaintenance, contractorsareencouraged toemploy live linetechniqueswherepracticable.

Table 1.6 - Service Level Performance Summary

Service Criterion Quality Group Target Level of

Service Level of Service Indicator Measurement Process

Reliability Faults/100kmofcct 5.76 5.35 Figuresfortotalvaluesdis-closedinaccordancewiththeElectricityInformationDisclosureRequirements

2008

Westpowernetworkfaults,loggedasoutages

occur

TotalSAIDI 175 188

TotalSAIFI 1.99 2.62

TotalCAIDI 88 72

Efficiency CapacityUtilisation 30 31 %used Maximumdemand/transformercapacity


Figure1.8belowdepictsWestpower’sreliabilitytrendoverthelastfiveyearsexcludingMajorEventDays(MEDs)asdefinedbytheCommerceCommission.

1.9 Security of Supply

Ingeneral,Westpower’ssecuritylevelsmeetacceptedguidelinesforloadsofthissizeandtype.

Forloadsof10MWandabove,ann-1securitylevelismaintained,sothatsupplycanbemaintainedintheeventofanysinglecomponentfailure.Forsmallloadsoflessthan1MW,nobackupisspecificallyprovided,exceptwherethereareconvenientlyavailablebackfeedsfortying11kVfeederstogether.

SupplytothecentralbusinessdistrictsofHokitikaandGreymouthissecure,withadequateredundancybuiltin,includingdiversecableroutes.

Figure1.7-NumberofVegetation-RelatedFaults

0

5

10

15

20

25

30

35

40

2006-07 2007-08 2008-09 2009-10 2010-11

No

. o

f Tree

Re

late

d F

au

lts

Year

Figure1.8-Westpower’sFour-YearReliabilityTrend(ExcludingMED’s)

0.0000

0.5000

1.0000

1.5000

2.0000

2.5000

3.0000

3.5000

0.00

50.00

100.00

150.00

200.00

250.00

2006-07 2007-08 2008-09 2009-10 2010-11

Min

ute

s L

os

t

Year

SAIDI

SAIFI

EXECUTIVESUMMARY 13

ThemajorrisktothesecurityofsupplytotheWestCoastlieswiththeTranspowernetwork.Therearetwolong,exposedtransmissionfeedsintotheWestCoastfromInangahuatothenorthviaReeftonandfromColeridgetotheeastviaOtira(seeFigure1.9),supportedbyTrustPowergenerationatpeaktimes.

Local generation has greatly reduced the riskof major system outages when a Transpowerfault occurs. Furthermore, the ability to use theWestpowermobilesubstationforplannedoutagesoramajorplantfaultprovidesadditionalsecurity.

TheTranspowerWestCoastGridUpgradeProject(WCGUP), which was approved by the ElectricityCommission* in 2008, will provide for additionaltransmission security to the West Coast throughtheconstructionofasecond110kVtransmissionline fromReefton toDobsonand installationofa14MvarcapacitorbankatHokitika.Thecapacitorbank was commissioned in May 2010, providingmuchneededinterimvoltagesupporttotheWestCoast. The second 110 kV transmission line fromReefton to Dobson and its associated equipmentwas commissioned in late 2011, significantlyimprovingthesecurityofsupplyinthearea.

Westpower losses, which stand at approximately5% of energy delivered, are managed throughoptimising conductors and transformers inaccordancewithgoodindustrydesignprinciples.

1.10 Network Development

AlthoughthekeydriverfordevelopmentoftheWestpowernetworkisdemand,systemsecurityisalsoamajorfactor.TheWestCoastareaiscurrentlyexperiencingrelativelyflateconomicgrowthfollowingabuoyantperiodoverrecentyears.ThePikeRiverminedisasterthatoccurredon19November2010hashadasignificantimpactonloadgrowthforecasts,andforthepurposesofthisplan,itisassumedthattheminewillnotrestartwithinthenexttwoyears.Notwithstandingthisimpact,underlyinggrowthinotherindustriescontinuestounderpineconomicperformanceinthearea.

To identify the future impact of this driver, load forecasting is carried out at the zone substation level inwhichthisiscriticaltoensuringthatsufficientcapacityisavailableinWestpower’ssub-transmissionandzonesubstation infrastructure. These forecasts are developedusing a zero-based approach from information andrequestsreceiveddirectlyfromcustomers,includingintelligenceonfutureloadtrendssuchasproposeddairyfarmconversions.AsummaryoftheresultsbymajorzonesubstationisshowninFigure1.10.Thisshowsthattheafterdiversitymaximumdemand(ADMD)is50.5MWandthatfuturedemandisexpectedtorisetoaround65MWby2021.

InWestpower’scase,mostofthesub-transmissioninfrastructurehasbeenbuiltwithinthelast25yearsandhasbeenprudentlydesignedtocaterforlikelyfuturedemand,whichmeansthatthereisusuallysufficientcapacitytocaterformarginalloadgrowth.Intheeventofproposalsformajornewloadscrystallising,eachcasewillbeconsideredbothinisolationandincombinationwithotherproposals,tomakesurethatanyimpactsonzonesubstationcapacityaretakenintoaccount.

Figure1.9-TranspowerFeedsfromReeftonandOtira.

KEY Substation

Subtrrans Line 33/66kV

Subtrans Line 110kV

BWR-IGH-A

DOB-BWR-A

AHA-DOB-A

GYM-KUM-A (Leased from Westpower)

KUM-KHA-A (Leased from Westpower)

AHA-OTI-A

ATARAUATARAU

BLACKWATERBLACKWATER

REEFTONREEFTON

DOBSONDOBSONGREYMOUTHGREYMOUTH

( WESTPOWER )( WESTPOWER )

HOKITIKAHOKITIKA( WESTPOWER )( WESTPOWER )

OTIRAOTIRA

ARTHURS PASSARTHURS PASS

KUMARAKUMARA


There isonemajorupgradeproject, tentativelyplannedfor2022, tocater for increasedgeneration inSouthWestland.ThisistheSouthWestlandGridUpgradeProject.

ThisprojectinvolvesupgradingasectionoftheHokitika-Harihari33kVlineto66kValongwithconversionoftheRoss,WaitahaandpossiblyHariharisubstationsto66kVoperation.ApossiblevariationtothisplaninvolvestheoptionofsupplyingtherelativelysmallWaitahaloadatalowervoltagefromnearbyRoss.Becauseofthepoorconditionoftheexistingasset,WestpowerhasalreadystartedtoreplacethepolestructuresbetweenRossandWaitaha,andisplanningtoreplacetheHokitika-Rosssectioncircuitby2012.TheWaitaha-Hariharisectionwillberefurbishedby2013.Thiswillbedoneinsuchawayastofacilitatefutureconversiontothehighervoltageifandwhenthisisrequired.

1.11 Life cycle Management Plan

Westpowerhasadoptedaprogrammetomanagethelifecycleofitsassetsfromdesignandplanningthroughtodisposal.ThemethodologyusedtoprioritiseprojectsisdescribedinmoredetailinSection6ofthisAMP.

Atypicallifecycleofanyassetconsistsofthefollowingstages:

• Designandplanning,

• Acquisitionandinstallation,

• Maintenanceandoperation,

• Disposal.

Forplanningpurposes,Westpowernowusesadecisionsupportsystemthatprioritisescapitalexpenditurebasedonanumberofkeydriverssuchasreliability,equipmentconditionandassetcriticality,andusesthisexpertsystemtoprioritisefutureinvestments.Thejustificationforusingthisapproachistheneedtohaveobjectiveassessmentsoftherelativeimportanceofeachprojectthatiscompetingforscarcecapitalresources.

Asfarasassessmentoffuturereliabilityperformanceisconcerned,probabilisticmethodsareusedfordistributedassetssuchasruraldistributionlines,whereasadeterministicapproachisstillusedforconnectionassetsfeedinglargeloadsasdiscussedinSection5.2.2

http://moss/asset/doc/amp/data/2012 AMP Data 26/01/2012

0

10

20

30

40

50

60

70

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021

MW

Calendar Year

Load Trend(Actual/Forecast)

Dobson Greymouth Kumara Hokitika Reefton Otira Atarau

ADMD (50.5 MW)

Figure1.10-LoadTrend2000to2018ActualandForecast(IncludingLocalGeneration).

EXECUTIVESUMMARY 15

All equipment acquired and installed within Westpower’s network will be new, unless used equipment isacceptedbyWestpoweronanitem-by-itembasis.SuchequipmentwillbeacceptedonlyonconditionsspecifiedbyWestpower.

Maintenanceworkislargelybasedontheconditionoftheassets.Thereisanaturalbusinessdriverintheformoftaxbenefitstomaintainassetsratherthanreplacethem,andthisprovidesacountervailingforcetoapolicyofreplacingolderequipment,ensuringthatareasonablebalanceismaintainedbetweenthesetwoapproaches.

Decommissionedequipmentormaterialsareonlydisposedofwhentheyarenotrequiredascriticalsparesandthereisalowlikelihoodofthembeingrequiredinthefuture.

Themaindriversforthedecision-makingprocessindevelopingtheforwardworkprogrammeare:

• Reliability/securityandqualityofsupply,tomeetcustomerlevelsofserviceandcontractualobligations;

• Occupational health and safety, to establish a safeworking environment and complywith public safetymanagementrequirements;

• Regulatory,tomeetregulationsimposedbyexternalorganisations;

• Environmental,tocomplywithemissionregulationstoair,landandwater;

• Assetperformance/condition,tousehistoricaldatatoassesstheperformanceandconditionoftheassetsandtopredictpotentialremaininglife;

• Cost-efficiency,toensurethatmaximumcost-efficiencyisachievedinaccordancewiththeassetmanagementpolicy;

• Corporateimage,toensurethatanyactivitycarriedoutbytheassetmanagementteamandsubcontractorswillnotdamageWestpower’simage.

1.12 Financial Summary

Typically, 83%of currentmaintenance expenditure on network assets is scheduled in advance (i.e. plannedwork).Another5%ofmaintenanceisnotplannedbutisrequiredtobedoneasrepairstothenetwork’sassets.Theremaining12%ofmaintenanceexpenditureisforremedialwork(i.e.faultrepairs)torestorethenetworktoitsfullinitialservicepotentialfollowingtherestorationofsupplyafterafaultevent.

Capital expenditure typically represents 44%of the total AMP expenditure,whilemaintenance expenditurerepresentstheremaining56%.Table1.11showsthesummaryofforecastexpendituresforthe2013-2022period.

Noprovisionsforinflationhavebeenmadeinthesefiguresbutatransparentcontingencyhasbeenallowed.


Tables1.11and1.12havealsobeenbrokendownintothecategorysub-groupsoffaults,repairsandinspection,serviceandtesting(I,S&T)formaintenanceexpenditure;andreplacement,enhancementanddevelopmentforcapitalexpenditure.

ActualcapitalexpenditurefortheyearendingMarch2011isclosetobudgetonceanumberofprojectsthatweredeferredbecausetheywereno longerrequiredare taken intoaccount.Baselinecapitalexpenditure infutureyearsis lowerthanpreviouslyforecastasaresultofanewfocusoncomponentlevelreplacementforsomeassets, wherebetterconditionassessment informationshows this tobeamoreappropriate strategy.Mostmajorreplacementprogrammesarecomingtoanendafterasustainedperiodofrenewal,andtheforwardcapitalworksprogrammereflectsthis.

1.13 Asset Management Practices

Westpowerisconstantlystrivingtofindmoreefficientwaystocarryoutitsdailyfunctions,byreducingcostsandimprovingproductivity.

The benchmark of best commercial practice is constantly moving, as demonstrated through the industryinformationdisclosureregime,whichlooksatfactorssuchaspriceandsupplyreliability.Therefore,Westpowermustbedynamicandinnovative,andthisculturestartswiththeBoardofDirectors,whichincludessignificantcommercialandfinancialexperience.

AkeystrategicgoalforthebusinessiscompliancewithPAS-55,aglobalspecificationforgoodassetmanagementpractice.Considerableprogresshasbeenmadeinthisarea,withWestpower’sassetmanagementpracticesnowassessedasbeing95%compliantwiththestandard.Section8ofthisdocumentoutlinesthecomplianceissuesindetail,alongwithagapanalysisshowingwherefurtherworkisneeded.Westpowerexpectstobefullycompliantwithinthenext12months.

Westpower encourages suppliers to improve their services and techniques continuously, and, at the sametime,negotiatescompetitivesupplyandmaintenancecontracts.AfullycommercialrelationshipexistsbetweenWestpower and its contracting subsidiary ElectroNet Services, which encourages price efficiency and highproductivitythroughcommercialdiscipline.

ElectroNetServicesprovidesassetmanagementservicestoWestpowerthroughtheassetmanagementgroup.AnumberofsystemsareemployedtooptimisethemanagementofWestpower’sassets.Theseinclude:

• Maximo®,proprietaryassetmanagementsoftwareproducedbyIBMtorecordandanalyseallofWestpower’sassets.Thisprovidesworkordersandfinancialtrackingalongwithassetvaluationmodules.

Table 1.11 - Summary by Category ($’000)

2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

CapitalExpenditure 5962 2509 1804 2164 1979 2049 2292 2806 2782 2492

MaintenanceExpenditure 5023 5250 5410 5573 5701 5584 5818 6097 6406 6702

Total 10985 7759 7214 7737 7680 7633 8110 8903 9188 9194

Table 1.12 - Summary by Activity ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 4180 4361 4468 4580 4650 4477 4648 4862 5099 5323

Faults 541 571 607 641 680 717 759 803 850 899

Repairs 302 318 335 352 371 390 411 432 457 480

Replacement 2414 1235 611 881 727 842 669 1433 1374 1029

Enhancement 2111 260 246 188 228 203 543 164 223 194

Development 1437 1014 947 1095 1024 1004 1080 1209 1185 1269

Total 10985 7759 7214 7737 7680 7633 8110 8903 9188 9194

EXECUTIVESUMMARY 17

• ArcMap® Geographic Information Systems (GIS), to represent Westpower’s assets spatially, with toolsavailabletoprovideinformationsuchasoutagedata.TheGISisinterfacedtotheMaximosystem.

• RealFlex®SCADA,toallowrealtimedataacquisition,automationandremotecontrolofmanyofWestpower’soutstations.

• ETAP®Loadflowsoftwaretoanalysetheeffectofnewconnectionsandloadchangesonthenetwork.

• GentrackVelocity®(customerrelationshipmanagement)softwareisusedtointerfacetotheenergyretailersandMariaregistry,ensuringWestpoweriscompliantwithcurrentlegislation.Allcustomerdataarecollectedformassmarketandtimeofusemetering.

Theconditionofallequipmentisregularlyassessed,andequipmenttechnicalandconditiondataarestoredinacomprehensivedatabase.TheGISsystemisusedtopresentthesedatageographically.

Goodpracticemaintenancetechniquesareemployedwhereverpossibleandthecompanyregularlyexchangesinformationwithotherutilities.Furthermore,thetechnicalawarenessofstaffismaintainedthroughregularstafftrainingprogrammes.

1.13.1 AssetManagementSystemsandInformation

1.13.1.1Technology

Thebasictechnologyinvolvedinthetransmissionanddistributionofelectricalenergyhaschangedlittleoverthelast50years.Nevertheless,smallincrementalchangescontinuetobemadeinthematerialsemployed,leadingto improved performance and higher efficiency.Westpowerwill continue tomonitor these innovations andapplynewtechnologieswhereappropriate.

ThemajorimpactoftechnologyonWestpower’sactivitieswillbeintheareasofinformationtechnology,SCADAoperationofremotepiecesofplantandthepotentialimpactofdistributedgeneration.Bymeansofanongoingdistributionautomationprogrammetosupportthesetechnologies,Westpowerintendstocontinuallyimprovethereliabilityofitsnetworkbyreducingfaultrestorationtimes.

Inresponsetoalackofreliabledisconnectoractuatorproductsavailableonthemarket,Westpowerhasuseditsin-houseresourcestodevelopaninnovativeactuatorthatdeliversthekeyattributesofhighspeed,hightorqueandruggedreliabilityrequiredforthisspecificapplication.AlongwiththeSCADAandcommunicationssystem,thisallowsremotedisconnectorstobequicklyoperatedfromthecontrolroomoverradiolinks(whereasitcouldpreviouslyhavetakenuptoanhourormoreforfaultstafftoreachthesite),leadingtogreatlyreducedpoweroutagetimes.

Furthermore,aprogrammeofreplacingolder,unreliablereclosersandsectionaliserswithnew,highlyautomateddevices,supported,inmanycases,byhigh-speedwirelessradioconnections,iswellunderwayandisprovidingsubstantial benefits. The next stage of leveraging this technology investment tomove toward a smart-gridsolutionofself-healingnetworksisunderactiveinvestigation.

AGISallowsWestpowertovisualiseallaspectsofthenetworkspatially,includinganalysisoftheassetconditionandforwardworkcommitments.Inturn,thisallowsassetmanagementstafftomakeinformeddecisionsthatarecrucialtoachievingoptimalassetmanagementoutcomes.Additionally,theGIShasallowedWestpowertodevelopnewapplicationssuchasviewingthelocationoflightningstrikeswithinthenetworkareainnearrealtime,speedinguptherecoveryfromlightning-relatedfaultsandhelpingtoidentifylightning-proneareas.

Acomputerisedassetworksmanagementsystem(anIBMproductcalledMaximo®)isabest-of-breedsolutionthathasbeenintroducedtomaintainacompletemaintenancehistoryforeachassetandtoensurethatregularscheduledmaintenanceiscarriedoutwhenneeded.Thisincludesastructuredjobcostingsystem,whichensuresthatanycostsincurredonthenetworkareaccuratelyallocatedtotheappropriateassets.Thissystemdividesnetworkexpenditureintoappropriateactivities(namelyI,S&T;faults,repairs,replacements;enhancementsanddevelopment),aswellasassettypeandlocation.Detailedreportsincludingcapitalandoperatingexpendituremaybegeneratedatanytime.


Whenmaintenanceisrequired,livelinemaintenancetechniqueswillbeusedwhereverpossibletoreducethenumberanddurationofpoweroutages.Westpower’s linecontractor is trained in live linegloveandbarriertechniques, and has all of the specialist equipment needed to provide a high level of repair service.Manymaintenancetasksinvolvingvoltagesfrom400Vto33,000Vcannowbecarriedoutwithouttakingthepowerofffromcustomers.

Newtechnologieswillcontinuetobeemployedwhereassetmanagementengineersaresatisfiedthatitcancost-effectivelyandreliablybeemployedtoimproveservicequalityandperformance.

1.13.1.2Information

Adequate and accurate information is a fundamental need in order to manage assets efficiently. Historicinformationabouttheassetscurrentlyinplaceexhibitedsomegapsbecausepreviousrecordswereinconsistentandlackedsufficientdetailinareassuchasequipmenttype.

Westpowernowhaspracticesestablishedforcontractorsto improvethis informationbycollecting“as-built”informationonsurroundingassetswheneversignificantworkiscarriedoutinthefield.Moreover,anongoingprogrammeofcollectingdatatoafinerlevelofgranularity,includinglowvoltageandserviceassets,ispayingdividends.

Accuraterecordsarealsobeingobtainedforallnewandreplacementworkcarriedoutonthenetwork.

1.14 Risk Management

Westpowerhas a separateRiskManagement Plan (RMP) completed as part of its overall business planningstrategy.Thisincludesbusinessimpactanalysisandbusinesscontinuityplanning.

Inaddition,WestpowerisactivelyinvolvedinaregionalLifelinesprojectlookingatwaysofmanagingtherisksinvolvedwithmajordisastersandensuringthatplansareinplacetodealwithmostofthelikelyscenarios.

Riskmanagementpracticeshavebeenembracedasameansofensuring thatall commercial risksare takenintoaccountandappropriatestrategiesareinplacetomanagetheserisks.Inthisway,thelong-termviabilityofWestpowerisprotected.

AfullRMPhasbeencompletedafteranin-depthlookatWestpower’soperationsandenvironmentinconjunctionwithriskmanagementconsultants.

Thefollowinggeneralriskcategoriesareconsidered:

• Futureplanning,

• Businessdevelopment,

• Operations,

• Contractormanagement,

• Financialmanagement,

• Staffmanagement,

• Occupationalhealthandsafety,

• Publicsafety,

• Emergencymanagement,

• Informationsystems,

• Informationmanagement,

• Environmental,

• Facilitiesmanagement,

EXECUTIVESUMMARY 19

Atallstagesthroughtheassetmanagementplanningprocess,Westpower’sstaffstrivestoreducetheimpactofsuchrisks.

1.14.1 BusinessContinuityPlan

The Business Continuity Plan is defined by each department and enables the re-establishment of normalprocessesandproceduresfollowingamajordisruptiveeventwhichresultsineitherthelossofbusinesspremises,resourcesorpeople.

1.14.2 EmergencyManagementTeam

TheEmergencyManagementTeam(EMT)hasStandardOperatingProceduresthatprescribetheappropriateprocessesandassignresponsibilitiesfortheconductoftheEMTintheeventofadisasterofsuchproportionsthatrequirescoordinatedcommandandcontrol.

1.14.3 HealthandSafetyManagement

Operatingandmaintaininganelectricalnetworkinvolveshazardoussituationsthatcannotfeasiblybeeliminatedentirely.Westpoweriscommittedtoprovidingasafe,reliablenetworkandahealthyworkenvironmentbytakingallpracticalstepstoseethatouroperationsdonotplaceourstaff,communityorenvironmentatrisk.Hazardoussituations are controlled through training, appropriate guidelines, andWestpower standards and operatingprocedures.Wealsorequirethatanyhazards,particularlyelectricalhazards,mustbetakenintoaccountwhennewnetworkinstallationsarebeingdesignedandconstructed.

UnderthenewElectricity(Safety)Regulations2010,Westpowerhasapositiveobligationtoinstituteapublicsafetymanagementsystemtoensurethathazardstothepublicareproperlyassessedandevaluatedandthateffectivemitigationplansareputinplace.Westpoweriswellalongthewaytohavingitssafetymanagementsystem,basedonNZS:7901,inplaceandreadyforauditbyApril2012.

1.14.4 EnvironmentalManagement

Westpoweriscommittedtoapolicyofenvironmentalsustainability,asdiscussedinitsEnvironmentalPolicy.

Thefollowingtopicsarecoveredinthispolicy:stakeholderconsultation,protectionofthebiosphere,sustainableuseofnaturalresources,reductionanddisposalofwaste,wiseuseofenergy,riskreduction,restorationoftheenvironment,disclosure,commitmentofmanagementresources,assessmentandannualauditing.

Oilspillmanagementsystemshavebeeninplaceformanyyearsnowand,todate,havesuccessfullymanagedanysignificantspills.ASF6monitoringprogrammeisalsobeingactivelypursuedtoreducetheriskofleakageofthisgreenhousegas,whichisusedinmosthigh-voltageswitchgear.

1.14.5 ImpactofNaturalDisasters

WestpowercommissionedareviewoftheWestCoastLifelinesstudyin2004andagainin2006toassesstheimpactofanaturaldisasterontheWestpowernetwork.Earthquakes,stormsandtornadosareWestpower’smajor natural disaster risks. Overall, the studies have concluded that there is a very high dependency oncommunicationsaswellasaclearneedtohavetheairportsandportsavailableaftertheevent.Anelectricitysupplywouldbeessentialforalmostallserviceauthoritiesintherestorationperiodfollowinganaturaldisaster.Sincetheoriginalstudyin2004,furtherdetailedstudiesandactionshavebeenimplementedtominimisetheoverallrisktothenetworkinacost-effectivemanner.


1.14.6 AssetFailure

Thefailureriskforallkeyassetshasbeenassessedbasedonknownpastperformance.Modernpartialdischargedetectiontechnologyhasbeenemployedtomanagetheriskofprematurefailureandtoplanforanend-of-lifereplacementstrategy,especiallywhere11kVmetal-cladswitchgearisconcerned.AregularDissolvedGasAnalysis (DGA) and Polarisation De-polarisation Current analysis (PDC) oil testing programme is carried outonWestpower’s zone substation transformers tomonitor their condition andhighlight potential issues. Thetwomajorassetclasses thatpresent thehighest riskof failureare the33kVand11kVmotorisedair-breakswitchesandDominionDropOut(DDO)fuselinks,andprogrammesareinplacetoupgradethesecomponentsprogressively.

Insulatorsoncriticaloverheadlinesarenowbeingcheckedwithacoronacamera.Thisisanewtechnologythatcanhighlightexcessivedischargeonlineinsulatorsthatisnotnormallydetectablebyothermeans.Itisbeingusedtodetectfaultsandtoassessthegeneralconditionofinsulators.

Allnewassetsthatareproposedforuseonthenetworkarethoroughlyvettedbyaninternalmaterialsevaluationgroupthatconsidersissuessuchassafety,technicalperformanceandlongevitybeforeapprovalfortheiruseisgiven.

1.15 Plan Outcomes

Themajoroutcomeofthisplanisaten-yearexpenditureforecastthatischaracterisedby:

• Arelativelyconstantlevelofinvestmentinnewconnectionsandextensionstothenetwork.Thisisbasedonanoverallmodestgrowthlevelwithpocketsofhighergrowthinspecificareas;

• Theongoingmaintenancecostofregulatorycompliancewiththetreeregulationsandadditionalrequirementsfortreeworkersafety;

• Materialcostincreasesthatarecontinuingtoaffectourconstructioncostsbecauseofthecombinedeffectofrawmaterialdemandandexchangeratefluctuations;

• Amoveawayfromreplacementstrategiestoamorefocussedandproactiveconditionassessmentregime,supported by repair and refurbishment programmes that reflect the very good overall condition of theexistingassets.Thisisreflectedinthereducingforwardcapitalexpenditurerequirement.

Thisdocumentispubliclyavailable,andwewelcomeconstructivecommentsandsuggestions.

Commentsmaybemadeinwritingto:-

RodgerGriffiths

GeneralManagerAssetsandEngineeringServices

WestpowerLimited

P.O.Box375

Greymouth7840

NewZealand

Email:[email protected]

INTRODUCTION 21

2.0 INTRODUCTIONThisisthe20thAssetManagementPlan(AMP)tobeproducedforWestpoweranditincludesonlyminorchangesfromlastyear,includingchangestoaddressthecommentsmadeintheCommerceCommission’sreviewoftheWestpowerAMPreportedin2011.SomeareasofnoteincludechangesinSection6tofocusontheplanningprocessesusedincreatingthenetworkdevelopmentplanand,inparticular,themethodologyusedtoprioritisedevelopments.Changeshavebeenmade to focusonmajorprojectsandprovide increaseddetail about theindividualprojectscopesandassociatedjustifications.

TheAMPdefinestheserviceobjectivesandgivesaclearfocusonlifecyclemanagementbypresentingoperations,maintenance and renewal policies, needs and programmes by asset type. The AMP processes adopted byWestpowerhavebeenchosentointegratebestpracticefeatureseffectively.Theseestablishtheservicestandardsandfuturedemandstomeetbusiness, legislativeandotherneeds,whiledevelopingoptimumlifecycleassetmanagement strategies, and resulting cash flowprojections, based on assessing non-asset solutions, failuremodes,cost/benefitsandrisk.

2.1 Background

2.1.1 PurposeStatement

ThepurposeofWestpower’sAMPistodocumenttheassetmanagementpracticesemployedbyWestpowerto strategicallymanage its assets and tomeet the requirements of the Electricity Distribution (InformationDisclosure)Requirements2008alongwithChapter4oftheElectricityInformationDisclosureHandbookissued31March2004andamended31October2008.

DeterminingofthelevelofcompliancewiththeaboverequirementsisassistedbyAppendixB,whichprovidesa cross-reference showingwhere the particular elements called for in the legislationmay be found. This isimportantbecausethedocumentisstructuredinsuchawayastogroupassettypestogether,ratherthantheactivitygroupingusedintheHandbook.Alloftherequiredinformationisprovidedtoahighlevelofdetail,butthecompliancereviewerisreferredtoAppendixBasameansofnavigatingthevarioussectionsofthisdocumenttodeterminewherethekeyelementsmaybefound.

Itisalsointendedforgeneralviewing,assuringWestpower’sstakeholdersthattheWestpowernetworkcontinuestobemanagedinaprofessionalandcost-effectivemanner.Figure2.1showsthebasisfortheassetmanagementsystemusedbyWestpower.

This AMP covers a period of ten yearsfrom the financial year beginning on 1April2012untiltheyearending31March2022. Themain focus of analysis is thefirst three tofive years; for this period,mostof thespecificprojectshavebeenidentified. Beyond this time, analysistends to be more indicative, based onlong-termtrendsanditislikelythatnewdevelopment project requirements willarise in the latter half of the planningperiod.Theseprojectrequirementsmaynotbedefinedhere.

Figure2.1-TheWestpowerAssetManagementSystem


Toprovidea framework for assetmanagementwithin theplanningperiod, it is necessary todetermine thelonger-termdirectioninwhichthenetworkshouldbedeveloped.Forexample,itwouldnotbeprudenttoinvestheavily inenhancingasystemataparticularvoltage if,beyondtheplanninghorizonbutwellwithin the lifeofthoseassets,itislikelythattheywouldbeoverlaidbyanewhighervoltagesystem.Furthermore,strategicdevelopmentplanningmustberesponsivetoarangeofscenariosthatmightoccur.

ThisplanwasapprovedbyWestpower’sBoardofDirectorsonthe1stMarch2012

ThenextplanwillbepreparedandpublishedbyMarch2013.

2.1.2 ObjectiveofthePlan

ThedefinedobjectiveofthisWestpowerAMPis:

“ToprovideasystematicandcoordinatedapproachtotheoptimummanagementofWestpower’sphysicalassetsandtheirassociatedperformance,risksandexpendituresovertheirlifecycleforthepurposeofachievingtheorganisationalstrategicplanandtosatisfystakeholdersrequirements.”

2.1.3 RelationshipwithOtherPlanningDocuments

ItisimportantforstakeholdersthatthemannerandthebasisuponwhichthisAMPisintendedtooperateareclearlyunderstood.Forthepurposesofclarity,andinordertoavoidanyconfusion,thefollowingunderlyingassumptionsneedtobetakenintoaccountbythestakeholdersindealingwiththisAMP:

• ThisAMPinteractswithotherWestpowerworkingplans.Ofparticularimportancearetheannualbudgets,whichsetoutthespecificresourcesrequiredforassetmanagementactivities.Thosepartsof theannualestimatesrelatingtothemanagementofthesystemarebasedontheannualAMPs.

• AuthorisationofexpenditureresultsfromapprovaloftheannualestimatesbytheBoardofDirectorsandfromspecificapprovals.ThisAMPdoesnotrepresentanauthorisationbyWestpowerforexpenditure,nordoesitrepresentacommitmentonthepartofWestpowertoproceedwithanyspecificprojectsorprogrammes.

Figure2.2belowshowstheinteractionofthedifferentWestpowerplansandstakeholdersinvolved.

Figure2.2-RelationshipWithOtherPlansandApprovalProcess

INTRODUCTION 23

2.1.4 AssetsCoveredinthisPlan

This AMP includes Westpower’s assets that transport electricity (owned by the electricity retailers) fromTranspower’s seven Grid Exit Points (GXP) to over 13,000 electricity consumers on theWest Coast of NewZealand’sSouthIsland.

TheWestpowernetwork includes110kV,66kVand33kVsubtransmissionnetworks.The66kVnetwork issuppliedfromTranspowerGXPsatGreymouth,Hokitika,Kumara;the33kVnetworkfromDobsonandHokitika.An11kVsystemissuppliedfromTranspower’sOtiraGXPwhilstReeftonhasa110kVsupplyfromTranspower.

Westpowerhasnetworkassetsthroughoutthe18,017squarekilometresoftheWestCoastfromLyell inthenorthtoParingainSouthWestland,withatotalofaround40,000assetsin76classifications.

Thedistributionsystemcomprises2151circuitkilometresofAlternatingCurrent(AC)distributionlines,21zonesubstationsandswitchyardsstrategicallylocatedthroughoutthenetworkwhich,inturn,providean11kVsupplyfordistributionto2347distributionsubstations,onecontrolroomandatelecommunicationsnetwork.

Westpower’sdistributionlinesconsistofvaryinglinecapacities,dependentuponlocaldemandsandgeographicalconsiderations.Operatingvoltagesinclude110kV,66kV,33kVand11kV.Theselinesinvolvealargepopulationofpoles,transformers,disconnectorsandotherassetsofvaryingtypesthatareessentialtothedistributionofelectricity.

Themaintenanceofthenetwork iscarriedoutbyElectroNetServicesasthepreferredcontractor,which isawhollyownedsubsidiaryofWestpower.Theyarecontractedtoundertaketheinspection,servicingandtesting(I,S&T),alongwithfaultcalloutandfaultrepairwork.Majorlinereplacement,enhancementordevelopmentprojectsarealsoissuedtoElectroNetServicesasdesignbuildcontracts.

2.1.5 IssuesFacingWestpower

AMPsmustaddressgrowth.ProjectionsfortheWestCoastarecontinuallystudiedbyWestpowertoensurethatthecapacityandperformanceofthesubtransmissionanddistributionnetworksareadequateforthedemandandtypesofloadconnected.Thisplanprojectsthatthecurrenttotalloadofaround50.5MWwillbearound75MWintenyears’time.

Thisprojection isdependentonproposed industryprojectsproceedingbut in thecurrenteconomicclimate,thereisnocertaintyofthis.Forthisreason,thisAMPisfocussedonmaintaining(orimproving)thereliabilityofthenetworkandcateringforincrementalgrowthonthebasisthatlargerindustrialdevelopmentswillrequireproject-specificaugmentationsthatwillonlyproceedoncethevariousprojectsarecommittedandconnectioncontractsaresignedwithdevelopers.

KeyassetmanagementissuesfacingWestpowerare:

• Maintainingnetworkperformanceandreliability,includingsettingclearlydefinedservicelevelsandbackingtheseupwithcustomerguarantees(refertoSection4)

• Thecostofenvironmentalimprovementsandeasementsthatneedtobefactoredintoplanning;

• Decision-makingbetweenmaintenanceofassetsandtheirrenewalwillbeamajorpartofassetmanagement(refertoSection5)

• Acquiringrevenuefundingthroughapricingstructureatalevelthatisalsoacceptabletocustomers(refertoSection7)


2.1.6 Westpower’sOrganisationStructure

Westpower Limited is a stand-aloneElectricity Lines Business (ELB) witha contracting subsidiary, ElectroNetServices Limited. Westpower isessentially an electricity distributioncompany that is a shell or holdingcompany; however, it will continueto own the infrastructure assets. The100% owned subsidiary contractingcompany ElectroNet Services performsnot only work on the Westpowerinfrastructure assets but also the assetmanagement function under contractfrom Westpower. The structure of theWestpower Group is shown in Figure2.3.

• Mitton ElectroNet is based inChristchurchandistheresultofarecentmergerbetweenMittonConsultingandtheChristchurchofficeofElectroNetServices.MittonElectroNetLimitedis100%ownedbyElectroNetServicesLimited.

• AmethystHydroLimitedisajointventurecompanywithWestpower(88%ownership)andHarihariHydroLimited (12%ownership) tobuild, ownandoperate a6MWhydro schemeon theAmethystRivernearHarihari.

• ElectroNetTransmissionisarecentventureinvolvingtheacquisitionofABB’s linesdivisioninNelsonandGreymouthon1Aprilof2008.

ApartfromtheBoardofDirectors,aChiefExecutiveandtheWestpowerAssetManager,whoallworkdirectlyforWestpower,allotherstaffareemployedbyWestpower’ssubsidiaryElectroNetServices.

2.1.6.1 GovernanceandBoardApprovalProcesses

TheBoard sets thehigh-levelbusiness goals and strategies, and theChief ExecutiveandAssetManagerareresponsible for implementing them throughElectroNet Services. Inparticular, theBoard approves the assetmanagement policy that articulates the Board’s overarching expectations for management of Westpower’sassetsandthisprovidesavaluablegovernanceframeworkwithinwhichallassetmanagementactivitiesmusttakeplace.

TheAMP itself isapprovedby theBoardeachyearandprior to thestartof thefinancial year.This includesimplicitapprovalforallincludedprojectsuptoanindividualvalueof$50,000.

Allprojectswithavaluegreater than$50,000are subject toa furtherandseparateBoardapprovalprocessinvolvingthedevelopmentofaseparatebusinesscaseusingapre-definedtemplate.WhilefinancialmeasuressuchasNetPresentValue(NPV)andInternalRateofReturnareappropriateKeyPerformanceIndicators(KPIs)forsomeprojects,manyothersinvolvetheevaluationofkeydriverssuchasreliabilityofsupplyorhealthandsafety.MoredetailsareprovidedinSection6regardingtheparticularplanningcriteriathatareapplied.Theseprojectsmayonlyproceedafterspecificapprovalisgiven.

Financial Reports are provided to the Board on amonthly basis and these include budgeted versus actualexpenditureforallworkrolleduptotheoverallactivitylevel.Inaddition,individualjobcostreportsareprovidedforthemajorprojectsapprovedbytheBoardasdiscussedinthepreviousparagraph.

Fig2.3-WestpowerGroupCorporateStructure

INTRODUCTION 25

Exceptionreportsaretobeprovidedonallprojectswithavalueofmorethan$50,000thatexceed,orarelikelytoexceed,thebudgetedfigurebymorethan20%,includingthereasonsforthevariance.

2.1.6.2 BoardReport

Thefollowingadditionalreportsarealsoprovidedtotheboardeachmonth:-

• Billingstatistics-ThisreportshowstheallocationofsalesamongstthevariousretailersactiveonWestpower’snetwork,bytariffcategory.

• Network delivery performance - This shows monthly peak demands in megawatts and consumption inmegawatthoursforthecurrentyeartodateandtheprevioustwoyearsforcomparativepurposes.

• SAIDI - Amonthly progressive SAIDI report is provided in both tabular and graphical format, alongwithexplanationsofmajorevents.ThisreportshowsboththerawSAIDIstatisticsandthebaselineSAIDIresult,excludingMajorEventDays (MED’s)using the2.5betaapproachdevelopedby InstituteofElectricalandElectronicEngineers(IEEE).

• SAIFI-ThisreportisproducedingraphicalformatonlyandprovidessimilarinformationtotheSAIDIreportbutfocusesonSAIFI.

• Legislativecompliance-Areviewoflegislativecomplianceisprovidedtotheboardeachmonthandanynon-compliancesarenoted.

2.1.6.3 Westpower’sMissionandVision

MissionAWestCoastcompanyoperatingsuccessfulbusinesseswhichprovidefirst-classelectricaland

technologysolutions,whereverourcustomerstakeus.

VisionRecognisedforexcellenceinalllinksoftheelectricityvaluechain.

2.1.6.4 StatementofCorporateIntent

Salient statements fromtheStatementofCorporate Intent (SCI) that relate tomanagementofWestpower’sassetsinclude:

• TocontinuetoprovideWestCoastcommunitieswithasafe,secure,sustainableandcost-effectiveelectricitydistributionnetwork;

• ToensureobligationsundertheEnergyCompaniesAct1992,theElectricityAct1992,theElectricityIndustryreformAct1998andtheirvariousamendmentsandregulationsaremet;

• TocontinuetolobbyonbehalfofWestCoastconsumerstoensurethatareliabletransmissionnetworkismaintainedintotheWestCoast.

2.1.6.5 AssetManagementPolicyStatement

ThekeydocumentlinkingWestpower’sbusinessobjectives,asoutlinedintheSCI,withtheassetmanagementsystemistheAssetManagementPolicy,whichdefinesthehigh-levelpolicyobjectivesthattheBoardexpectsallassetmanagementplanningtoachieve.Assuch,itisanoverarchingdocumentthatisembeddedintheassetmanagementsystem.


Thepolicyfollows:

Wearecommittedtomaximisingourshareholders’investmentsinalegallyandenvironmentallycompliantandsustainablemanner,withoutcompromisingthehealthandsafetyofouremployees,consumers,orthepublic.Weshallachievethisbyadoptingthefollowingpolicystatement.

Safety


Reliability

• Reliability of supply - Through continued investment in relevant technology and system configuration,reliabilitymustmeetapprovedtargetsatalltimes.

• Qualityofsupply-Qualityofsupply,commensuratewiththeloadtypeandcriticality,mustmeetWestpower’sstandards.Remedialactionwillbetakenwherestandardsarenotmet.

Security

• Securityofsupply–Thedesiredlevelofsecurityisdefinedbygoodindustrypractices,andlong-termplansmustbedevelopedtoachievetherequiredsecurity.


Sustainability

• Maintainservicepotential-ThefutureofWestpower’sbusinessiswhollydependentontheabilityofthenetworktocontinuetoprovideservicefortheforeseeablefuture.Everyeffortmustbemadetomaintaintheongoingservicepotentialofthenetworkwhereappropriate.

• Supporting economic growth -We recognise the electricity infrastructure as a key enabler of economicgrowth,andwillworkwithcurrentandfuturedeveloperstoprovideelectricitywiththecapacity,securityandqualityrequiredtosupporttheirbusiness.

• Continual improvement–Theassetmanagementsystemwillbereviewedonanannualbasisandwhereweaknessisfound,improvementswillbemade.CompliancewithPAS-55:2008shallbesupported.

• Strategicandlong-termplanning–Ourinfrastructurebusinessinvolveslong-terminvestments,andwewillensureourdecisionsalignwithandsupporttheorganisation’sstrategicplan.

• New investment – Any new investmentmustmeet the shareholders’ expectations and approval wherenecessary.

• Communication – The requirements of the asset management system must be communicated to allstakeholders to enable them to be aware of their obligations and to ensure that their expectations areconsideredinallaspectsofplanning.

Cost-efficiency

• Cost-efficiency-Allprojectsmustcompeteforfinancialresources.Prudentassetstewardshiprequirescarefulbudgetingandrobustfinancialreviewprocessestoensuremaximumcost-efficiencyisassured.Opportunitiesfor improved productivity through training, technology, process improvements or othermeans shall beconstantlypursued.

• Energy-efficiency–Energy-efficiencyisencouragedinallareasofWestpower’sactivitiesandwillcontinuetobeakeyoutcomefromthedesignprocess.Whereopportunitiesexisttoenhanceenergy-efficiencyforexistingassets,theseareactivelypursuedandimplementedwheretechnicallyandeconomicallyfeasible.

INTRODUCTION 27

• Technology-Technologyisseenasakeyenablerinprovidingimprovedserviceandvaluetoourconsumers.WewillcontinuetokeepabreastofdevelopmentsinthefieldofnewandemergingtechnologyandapplythesetoWestpower’snetworkwhereappropriate.

• Fairpricing–Thepriceofelectricitytoconsumersmustbetransparentandfairtoallusersoftheassets.

• Capitalcontributions–Anyexpensefornetworkextensionstosupplynewloadswillbemetbyaconsumercontributiontowardsthecostsinvolved.

Environmental impact

• Environmentalimpact-Westpowerisenvironmentallyresponsibleandcarefullyconsiderstheenvironmentalimpactofanyofitsactions.Furthermore,thecompanyworkshardtomitigateanynegativeeffectsandtoprovideanetenvironmentalbenefitwherethisispractical.

Risk management

• Risk management – Westpower adopts the AS/NZS ISO 31000:2009 standard in its approach to riskmanagement and has a groupRiskManagement Plan (RMP) that includes business impact analysis andBusiness continuity planning. The asset management system will develop an RMP directly related toWestpower’sdistributionassets.

Legislation

• Legislativecompliance–TheAssetManagementSystem(AMS)mustmeet all relevant legislation. Where non-compliance issues areidentified,thesewillbedealtwithpromptlyandtransparently.

TheassetmanagementandplanningprocessesdiscussedthroughouttherestoftheAMPhavebeendevelopedtodirectlysupportthispolicyandmustadheretoit.

Theassetmanagementdivisionholdstherequisitetechnicalknowledgeandisresponsiblefortechnicaldecisionsregardingtheasset.Inaddition,thisdivisioniseffectivelythe“custodian”oftheassets,andtheirdutiesincludetakingresponsibilityforallperformanceandsafetyissues.

ThecompanystructureisshownintheFigure2.5andalsoinFigure2.6,detailingtheassetmanagementdivision.

2.1.6.6 CorporateStructure

Thekeyfunctionsofthegroupsare:

• BoardofDirectors

The Board provides overall governance of the Westpower group ofcompaniesandensuresthatthefollowingfourpillarsofgoodgovernancearemaintained(Figure2.4showstheprocessfor“Sign-off”bytheBoard)

1. Determinationofpurpose–Drivesthecompany’spurpose,goalsandstrategy.

2. Governanceculture–Ensuresoperationwithinahigh-performanceculture that deals effectively with the right issues in the rightmannerandencouragesdebateand candour. Itmaintainseffectiverelationshipswithshareholdersandotherstakeholders.

3. Holdingtoaccount–Holdsmanagementtoaccountthroughinformed,astute,effectiveandprofessionaloversight.

Figure2.4-ProcessforBoardSign-off


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INTRODUCTION 29

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4. Compliance–Ensuresthecompanyisandremainssolvent,andensurestheprobityoffinancialreportsandcompliancewithregulatoryenvironments.

• CEO

The CEO oversees the financial performance of Westpower, management, the company secretariat andmaintenanceofrevenuestreams.

• GeneralManager–AssetsandEngineeringServices

The Manager oversees the network to maximise system availability. His/her duties include developingmaintenancestrategies,settingandmanagingpriorities,controllingstandardsandissuingworkorderstoensurereliabilityatminimumcost.He/shealsoactsasthekeycontactpointwithenergyandgenerationcompanieswishingtousetheWestpowernetworkforthedistributionofelectricity.

2.1.6.7 AssetManagementRoles

TheassetmanagementdepartmentisundertheoverallcontroloftheGeneralManager–AssetsandEngineeringServices.

Aseriesofteamleadersareresponsibleforthevariousactivitiescarriedoutbytheassetmanagementdivison.Therolesofeachoftheseteamleadersarediscussedbelow.

• SeniorElectricalEngineer

TheSeniorElectricalEngineerisresponsibleforsettingengineeringpolicyaswellasoverseeingallengineeringdesign. He/she is also responsible for reviewing non conformance in the network and ensuring that theappropriatestandardsareinplace.

• AssetSupportOfficer

TheAssetSupportOfficerisresponsibleforallmatterssurroundingthecollectionofmeteringdataandbillingofretailers.Thisincludesreconciliationactivities.

• NetworkManager-Lines

Thisroleinvolvesthemanagementofallhigh-voltage(HV)andlow-voltages(LV)linesassetsownedbyWestpower,includingcontrolandmanagementof theGeographic InformationSystem(GIS)andvegetationmanagementprogrammes.

• SCADA/CommunicationsEngineer

The SCADA/Communications Engineer is responsible for all of Westpower’s Supervisory Control and DataAcquisition (SCADA) and communication assets, including data communication in the network, and SCADAcontrolofsubstationsandswitchingassets.

• NetworkManager-Stations

TheNetworkManager -Stations looksafterall thezonesubstationsandnetworkswitchingassets, includingmaintenanceanddevelopment,andappliesthepoliciesdevelopedbytheSeniorElectricalEngineer.Thisrolealsoincludesresponsibilityforthecontrolroomandtheday-to-dayoperationsofthenetwork.

2.1.6.8 RelationshipbetweenAssetManagementandOperationsDivisions

TheassetmanagementdivisionassumestheroleoftheassetownerandisresponsibleformanagingtheinterestsofWestpowerand, inparticular,maintainingtheservicedeliverypotentialandperformanceofWestpower’sassets.

Theoperationsdivisionfulfilstheroleoftheserviceproviderandisresponsibleforcarryingoutallmaintenanceanddevelopmentontheassetsatthephysicallevel.

INTRODUCTION 31

The relationshipbetweenassetmanagementand theoperationsandfinancedivision isbasedonanarms’-lengthcontractbetweenWestpowerandtheoperationsdivisionofElectroNetServices,withassetmanagementeffectivelyactingasWestpower’sagentandbeingdirectlyunderthecontroloftheWestpowerassetmanager.

2.1.6.9 OperationsDivisionRoles

Withintheoperationsdivision,managersareresponsibleforparticularareasofworkasfollows:

• ElectricalSupervisor/ProjectManager

Thisroleisresponsibleforthetestroom,electriciansandelectricalfitterswithinzonesubstations.

• OperationsManager

TheOperationsManager isresponsibleforall linestaff, including linemechanicsandfaultstaff,alongwithasmallnumberoffitterswhoworkondistributionsubstations.

• OfficeManager/Accountant

ThisrolemanagesthebackofficefunctionsofElectroNetaswellasstoresandprocurement.

2.1.6.10BoardReport

2.1.7 Westpower’sStakeholders

Stakeholders aredefinedas thosepartieswithan interest inWestpower’s assetmanagement. Theprincipalstakeholdersare:

• Consumers;

• Shareholders(WestpowerisownedbytheWestCoast);

• ElectricPowerTrust,awhollyownedconsumerTrust;

• TheBoardofDirectors;

• Employees;

• Contractors;

• Retailers.

ThesecondarystakeholdersthatmayhaveaninterestoropinionintheaffairsofWestpowerare:

• Auditors,

• Governmentagencies,

• Suppliersandgenerators,

• Transpower,

• Landowners,

• Insurers,

• Financialinstitutions,

• Externaladvisors,

• Pressuregroups,

• Pressandmedia.


2.1.7.1 IdentificationofStakeholderInterests

Retailers and Customers

Westpowerhasliaisedcloselywithenergyretailerstodeterminetheexpectationsoftheircustomersandquantifytheseintermsofdesirablereliabilityindices.Westpowerhasconducteditsownconsultationwithits25largestcustomersanddiscussedalternativecombinationsofpriceandqualitythatmaybeavailabletocustomerswhocommittoacommercialcontract.

Massmarket customers have not expressed any dissatisfaction in the status quo combination of price andreliability.Someofthe25largestcustomershaveexpressedaninterestinpayingforadditionalreliability,mainlybasedonthecriticalityoftheiroperations.

Themaininterestsforretailersandcustomershavebeenidentifiedasreliabilityintermsofcontinuousavailabilityofsupply,restorationofsupplyandadequateshutdownnotification,aswellasreceivingtimelyandup-to-dateinformationifanoutageoccursonthenetworksothattheycanplanaccordingly.

OtherinterestsarethatWestpoweriscost-effectiveinitsservicedeliveryandprovidesagoodqualityofserviceintermsofbothmaintenanceandpowerquality.

Finally,stakeholderswishtobechargedafairprice,withsupportinginformationbeingmadeavailabletojustifythatprice.

Theseinterestsareaccommodatedintheplanby:

• TheSAlDlreliabilitytarget;

• Thegapanalysisonassetsegmentstoensureeachcustomerisreceivingthepromisedstandardofservice,andthetargetingofexpenditureaccordingly;

• Reinvestmentinrenewals;

• Strongcustomerconsultationcommitment;

• Directcustomerbilling,includingamoveawayfromenergy-basedtodemand-basedchargesforallcustomers;

• Supplypointand-density-basedpricingstructure;

• Customers’expectationsofgoodserviceatafairprice,aswellasacontinueddistributionbyshareholdertrusts;

• Theefficiencyofthecompanyasjudgedbycustomersbythesizeofthedistribution.

Retailers’ interests are identified through communication and direct discussion. Retailers are interested insellingenergytocustomerswithlittlebarrierstocompetition.TheirinterestsareaccommodatedintheplanbyWestpower’sdirectbillingprogramme.

Shareholders

Westpowershareholder’swishtoensure,asownersoftheassets,thattheirfinancialcapitalisprotectedinthelongtermbyensuringthattheoperatingcapabilityofthesystemisprotectedandthatthesystemismaintainedefficientlysothattheyearnanacceptablereturnontheirinvestment.

The shareholders also have an interest in howWestpower provides customer service and how itmeets itsobligationstootherparties(asdescribedbelow).

The interests of Westpower’s shareholders are identified through the SCI process and consultation withshareholders.Shareholdersareinterestedin:

• Anacceptablereturnbeingearnedfromtheassets;

• Anacceptablecashreturnfromthenetwork;

INTRODUCTION 33

• Thebusinessbeingsustainableinthelongterm;

• Areasonablestandardofservicebeingprovidedtocustomers;

• Thepricetocustomersbeingequivalenttothatchargedinotherruralareas;

• Customersatisfaction;

• Anetworkthatmeetsacceptableindustrysafetystandards.

Itisnotedthattheaboveinterestsarenotnecessarilyachievableintotalityifrevenuesarelimitedtobelowanacceptablereturn.

Theaboveinterestsareaccommodatedintheplanby:

• Therequirementthatanycustomer-drivendevelopmentworkcoversatleastitscostofcapital;

• Fundingdevelopmentworkthatisexpectedtoproducefuturerevenuebydebt,ratherthanreducingcashreturnstoexistingcustomers;

• TheSAlDlreliabilitytarget,i.e.strong,buttargetedre-investmentinrenewalstoprovidealong-termsafeandsustainablenetwork.

Westpower’sabilitytoearnanacceptablereturnonassets isconstrainedbytheneedforpricestability.Theorganisationcaneitherlimitinvestmentinnewcustomer-drivenworkifacceptablereturnscannotbeearnedor,alternatively,requireacapitalcontributionfromthecustomertocoveranyshortfall.Investmentinexistingassetsis,however,asunkcost.

Board of Directors

Westpower’ssharesareheldbytheWestCoastElectricPowerTrust(WCEPT)onbehalfofthecapitalbeneficiarieswhocomprisetheelectorswithinWestpower’sarea.Assuch,theWCEPTistreatedasthenominalshareholder,orownerofthebusiness,whichisadministeredbyaBoardofDirectors.

TheWCEPTisregularlykeptinformedofkeymattersthroughtheannualissueofanSCI,six-monthlyfinancialreports,andshareholders’newsletters.Eachyear,WestpowerandtheWCEPTmeettogetheraftertheirrespectiveAnnualGeneralMeetingstodiscussissuesofmutualinterest.Additionally,theChiefExecutiveorChairpersonwilloftenattendregularWCEPTmeetingswheninvitedtopromotegoodcommunicationandansweranyconcernsthatmayarise.

TheaboveinterestsareaccommodatedintheplanbyprovidingdirectreportingtotheBoardofDirectors intermsofannualbudgetproposals,majorprojectapprovals,monthlyfinancialreports,projectexceptionreportsandtheAMP.

Employees and Contractors

OtherpartieswithapotentialinterestinWestpower’sassetmanagementincludeworkers(includingcontractors)whophysicallyworkon thesystem; thepublic, throughwhose land thedistributionsystem isbuilt;andanyagencieswithwhichWestpowercomesintoregulatorycontact.

ElectroNetServices’assetmanagementteamhasresponsibilityfortheday-to-daymanagementofthecompanyanditsassets,andforcarryingoutcompanypolicies.Westpoweristhe“owner”oftheplan,whoisresponsibleforitscreationandforusingitasatoolforimprovingtheefficiencyandeffectivenessofmanagingWestpower’sassets.

Theinterestsofouremployeesareidentifiedthroughdirectdiscussionwiththemandtheirrepresentatives.Ouremployeesareinterestedin:

• Advancedknowledgeofworkrequirementssothattheycanplantheirlives;

• Asafenetworkandsafeworkingpracticessothattheyarenotharmed;


• Fairremuneration;

• Enjoyablework.


• Thehighprioritygiventoeliminatingormitigatinghazards;

• Advancedplanningofwork;

• Therecognitionthatourstaffhaveuniqueskills;

• Creatingapositiveworkenvironmentthatcreatesahighlevelofself-worth.

Contractors’interestsareidentifiedthroughdirectdiscussion.Currently,theyareinterestedinhaving:

• Asecureworkprogrammeknownsufficientlyinadvancethattheycanplantheirresourceallocation;

• Asafenetworkandsafeworkingpractices,sothattheirstaffarenotharmed;

• Aprofitableworkstream.


• Thehighprioritygiventoeliminatingormitigatinghazards;

• Advancedplanningofwork,includingcommitmenttoalong-termassetrenewalprogramme.

Thesecondarystakeholderinterestsareasfollows:

Auditors

• Systemsandprocessesmustbesuitabletomeetlegislationrequirements.

Government Agencies (this includes District and Regional Councils and Central Government).

• Processesareinplacetomeetcompliancerequirementsandreportingsystemsinplacetomeetdisclosurerequirements.

• DistrictCouncil interestsare identified throughdirectdiscussion.Currently, theyare interested inhavingsufficientinfrastructureavailablesothatgrowthintheirlocalcommunityisnothampered.

• The above interest is accommodated in the plan by the requirement that any customer-drivendevelopmentworkweundertakeproducesatleastourcostofcapital.

• RegionalCouncilinterestsareidentifiedmostlybycorrespondenceandwritteninformation.RegionalCouncilinterestsincludeprotectingtheenvironmentandemergencyresponse.

• Central government interests are identified mostly by correspondence, written information andlegislation.Centralgovernmentinterestsincludeensuringthatareliable,fairlypricedsupplyofelectricityisavailabletotheWestCoastregionandthatthenetworkissafe.

• TheinterestsofGovernmentagenciesarerecognisedthroughcomplianceandsubmissions.

Suppliers and Generators

Westpowerprovidesareliablenetworkthroughwhichtotransportenergy,sothatthenetworkhassufficientcapacitytoaccommodatetherequiredtransfersofenergy.ThechargesimposedinusingWestpower’snetworkareacceptableandthereisadequateaccesstoWestpower’snetwork.

Suppliersandgenerators’interestsareidentifiedthroughcommunicationanddirectdiscussion.Currently,thesegroupsareinterestedinprotectingtheirconnectedequipmentandtheelectricitysystemfromharmcausedbythenetworkandloadcustomerswhoareconnectedtotheWestpowernetwork.Westpowerisalsointerestedinreceivingrevenueandbeingchargedafairmarketpricefortransmissionservices.

INTRODUCTION 35

The above interests are recognised in the plan by the sums we have programmed for expenditure due toanticipatedgrowthindistributedgenerationandload.Asignificantproportionofthisistoensuretheprotectionofthegrid.

Transpower

Westpowerprovidesadequatemaintenancestandardstokeepthenetworkoperational.Thenetworkmustbereliable,andsufficientcommunicationshouldbemaintainedbetweenWestpowerandTranspower.

Transpower’s interestsare identifiedthroughcommunicationanddirectdiscussion. Currently,Transpower isinterestedinprotectionofitsgridandtheelectricitysystemfromharmcausedbygeneratorsandloadcustomerswhoareconnectedtotheWestpowernetwork.AnotherofTranspower’sinterestsisreceivingregulatedrevenuefromus.

The above interests are recognised in the plan by the sums we have programmed for expenditure due toanticipatedgrowthindistributedgenerationandload.Asignificantproportionofthisistoensuretheprotectionofthegrid.

Landowners

Issuesareidentifiedthroughdiscussionwiththeirrepresentatives(e.g.FederatedFarmers)andthepre-accessnotification process. Currently, they are interested in protecting areas of heritage value, protecting amenityvalue,havingtheirpropertytreatedwithrespect,protectingpropertyvaluesandhavinganelectricitysupplyatacompetitiveratewhichissuitablefortheactivitiesontheirland.Theseinterestsarerecogniseddirectlyandmanagedthroughstandardcustomerrelationshipapproaches.

Insurers

The interests of insurers are forWestpower to provide adequate risk management to meet the insurancerequirementsandtominimise riskswherepossible.These interestsaremetbyWestpowerhavingadequateinsurancesinplaceforidentifiedrisksandliabilitiestoemployees,assetsandthegeneralpublic.

Financial Institutions

Westpowershouldprovidesufficientfinancialperformancetocoverborrowingsandtomaintaintheircorporateidentitytoaconsistentstandard.TheseinterestsaremetbyWestpowerthroughreportingregularlyonfinancialperformanceandthroughregularaudits.

External Advisers

Theinterestsofexternaladvisorsincludecontinuityofwork,contractualrelationships(ifapplicable)andsafety.TheseinterestsaremetbyWestpowerthroughcommunicationwithrelevantpartiesasnecessary

Pressure Groups

Relevantinterestsincludepolicy,reliability,pricingandsafety.TheseinterestsaremetbyWestpowerthroughpubliclyissuedreports,andpressandmediareleases.

Press and Media

The interests of the Press and othermedia relate to news, public relations, alternative energy sources, theenvironment,informationchannelsandcrises.TheseinterestsaremetbyWestpowerthroughpubliclyissuedreports,andviapressandmediareleases.


2.1.7.2 ManagementofConflictingStakeholderInterests

Clearly,therewillbetimeswhentheindividualinterestsofvariousstakeholdersmaycreatepotentialconflicts,andWestpowertakesaconsultativeapproachbylisteningtotheconcernsofthepartiesinvolvedandtakingtheseintoaccountwhenmakingdecisions.

Theoverarchingdriversofprovidingasafeandreliablesupplyofelectricityatareasonablecost,whileensuringthat,whereverpossible,allstakeholdersaretreatedequitably, formaframeworkwithinwhichthebest-caseoutcomesaredetermined.Ofcourse,thiswillofteninvolvesomeformofcompromise,exceptwherehealthandsafetyissuesareconcerned.

WhereagoodcaseismadethatrequiresachangeintheAMP,thiscaneitherbereviewedduringtheyearifurgent,subjecttobudgetaryapprovalfromtheBoard,orincludedinthefollowingyear’sAMP.Insupportofthis,theassetmanagementdivisionmaintainsaregisterofrecommendedchangesthatare incorporatedintotheAMPeachyear.

Westpower’spolicy is thatnewconnections toWestpowernetwork shouldnotbe subsidisedby its existingcustomerbase,andthereforenewcustomersarechargedthefullcostofnewconnections.Thisistakenintoaccountwhendeterminingthebestsolutiontosupplyneworincreasedloads.

Communicationisthekeytoolusedtomanageresidualconflictbetweenstakeholders.Itisourexperiencethatwhenstakeholdershaveall the factsbefore them, theyarewilling toadopt thesolution that is for thebestoverallgood.Ourtaskistoensurethatstakeholdershavetherequiredlevelofinformation.

Examplesofhowconflictinginterestsaremanagedincludethefollowing:

1. Assetrenewal

OurshareholdersrequireinvestmenttoreturnWestpower’scostofcapital.Theyarenotwillingtolowercashreturnsreceivedinordertofundnetworkupgrades.Ontheotherhand,consumersareunwillingtomeethighprice increases.Bothgroupswantasustainablenetworkand improvements in reliability.Thisconflict ismetthroughatargetedrenewalsprogramme,whichensuresthatthenetworkdoesnotreceiveover-investment,andatargetedreliabilityprogrammetoensurethatreliabilitycontinuestoimprovewithoutasignificantincreaseinnetworkinvestment.Innovativepracticesalsoplayamajorpartinaligningtheseinterests.

2. Networkcapacitycharges

Historically,networkshavebasedchargesontransportedenergy,afixedcomponentand,perhaps,demand.Thecostoftransportingenergyalwayshasademandandfixedcomponent.Westpowerhaschangedthestructureofall linechargestobetterreflectcostsbyhavingseparatedemandanddedicatedassetcomponents.Inthemediumterm,energypassingthroughthemeterisusedtoestimatedemandusingacomplexalgorithm.Inthelong-term,itisproposedthatdemandmetersshallbeusedonallinstallations.

3. Contractorresourceconstraints

TheisolationoftheWestCoastmeansthatWestpowerisdirectlyreliantonthecapabilitiesandresourcesofitsmaincontractorforallworkontheassets.Attimes,thecontractormaybeover-committedduetootherworkwhenlargeexternalprojectsareunderway.ThisdichotomybetweenmaintainingWestpower’sassetstoahighstandardandmaximisingfinancialperformanceofthecontractorisresolvedthroughcarefulsupervisionoftheannualAMPprogressand regulardiscussionof forwardwork commitmentsat themanagement team level,includingstafffromboththeassetmanagementandoperationdivisions.Moreover,theChiefExecutiveretainsthepowertodirectthatprioritybegiventoassetworkasrequired,asaresultofhis/herdualroleofmanagingbothWestpowerandthecontractingsubsidiary,ElectroNetServices.

4. Safetyimprovements

ExperiencehasshownthatallofWestpower’sstakeholderswantasafenetwork.Determiningwhatissafeorunsafeisnotblackandwhite.Thedefinitionofwhatissafeandunsafeisconstantlyevolvingastimegoeson.Aseventsoccurandexpectationsadvance,safetycodesarerepeatedlyrewrittenandredrafted.Thismeansthatequipmentthatwasconsideredsafewheninstalled,isovertime,eclipsedbychangedandimprovedequipment.

INTRODUCTION 37

Whengrowthoccursinanetwork,equipmentisconstantlyreplacedandupdated.IntheWestpowernetwork,muchoftheoldlegacyequipmenthasnotbeenreplacedaspartofthenaturalgrowthcycle.Thisleadstoconflictbetween funding safety improvementworkandother renewalandCapitalExpenditure (CAPEX)work,alongwithdecisionsonthedefinitionofsafeandunsafe.Fortunately,muchoftherenewalassociatedwithsafetyalsoimprovessecurity,reliabilityandgeneralnetworkcapacity.Availableresourcestendtodominatetheconflictastohowmuchcanbedoneatonce.Theconflictbetweenwhatissafeandunsafeisbasedon:

• Observationsofobviousproblems;

• Industryaccidentreports;

• ThevariousActs,RegulationsandCodesthatcontroltheindustry;

• Theapplicationofongoingprinciplestohowequipmentoperatesandtherisksthatcomeaboutwhenthingsgowrong;

• Experiencefrominvestigatingandbeinginvolvedwithvariousindustryincidents.

5. Conflictbetweencustomerinterestsascustomersandshareholders

As shareholders, customersgeta return. Somecustomerswouldprefer lowerupfront chargesor to see themoneyreinvestedinthenetwork.WebelievethatthisistheresponsibilityoftheTrustees,whoareelectedbyourcustomers,toresolvethisconflictbyconsultationandadvisethecompanythroughtheSCIprocess.

2.2 Asset Ownership Justification

2.2.1 WestpowerYesterday

Inthelate1800stotheearly1900s,privatepowergeneratingschemeswerebeingbuiltthroughouttheWestCoast region, mainly to supply gold claims. Reefton was the first public supply connected in the SouthernHemisphereinDecember1887.OthersupplieswereatDillmanstownandKaniereintheHokitikaarea.

2.2.2 WestpowerToday

Westpower isacombinationofanumberof theearlypowercompaniesandgeneratorson theWestCoast.In 1972, theWestCoast Electric PowerBoardwas formedby the amalgamationof theAmethyst,Grey andWestlandElectricPowerBoards.

2.2.3 WestpowerTomorrow

AMPsmustaddressgrowth.ProjectionsfortheWestCoastarecontinuallyreviewedbyWestpowertoensurethatthesubtransmissionanddistributionnetworkisadequateforthedemand.

2.3 Justification of Assets

The sub transmissionanddistribution componentsof theWestpowernetworkhaveevolvedover anumberofyears,withtheincreaseofcustomerdemandintheregionbeingtheprimarydriver.ThelargeareaoftheWestCoastforwhichWestpowerisresponsible,coupledwiththediversegeologyencountered,hasresultedinstrategicallyplacedassetsthroughouttheregion,thatgenerallyprovideareliablesupplyandofferscalabilityforthefuture.

ManyofWestpower’slinescanbeverylongandtraverseextremelyruggedterrain,oftentosupplyverylightlypopulatedareas. Toensure that supplymeets customers’ requirements, these lineshavebeendesigned toreducelinelosses,andvoltagesupporthasbeenstrategicallyemployed.

Thecontinualloadincreasesin“remote”areassuchastheGlaciertownships(FoxandFranz),andthegrowthinindustrialloadssuchasmininganddairyfarmingareconsiderationswhenasubtransmissionordistributionassetisrefurbished,withrefurbishmentcostssometimesbeingsharedwithlargercommercialentities.


Thelast10to15yearshaveseenapushtoensurethatassetsareuptothetaskexpected,withanextensiverenewalandreplacementprogrammeupgradingthevastmajorityofsubtransmissionanddistributionassets.

2.3.1 JustificationofGXPs

Connection/SupplyPoints

Westpowerownsthreedistinctclassesofsubtransmissionassetsrunningat110kV,66kVand33kV,emanatingfromsevenGXPpoints,withanadditionalGXPatOtiraprovidingan11kVsupply. TheprimaryGXPscanbefoundatDobson(33kV),Greymouth(66kV),Hokitika(66kV),Kumara(66kV),Reefton(110kV)andAtarau(110kV).DetailsofthecapacityandloadprofileforeachoftheGXPscanbeseeninTable3.4inSection3.

ThejustificationsforeachoftheseGXPsaredescribedbelow:

2.3.1.1 DobsonGXP

The Dobson 33 kV supply point provides capacity tosupply the Westpower network northwards to NgahereSubstation, the main supply point for the Ngahere GoldDredgingoperationandtheRoaCoalMine.EastofDobsonis the Arnold substation, which supplies the CMP KokiriMeatworksandalargefarmingarea,andalsoallowsfortheconnectionof Trustpower’s 3MWArnold generation. Thenorthwestern section of theDobsonGXP connects to theRapahoe substation, which supplies Solid Energy’s SpringCreekMineandtheCoastRoadarea.ThesesubstationsaresuppliedbytheDobsonGXP’sthree33kVfeeders.

TheDobsonGXPalsoconsistsoftwo11kVfeedersprovidingsupply to Dobson, Kaiata, Taylorville, Stillwater and CoalCreek.

ThisGXPwastheprimaryGXPfortheGreymoutharea,butwassituatedtoofarfromGreymouthtosupplythegrowingloadinthatarea;theGreymouthGXPwasthereforeconstructedinthelate1970s.

ThisGXPisessentialforsecurityofsupplyintheaforementionedareasaswellassupportingtheGreymouthGXPfromtimetotime.

2.3.1.2 GreymouthGXP

Supplying the greater Greymouth distribution networkfrom seven 11 kV feeders, the Greymouth 66 kV GXP issupplied primarily from theGYM-KUM66 kV cct and theTranspower’sDOB-GYM66kVcct.ThisGXP isrequiredtosupplythelargestdomesticloadontheWestCoast,aswellas significant industrial loads such as engineering, fishingandtimbermilling.

As theGreymouth loadhasgrownsignificantly in the last30 years, an independent GXP is required to satisfy thedemandpresentinthisarea.

Figure2.8-GreymouthGXP

Figure2.7-DobsonGXP

INTRODUCTION 39

2.3.1.3 HokitikaGXP

AswellassupplyingthegreaterHokitikadomesticload, there are large number of industrial, dairyfarmingand tourism-driven loadsemanating fromtheHokitikaGXP.IncludedintheseistheWestlandMilk Products Hokitika processing factory. ThisGXPisgeographicallythelargestintheWestpowerarea,supplyingtheSouthWestlandareatoParinga(some200kmaway)andtheflatsoftheKokatahi-Kowhitirangiarea.TheHokitikaGXPconsistsoften11kV feedersandone33kV feeder that suppliesSouthWestland.

Constructed in 2002, the Hokitika GXP wascommissioned due to the increasing demand intheareaandthedecommissioningofTranspower’sArahurasubstation.Withthisinmind,coupledwiththedistancebetweenGXPs, theHokitikaGXPwasdeemedtobeessential.

2.3.1.4 KumaraGXP

The Kumara GXP is mainly required to provide aGrid InjectionPoint (GIP) forTrustpower’s10MWKumara hydro scheme, but also supplies localload, via two 11 kV feeders, in the area betweenGladstoneinthenorthtoJacksonsintheeastandtoDuffers in the south.Apart from the significantgeneration, the load type is mainly farming andrural residential, although the IPL Plywoodmill atGladstonedemandssignificantload.

ThecloseproximityofTrustpower’shydroschemeis theprimary reason that theKumaraGXPexists.Without this injection, the Kumara area couldpossiblybesuppliedfromanalternateGXP.

2.3.1.5 ReeftonGXP

TheReeftonGXPsuppliesloadviatwo11kVfeedersbetweenLyell inthenorth,Berlins intheeastandBlackwatertothesouth.Theloadischaracterisedmainlybydairyfarminganddomesticload,althoughthere is somemining and commercial load in thetownofReefton.

TheReeftonGXPalsosuppliesBlackwatersubstationto the south and theOceanaGoldGlobemine totheeastviatwo33kVfeeders.

The distance from an alternate GXP deems theReeftonGXPnecessary,and thisGXP is integral insupplyingWestpower’snorthernnetwork.

Figure2.10-KumaraGXP

Figure2.11-ReeftonGXP

Figure2.9-HokitikaGXP


2.3.1.6 AtarauGXP

TheAtarauGXP is primarily to supply thePRCCCompany (PRCC)miningoperation,withone110kV feedersupplyingLogburnsubstation.

PRCC’sloadrequirementsaresignificantandcouldnotbesuppliedwithoutthisGXP.

TheAtarau switching station is ownedby Transpower,withother connectionassets, including transformers,beingsuppliedbyWestpower.

2.3.1.7 OtiraGXP

TheloadatOtiraistotallyisolatedfromotherGXPs,and,apartfromasmallhotelandafewhouses,themajorityoftheloadconsistsofthefanmotorsfortheOtirarailtunnel.Thisloadissuppliedfromasingle11kVfeeder.

AlthoughtheloadinOtiraisrelativelysmall,theisolationoftheareafromotherpartsofthedistributionnetworkmeansthattheOtiraGXPiscriticaltosupplythearea.ThisincludesthecriticaltunnelloadneededtosupportthecoalexporttradefromSolidEnergy’sWestCoastoperations,withnoalternativesourcebeingavailable.

TheOtirasubstationisownedbyTranspower.AnupgradeofthisGXPwascompletedin2010/11.

InadditiontothesevenGXPslistedabove,Westpowerhasafurther14zonesubstations.

2.3.2 JustificationofZoneSubstationAssets

The justification foreachof thesezonesubstations isasdescribedbelow:

2.3.2.1 BlackwaterZoneSubstation

CommissionedinDecember2009,thetwo11kVfeedersatBlackwaterzone substation primarily supply the PRCC coal load-out facility atIkamatuaaswellastheareafromMawheraitidowntotheAhauraPlains,whichpredominantlyincludesdairyfarming.TheBlackwaterzonesubstationhasbeenbuiltdue to the increaseddemand fromthecoalload-outfacility,whichcouldnotbesuppliedfromeithertheReeftonorNgahere11kVnetworks.

Anolderrefurbishedtransformerofoptimumcapacitywasusedforthisprojecttoallowforfuturegrowthwhilebeingcost-effective.

TheBlackwatersubstationcanalsoprovidebackupsupplytoNgahereandReefton,whenrequiredformaintenanceandfaults.

2.3.2.2 NgahereZoneSubstation

Thetwo11kVfeedersatNgaherezonesubstationsupplyanareafromAhaurainthenorth,downtheGreyValleyincludingRoaandBlackball,andinlandeastasfarasNelsonCreek.NgaherezonesubstationprimarilysuppliestheNgaheregolddredgeoperationandtheRoaCoalMine,aswellastheNgahereprocessingmill,NelsonCreekabattoirsandnumerousdairyfarms.TheNgaherezonesubstationisideallylocatedduetoitsproximitytoitsprimaryloads.

Figure2.12-BlackwaterZone

INTRODUCTION 41

2.3.2.3 ArnoldZoneSubstation

Situated next to Trustpower’s Arnold power station, thetwo 11 kV feeders at Arnold zone substation supply theCMPKokiriMeatworksandalargefarmingareaincludingseveralLandcorpdairyfarms,coveringanareafromKokiriinthewest,fromMoanatownshiptoInchbonnieintheeastandasfarasHaupiritothenorth.ArnoldzonesubstationalsoprovidesTrustpoweraconnectionfortheirgeneration(3MW)intoWestpower’snetwork.Duetofurthergrowthindairyfarming,especiallyLandcorp’sfarms,developmentinMoanatownshipandtheabilitytoprovideaconnectionpoint for Trustpower’s Generation, the Arnold zonesubstationisanecessaryasset.

2.3.2.4 RapahoeZoneSubstation

CoveringanareaalongtheCoastRoadareatoPunakaikiinthenorthdowntoCoalCreek inthesouth, includingthe townships of Barrytown, Runanga, Rapahoe andDunollie, the two 11 kV feeders at Rapahoe zonesubstation’s primary supply is to Solid Energy’s SpringCreek Mine at Dunollie and the abovementionedtownships. Thedistanceandhigh costs associatedwithsupplyingtheCoastRoadareafromDobsonviaan11kVlineandthedemandatSpringCreekdeemtheRapahoezonesubstationtobecriticaltosupplythisarea.

2.3.2.5 RossZoneSubstation

TheRosszonesubstationwasbuiltin1995duetothe66kVlinebetweenArahuraandHariharibeingchangedtoa33kVline.PrimarilysupplyingBirchfield’sRossminingoperationandRosstownship,thetwo11kVfeedersalsosupplyanumberof farms inthearea,coveringanareathat runs from just south of Ruatapu, including TotaraValley,as farsouthtoMikonui.Becauseof thedistanceandhigh costs associatedwith supplying theRoss areafromHokitika via an 11 kV line, the Ross Substation isideallylocated.

2.3.2.6 WaitahaZoneSubstation

Supplying primarily a farming area, the one 11 kV feeder atWaitaha Zone Substation covers the areas ofFergusonsBush,Kakapotahi,WaitahaValleyandPukekura,whichincludesthePukekuraHotel,theWildernessTouristCentreandKordia’sradiosite.LikethezonesubstationatRoss,theWaitahazonesubstationwasbuiltin1995.TheremotenessandhighcostsassociatedwithsupplyingtheWaitahaareafromRossorHarihariviaan11kVlinemakestheWaitahazonesubstationnecessaryatitscurrentlocation.

Figure2.13-ArnoldZoneSubstation

Figure2.14-RapahoeZoneSubstation


2.3.2.7 HarihariZoneSubstation

The Harihari zone substation was built in 1995 due tothe decommissioning of the Transpower switchyard onWanganuiFlatRoad.Supplyingprimarilyafarmingarea,the two 11 kV feeders at the Harihari zone substationcoveranareafromLakeIantheinthenorthtothePoeruaValley in the south, including the township ofHarihari.Due to the remoteness and high costs associatedwithsupplying theHarihari area fromWaitaha orWhataroaviaan11kVline,theHariharizonesubstationisrequired.

2.3.2.8 WhataroaZoneSubstation

Also supplying primarily a farming area, the one 11 kVfeederattheWhataroazonesubstationcoverstheareasofTeTaho,WhataroaFlatandWhataroatownship.Theremoteness and high costs associated with supplyingtheWhataroaarea fromHarihari via an11kV lineandisolation requirements for faults/maintenance on the33 kV circuit between Harihari andWahapo make theWhataroazonesubstationnecessary.

2.3.2.9 WahapoZoneSubstation

The Wahapo zone substation is located next toTrustpower’sWahapopowerstation.Itsone11kVfeederprimarilysuppliestheOkaritoareaandallowsTrustpowertohaveaconnectionfortheir3MWWahapogeneratorintoWestpower’snetwork.

2.3.2.10FranzJosefZoneSubstation

PrimarilysupplyingthetourismindustryintheFranzJoseftownshipandthefarmingindustryinthearea,thetwo11kVfeedersattheFranzJosefzonesubstationcoveranareafromWaihoFlatinthesouthtoLakeMapourikainthenorth.FranzJosefZoneSubstationisnecessarytocaterfortheexpansionoftheFranzJoseftownshipduethegrowthinthetourismindustryintheGlacierregion.

2.3.2.11FoxZoneSubstation

TheFox33kVzonesubstationwasbuilt in2003duetotheexpansionoftheTourismIndustry inFoxGlacierTownship.Theone11kVfeederattheFoxzonesubstationcoversalargeareafromtheFoxTownshipandCookFlatsinthenorthtoLakeParingainthesouth.LikethatofFranzJosef,FoxzonesubstationprimarilysuppliesthetourismindustryintheFoxGlaciertownshipandthefarmingindustryinthearea.Withthetourismindustrystillexpanding,thevastnessandremotenessoftheareadeemstheFoxzonesubstationtobenecessary.

Figure2.16-WhataroaZoneSubstation

Figure2.15-HarihariZoneSubstation

INTRODUCTION 43

2.3.2.12GlobeZoneSubstation

Thethree11kVfeedersandone6.6kVfeederattheGlobezonesubstationareforsupplyingtheOceanaGlobe Gold Mining operation outside of Reefton.DuetothedemandoftheOceanaGlobeGoldMineand the distance from Reefton, the Globe zonesubstationiscritical.

2.3.2.13LogburnZoneSubstation

Thethree11kVfeedersatLogburnzonesubstationprimarily supply the coal processing plant, bath-house and workshop for the PRCC, and alsosupplya33kVsupplytothePikezonesubstation.As well, Logburn zone substation also covers thepredominantly dairy farming area of Atarau fromCraigeburn toMoonlight. The demand fromPRCCandtheexpandingdairyfarmingintheGreyValleyarea deems the Logburn Zone Substation to benecessary.

2.3.2.14PikeZoneSubstation

Theseven11kVfeedersatthePikezonesubstationare for the supply associated with PRCC’sMiningoperations. The underground operations of themine and the associated surface operations PRCCrequired the substation to be built at its currentlocation. Due to the recent incident at the PRCCmine, a review of this substation’s requirementsmayberequiredinthecomingyear.

2.3.2.15 SpringCreekZoneSubstation

The Spring Creek 33 kV substation supplies SolidEnergy’scoalminingoperationsatSpringCreek.Thesubstationhastwo6.6kVandone3.3kVfeeders.Thesubstation issuppliedbya33kV feeder fromDobsonGXP.

TheSpringCreekzonesubstationisownedbySolidEnergy.

Figure2.18-GlobeZoneSubstation

Figure2.17-LogburnZoneSubstation

Figure2.19-PikeZoneSubstation


2.3.3 Justificationof110kVSub-transmissionLines



2.3.6 JustificationofDistributionandReticulationLines

Theselineshavebeeninstalledhistoricallytosupplyconsumers,bothasindividualsandgroups,andthegenericjustificationiscustomerdemand.

2.4 Asset Management Drivers

The factors that drive assetmanagement activities and their relationship toWestpower’s performance arederivedfromtheexternalperformancerequiredofWestpowerbyitscustomers,workers(includingcontractors),shareholdersandthepublic.

Thedriversforthisplanareasfollows(thesearecoveredinmoredetailinSection4-LevelsofService):

• Safety,

• Customerservice,

• Capacity(i.e.adequacyofservice),

2.20 Justification of 110 kV Lines Sub-transmission

Asset Use Length Optimum Justified

ATU-LGN SuppliestheLogburnSubstationfromTranspower’sAtarauGXP.Subsequentlysup-pliesthePikeRiverCoalMine 9km Yes Yes



GYM-KUM SinglecctsuppliesGreymouthGXP.WestpowerownedTranspoweroperated.RequiredtoprovideN-1securitytotheGreymoutharea. 23km Yes Yes

KUM-KAW Doublecct.OnecctsuppliesKumaraGXPfromTranspower,theotherHKKGXPfromKumara.RequiredtosupplyHokitikasouthtoParinga 11km Yes Yes

HKK-TMR Doublecct.OnecctsuppliesHKKfromTranspower,theotherHKKfromKumaraGXP.RequiredtosupplyHokitikasouthtoParinga 8km Yes Yes



HKK-HHI SpurlinefromHokitikatoHarihari.VitalsupplytoSouthWestlandwhichwillbeupgradedto66kV 69km Yes.Tobeupgradedto

66kV Yes

HHI-WAT SpurlineHariharitoWhataroa.SuppliesWhataroatownship-south 29km Yes Yes

WAT-FRZ Spurline–WhataroatoFranzJosef.SuppliesFranzJoseftownship–south.IsusedforinjectionfromTrustpower’sWahapoHydroScheme 28km Yes Yes

FRZ-FOX Spurline–FranzJoseftoFoxGlacier.SuppliesFoxGlaciertownship–south.Upgradedto33kVin2003 20km Yes Yes

ALD-DOBArnoldSubstationtoDobsonSubstation.UsedprimarilyforinjectionofTrustpower’sArnoldHydroScheme.AlsosuppliestheRotomanu,

Moana,Haupiriarea.17km Yes Yes

DOB-RFN DobsonSubstationtoReeftonSubstation 71km Yes Yes

DOB-RAP Spurline-DobsonSubstationtoRapahoeSubstation.SuppliesSpringCreekMineandRapahoeSubstation.EssentialforCoastRoadsupply 14km Yes Yes

LGN-PIKSpurline–LogburnRdSubtoPikeRiverMinesubstation.SuppliesthePikeRiverCoalMine.Significantenvironmentalfactorsjustified

theuseofHendrixinsulatedcable.6.5km Yes Yes

INTRODUCTION 45

• Reliability(i.e.continuityofservice),

• Economicefficiency,

• Environmentalresponsibility,

• Corporateprofile,

• Legislationandcompliance.

2.5 Asset Management Linkage with Westpower Performance

Figure2.23showstherelationshipbetweenassetmanagementandWestpower’sperformance.

Theserelationshipsserveasaframeworkforfocussingonthereasonswhyparticularassetmanagementactivitiesarerequired.

Ultimately, Westpower’s performance is judged externally and the drivers outlined in Section 2.4 are theparametersbywhichthisperformanceismeasured.

Figure2.23PerformanceLinkages


DifferentassetmanagementandoperationalresponsescanbeusedtomeetWestpower’sexternalperformancerequirements.Thesemay includemaintenanceto improvetheconditionoftheasset,developmentto installassetsinanewconfiguration,enhancementstotheexistingsystemorchangestothewayinwhichtheassetsareoperated.Effectivemanagementofthebusinessinvolvesselectingthemostappropriateassetmanagementoroperationalresponses,asproposedinthisplan.

2.6 Plan Structure and Approach

This plan uses a consistent set of defined activities and asset types to categorise work programmes andtheir associatedexpenditure. Budgeting andfinancial reportingwithinWestpower allows actual programmeachievementandexpenditureoutcomestobecomparedwiththeplan.Consistentuseofthisframeworkwillfacilitatecomparisonsovertime.

It should be noted that the activity and asset definitions are independent of accounting classifications ofexpenditure (i.e.betweenmaintenanceand capital expenditure). Therefore trends,overtimeshouldnotbealteredbyanychangesintheapplicationofaccountingpoliciesregardingthetreatmentofexpenditure.However,itshouldalsobenotedthat,underthecurrentapplicationofaccountingpolicies,allactivitiesareclassifiedaseitherentirelyoperatingexpenditure(OPEX)orentirelyCAPEX.

Similarly,theactivityandassettypedefinitionsarealsoindependentofWestpower’sorganisationalstructureandresponsibilities,althoughtheyarecloselyalignedwiththepresentstructure.Inthelongrun,adherencetothedefinitionswillensurethattheplanremainsmeaningfulinspiteofanychangesinorganisationalstructureorresponsibilities.

TheassetandactivityplanningcategoriesaredefinedinAppendixA.It isobviousthatnotallassettypeandactivitycombinationsareused.Inaddition,maintenanceactivitiescangenerallybeplannedatthedetailedassetlevel (e.g. servicingof transformers, circuit breakers),whereasdevelopmentprojects or programmes,whichtypically involve a combinationof different asset types (e.g. lines, transformers, circuit breakers, protection,communicationsandnetworkmanagement)arekeptintactratherthanattemptingtoallocatetheexpenditureagainstthecomponentassettypes.

A furtherdefinitionaldistinctionbetweenprojectsandprogrammes ismadethroughout thisplan.Theword“programme”isusedtodefineagenericactivitywithagenericjustification,butwhichmayapplyatanumberofdifferentsites.Replacementofdefectiveinsulators,fittingvibrationdamperstolinesandupgradingconnectorsarethereforeclassedasprogrammes.Ontheotherhand,“projects”aresite(orasset)specific,e.g.addingasecondcircuittoaparticularlineorupgradingaparticulartransformerbank.

2.7 Core and Advanced Asset Management

2.7.1 OutlineofCoretoAdvancedApproach

WestpoweriswelladvancedinaligningitsassetmanagementsystemtotheBritishStandardPAS-55:2008,AssetManagement.

PAS-55definesthesystematicandcoordinatedactivitiesandpracticesthroughwhichWestpoweroptimallyandsustainablymanagesitsassetsandassetsystems,andourapproachtoperformance,risksandexpenditureoverthelifecycleoftheassetsforthepurposeofachievingWestpower’sstrategicplan.

Goodassetmanagementconsidersandoptimisestheconflictingprioritiesofassetutilisationvs.assetcare,ofshort-termperformanceopportunitiesversus long-termsustainability,andcapital investmentvs. subsequentoperatingcosts,risksandperformance.

“Lifecycle”assetmanagement ismore thansimply theconsiderationof capitalandoperatingcostsover theasset’slife.Trulyoptimised,whole-lifeassetmanagementincludesriskexposureandperformanceattributes,andconsiderstheeconomiclifeasaresultofanoptimisationprocess.

INTRODUCTION 47

2.7.2 LimitationsofthisAMP

ThisAMPoutlinesWestpower’sintendedactivitiesoverthenexttenyearsbutshouldnotberelieduponasanyformofguaranteethatsuchactionswilloccurwithinthetimeframesstated.Peoplewantingcertaintyofanyactionsfordevelopmentshouldcontactthecompanyforfurtherinformation.

ThisAMPdoesnotcover:

• DetailsofWestpower’snetworkpricingderivationandapplication(theseareavailableonourwebsite);

• Vehicles,non-networkrelatedland,buildings,furnitureorgeneralofficecomputerequipment;

• Theoverheadcostsofoperatingthenetworkcontrolcentreandotherindirectoverheadcosts.

2.8 Asset Management Systems and Processes

Several systems and processes are used in Westpower’s assetmanagementtofacilitateroutinemaintenanceandinspections,planningfornetworkdevelopmentandmeasuringnetworkperformance.

Network data collection and reporting is performed and representedby GIS (spatially) and Maximo (the asset infrastructure framework).Although they are independent, GIS and Maximo share location andassetdataviaaseriesofsynchronisationsandsystemviews.Thesedataareusedtoevaluaterisk,informmanagersandprovidetheframeworkforpreventativemaintenance,allofwhichimproveoverallmanagementoftheWestpowernetwork.

These systems,and theaccurateandtimely information theyprovide,support the cost/benefit effect of maintenance. This results in bettermaintenanceoptimisationandpredictionsoflong-termeffects.

Thissectionoutlinesthefollowingsystemsandprocess:

• Newconnections,

• Preventativemaintenance,

• Asset maintenance and inspections (condition assessmentprogramme),

• Networkdevelopment,

• Networkperformance.

2.8.1 NewConnections

Workflow is an integral part of Westpower’s asset works management system and enforces Westpower’sbusinessprocesses.Figure2.25describes theworkflowused fornewconnections. Thekeyelementsof theworkflowincludenotificationtothecustomerandelectriciansotheyareinformed,andtheacknowledgementfromtheretailerensuringthatallcustomershavearetailercontractbeforetheyarelivened.

Allnewconnectionrequestsaremaintainedontheassetmanagementsystem,andsupportingdocumentationshowingconnectionpoints,connectionagreements,andliveningsheetsareattachedtotheserequests.

Figure2.24-FlowchartforDevelopmentofAMP


2.8.2 PreventativeMaintenance

WestpowerhasemployedPreventativeMaintenance(PM)planswhichareperformedregularly,basedonelapsedtimeormeterreadings.PMsarebeingdevelopedforeachasset/locationthatisactivewithinthenetworkandwhereconditionassessmentdoesnotapply.

The time-lapsed PMs are based on the manufacturer’s specifications/recommendations or engineeringassessments subject to thenatureof theequipment, its importance to thenetworkand theenvironmentalconditionsitmaybeexposedto.

AsthesePMsaredeveloped,jobplansareattachedthatdictatethenatureofmaintenancerequiredonatask-by-taskbasis.Whererelevant,thetasksequenceisalsodeterminedonthejobplan.Anyphotosormanufacturer’smanualsoftheequipmentorlocationarealsoattachedtothePM.

Whereappropriate,routesareappliedtoPMswhichorganiseworkpackagesintoalogicalandefficientorder.

Inadditiontoelapsedtimeormeterreading-basedpreventativemaintenanceinitiation,Westpowerisoptimisingoutagesandcoordinatingmaintenanceduringtheseperiods.

2.8.3 ConditionAssessmentProgramme

Fielddatacollection initiatives, in conjunctionwithworkauditprocesses,willensure thataccuratedataarecollectedinatimelyfashion,which,inturn,willinstilconfidenceinreportinghistoricalassetdata.

Figure2.25ProcessforNewConnections

INTRODUCTION 49

Figure2.26-ConditionAssessmentProcess

FIELD DATA

NEW DATA KEYED

AUTOMATED PROCESS

DATA ANALYSIS

YES NO

DATA ENTERED USING PORTABLE DEVICE

PROCESS FOR CONDITION ASSESSMENT OF

ASSETS

IDENTIFIED REQUIRED ASSESSMENT


Thefirst stageof thedata collectionprogrammewas theupgradeof the conditionassessmentprogramme,which provides direct integration of theArcPad field data collection systemwith theArcSDE database. ThisinformationisthenpassedtoMaximoonanightlyschedule.Assetsareinspectedonatleastfive-yearlyintervals,andchangesarerecordedoncompletionofanyworkcarriedout.Thespatialandaspatialdatacollectedprovideanaccuratereflectionofthenetworkatanyonetime.

Auditscarriedoutatworkcompletionassistwiththeclosingoffoftheprocess.

Theprocessesoutlinedabovehavebeenactivatedandareprovingtobeverysuccessful.

Processeshavebeeninitiatedtoensureallassetsarerecorded.ThisfinancialyearwillseethecollectionofbothspatialandaspatialdatapertainingtoLVpillarandlinkboxes.Itisenvisagedthatallassets,includingLVlineand,willberecordedwithintwoyears.ThiswillenablemoreaccuratetrackingofworkhistoryandwillalignwiththeMaximohierarchy.

2.8.3.1 WestpowerConditionAssessmentSpecification

ToenableWestpower to assess the conditionof its network accurately, a conditionassessmentprogrammehasbeen initiated.Thisprogrammeinvolvesthecollectionofrelevantdataonprimarily linesandassociatedequipment.Thisdataarethenused,viaGIS,toforecastrequiredmaintenanceandcapitalworks,andalsotoidentifyareaswhichmayposehealthandsafetyrisks.

Collection is performed usingHewlett-Packard Ipaq hand-held and notebook computers, completewith theEnvironmentalSystemsResearchInstitute’s(ESRI)ArcPadsoftware,whicheliminatestheneedformanualdataentryintotheGIS.

Twentypercentofeachline(feeder)isassessedinayear,allowingthetotalnetworktobecompletedinafive-yearcycle.

Networkcomponentstobeassessedwillbedividedintocategories,namely:

• Poles,

• Pillarboxes,

• Linkboxes

• Crossarms,

• Fittings(bracebars,insulators,shackles,polesteps,LVfusesetc.),

• Stays,

• Disconnectors,

• Transformers,

• Drop-outfusesandlightningarrestors,

• Earthingsystems,

• LVConductors,

• HVconductors,

• CablesLV,

• CablesHV,

• Other(reclosers,sectionalisers,capacitors,etc.),

• Vegetation.

Allcatagoriesareassessedusingthesameterminologyasfollows:

INTRODUCTION 51

Excellent

Componentisnearnew,lessthantwoyearsold,and/orstillinexcellentcondition;

Good

Componentstillhasgreaterthanaten-yearlifeexpectancyandisgenerallyingoodcondition;

Fair

Componenthasalessthanten-yearlifeexpectancy,butwilllastlongerthanfiveyears;

Poor

Componentcouldlastuptofiveyearsbutisgenerallyinpoorcondition;

Needs replacing

Componentisconsideredcondemnedbutwilllastuptotwoyears;

Red tagged

Componentisinurgentneedofreplacement,andposesahealthandsafetyrisk.

2.8.3.2 Methodology

Theprocessforeachcomponentwillbecompletedasdescribedbelow.

Pillar boxes

Allpillarboxesshallbethoroughlyinspectedandearthresistancetestscarriedout.Theconditionoffuses,cablesandtheboxshallalsoberecorded.

Poles

Allwoodenpolesshallbethoroughlyinspectedbelowground(to600mm).Astandardprobetestshallbecarriedout,alongwithahammertest.Anyknot-holesorsplitsabovegroundshallbeprobedandassessedaccordingly.

Allpolesshallhaveadetailedvisualinspectionperformed.Thisincludestherecordingofanyspallingorcrackingfoundonconcretepoles.

Crossarms

All crossarms shall have a detailed visual inspection performed. Any suspect LV or service crossarms shallbeprobedandassessedaccordingly.AnysuspectHVorsubtransmissioncrossarmsshallbenoted for futureinspection.

Fittings

Fittings,suchasbracebars,insulators,shackles,polesteps,LVfuses,boltsetc.,aretobeassessedcollectivelyusingadetailedvisualinspection.Theworst-caseconditionoffittingsshallberecorded.Ifanyfittingisassessedas‘poor’or‘needsreplacing’,notesdescribingrelevantdetailsofthefittingshallberecorded.

Stays

Theconditionofstaysandtheirassociatedfittingsaretobeassessedcollectivelyusingadetailedvisualinspection.Thiswillincludetheconditionofstaywire,stayinsulators,staydead-end,hoses,eyeboltsetc.Theworst-caseconditionofstaysandtheirfittingsshallberecorded.


Transformers

Transformersshallhaveadetailedvisualinspectionperformed,includingchecksonoillevels,crackedbushings,deteriorationofgasketsandanysignsofoildischarge.

Dropout Fuses and Lightning Arrestors

Dropout fusesand lightningarrestors shallhaveadetailed inspectionperformed,with their condition tobeassessedcollectively.Theworst-caseconditionofdropoutfusesandlightningarrestorsshallberecorded.

Earthing System

Theearthingsystemfortransformers,disconnectorsetc.shallbeassessedbymeansofadetailedvisualinspection.Onlyexposedcomponentsoftheearthingsystemneedtobeinspected,withtheworst-caseconditionoftheearthingsystembeingrecorded.

LV Conductors and HV Conductors

Generalconditionofoverheadconductorsshallberecorded.Conductorsshallbeassessedbyvoltage.Theworst-caseconditionoftheconductorsshallberecordedinthecaseofmultipleconductorsofthesamevoltage.

LV Cables and HV Cables

Generalconditionofundergroundcablesshallberecorded.Onlyexposedcomponentsofundergroundcablesneedtobeinspected,withtheworst-caseconditionofthecablesbeingrecordedinthecaseofmultiplecablesofthesamevoltage.

Vegetation

While assessing the conditionofWestpower’s network, the assessor shall note any vegetation thatmaybeencroachingtheline,oranyaccesstoequipmentthatmaybehinderedbyexcessivevegetation.

General Comments

TheassessorwillberequiredtonoteanygeneralcommentsthatcouldprovideinformationtoassisttheoverallsecurityofWestpower’snetwork.

Work Required

Anymaintenanceworkidentifiedshouldberecordedintheworkrequiredtextbox.Photosmustbetakenwherework is requiredand thenumber recorded in thephoto IDbox.Allwork requireddescriptionsshouldbeasdetailedaspossible,withadescriptionofthedefectandrecommendedactions.AnelectroniccopyofallphotosmustbesuppliedtotheassetmanagementdivisioninGreymouthoncompletionoftheassessment.

FielddataarethenuploadedintotheSpatialDatabaseEngine(SDE).Allconditioncodesareupdatedinstantlyasthesedataareuploaded,changingthestatusoftheasset’slastconditionanddateofassessment.AllworkrequiredisthenseparatedandanalysedusingArcGIS,andworkordersraisedwhereneeded.

These data can now be audited for analysis and further assessment when needed. Figure 2.26 shows theconditionassessmentprocess.

2.8.3.3 ConditionAssessmentDataRetrieval

AllassetdatacollectedinthefieldareuploadedtotheGISfromthehand-helddeviceupdatingcertainfieldsandtablesinthedatabase.Theconditionassessmentdateisalsoupdatedsotheseassetscanbeassessedagainwithinfiveyears.

INTRODUCTION 53

Work Required Table

Theworkrequiredtableuploadedfromthehand-helddeviceissplitintotwocategories:urgentandnon-urgent.

Urgentworkisgroupedintoareas.Aworkorderisthengeneratedforthisarea,includinganyassetsmarkedasneedingreplacementorredtaggedintheconditionattributeoftheassetdata.Anyassetthatrequiresinstantactionwillhaveaseparateworkorderraisedinordertorectifythisissueassoonaspossible.

Non-urgentwork isalsogroupedintoareasand issetasideforactionduringplannedoutagesorwhentimeallows.

Thedataretainedinthistablealsoenablestheassetteamtodesignefficientmaintenanceprogrammesbybeingabletoidentifyspecificassettypesandtheirlocation.

Condition Codes

Allassetdataarereturnedwithanupdatedconditioncode,andthesecodesareseparatedandanalysedforactionwhererequired.

Excellent condition

Nofurtheractionisrequiredontheseassetsbeforethenextscheduledassessment;

Good condition

Theseassetshavemorethantenyears’lifeexpectancyandwillbeassessedagainwithinthisterm;

Fair

Theseassetshavelessthantenyears’lifeexpectancy,butwilllastlongerthanfiveyearsandwillbeassessedagainwithinthisterm;

Poor

Thisassetcouldlastuptofiveyears;however,asitisinpoorcondition,futureassessmentwillberequiredduringthisterm;

Needs replacing

Anyassetswiththisconditioncodearegroupedintoareasalongwithanyotherurgentworkrequiredandaworkorderisraisedfortheasset(s)tobereplacedassoonaspossible;

Red tagged

Allredtaggedassetsareurgentlyinneedofreplacementandwork.UsingthenetworkanalysistoolbarintheGIS,theassetteamisabletoflagadisconnectorthatisplannedforfutureoutage,andtoidentifyanyoftheworkrequiredintheaffectedarea.

Workordersarethenraisedforthisworktobedoneduringtheplannedoutage.

2.8.4 NetworkDevelopment

A network development plan is required tomaintain, enhance and develop the operating capability of theWestpower network, and while there is no separate document published as a result of this process, it isnonethelessembodiedinthereplacement,enhancementanddevelopmentactivitiescontainedwithintheAMP.Thefollowingactivitiesarekeyelementsinthedevelopmentoftheplan:


1. Developandupdateaten-yearperiodloadforecastfollowingtherecordingofthesummerorwintermaximumdemandsand future development information. These load growthprojections are used as a basis for determining the likelytimingforthoseprojects.

2. Evaluate network limitations and select the bestdevelopment/configuration to alleviate each systemlimitation.

3. Complete the identificationof thenecessarymajorprojectonthebasisofrepeatedlyevaluatingthenetworklimitationsand selecting the best developments for each year of theforecastperiod,assumingcompletionoftheprojectsinthedesignandconstructionphaseandoftheprojectsidentifiedinearlieryearsoftheforecastperiod.

4. Collect any relevant data relating to the network’sperformanceorcapability.Theseincludesdataonswitchgearcondition,transformercondition,poorlyperformingfeeders,operationallimitations,etc.

5. Identify areas where future substation sites and/or futurecircuitsmayberequired.

6. Revisionmayberequiredintheperiodbetweentheannualreviewsifnewprojectsareidentifiedinthatareaorexistingprojectsaresignificantlychanged.

TherearetwodifferentplanningtypesconsideredbyWestpowerwhendevelopinganetworkdevelopmentplan:

• HVplanning,

• LVplanning.

HV planning incorporates a list of zone substations andassociated subtransmission feeders, a list of strategies fornetworkdevelopment,recommendationsfortheacquisitionoffuture substation sites, and HV circuit easements grouped byareatoensurethatsufficientcapacityisavailableinWestpowersubtransmissionandzonesubstationinfrastructure.

LVplanning isdevelopedtoensurethatadequatevoltage levelsaremaintained forall customersalongaLVdistributionatalltimesthroughoutthelifeoftheLVnetwork.Inordertoachievethis,accuratevoltagedropcalculationsarecarriedoutatthedesignstage.

Figure2.27showstheprocesstodeterminedevelopmentoptions.

2.8.5 AssetDataCollection

Historically,assetdatawerecollectedthroughas-builtdrawingsandrecordedonhardcopyfiles.TheinceptionoftheGISallowedthesedatatobeelectronicallyrecorded;however,muchofthesedatawereinitiallystillcapturedonpaperandmanuallytransferredtotheelectronicformat.AdvancesintechnologyhaveseenelectronicdatabeingcollectedinthefieldandautomaticallytransferredtotheGIS,creatingamoreaccurateandefficientdatacollectionsystemthanwasemployedinthepast.Thesedataarenowutilisedforanumberoftasksincludingassetconditionmonitoring,assetvaluation,workscoping,outageplanningandanumberofregulatorytasks.Confidenceintheintegrityofthedatahasgrownwiththecurrentdatacollectionmethodsusedandhighlevelsofaccuracyarenowbeingachieved.

Figure2.27-DataModelforReliabilityData

INTRODUCTION 55

Asmentioned,muchofthedatarelatingtoWestpower’sassetshavebeencollected.However,insomecases,dataaremissingorincomplete.ProgrammessuchasconditionassessmentandpillarboxinspectionshavebeeninitiatedtoensureallfielddataareincludedintheGISandMaximosystemsviathesynchronisationprocess.Thevariousassettypesandplansinplacetoensuredataaccuracyarelistedbelow.

2.8.5.1 PolesandSpans

Neworreplacementpolesandspansarerecordedduringthedesignphaseofeachjobandtransferredfromdesign software toGISwitha statusof “NotReady”. Once the line construction is completed, the status ischangedto“Active”andallrelevantattributionispopulated.

AnypoleorspanreplacementsnotrequiringdesignareupdatedontheGISbyelectronicmeansorthemanualpoledataform.

Pocketsofpoles and spanson thenetworkare yet tobe recorded;however, theseassets are rapidlybeingidentifiedandcorrected,primarilyviatheconditionassessmentprogramme.

2.8.5.2 UndergroundCables

Althoughmanyundergroundcableshavebeenelectronicallyrecorded,thereisstilla largenumbertoyetbeincluded.Programmes suchaspillarbox identificationand inspectionwill assist to identify those cablesnotcurrentlyincludedintheGIS.

Aprogrammetorecordmissingcablesandrelevantdatawasinitiatedin2010andwillcontinue,witheachareahavingcabledatasystematicallyrecorded.

Aswithspans,thespatialrecordingofundergroundcablesisintegraltoutilisingGISfunctionssuchasnetworktracing(connectivity),whichassetmanagementstaffarebecomingincreasinglydependentonforanumberoftasks.

2.8.5.3 PillarBoxes

Anidentificationandinspectionprogrammewasinitiatedin2008torecordallpillarboxesontheWestpowernetworkelectronically.Bothspatialandaspatialdataarerecorded,alongwithaseriesoftests.AnydefectsfoundarerecordedatthetimeofinspectionandareautomaticallyuploadedtotheGISwiththecoreinspectiondatatobeactioned.ThisprogrammewascompletedinFebruary2010.Anynewpillarboxadditionstothenetworkarespatiallyrecordedeithervialocalityplansorglobalpositioningsystem(GPS)readings.Similartopoledatacollection,attributiondatacanbegatheredelectronicallyorbycompletingthemanualpillarboxdataform.

2.8.5.4 TransformersandSwitchgear

There are a number ofmethods for collecting data for transformers and switchgear. As these componentsgenerally consist of a location (earths, fuses etc.) and an asset (transformers, disconnectors etc.), data arerecordedindependently.ThetransformerorswitchgearisrecordedonlyinMaximo,withthelocationdatabeingrecordedintheGISandbecomingavailabletoMaximouponnightlysynchronisation.Althoughtheyarestoredinadifferentdatabase,theassetdataareviewableontheGISwhenqueryingalocation.

AssethistoriesrecordedinMaximoincludeinformationsuchasassetmoves,servicinghistory(viaworkorders)andassetspecifications,whereasthelocationdataarerecordedinthefieldeitherbyhand-heldelectronicdevicesormanualdataentryforms.Averyhighlevelofconfidenceisawardedtothetransformerandswitchgeardata,withrecordsbeingperiodicallyaudited.


2.8.5.5 Summary

Processespreviouslyunavailablearenowinplacetoensureanynetworkadditions,deletionsorassetmovesarerecordedintheappropriaterepositories.Maximoworkflowsandauditingprocessesallowassetmanagementstafftoauditeachworkorder,andtocheckthatalldocumentationanddataentryiscompletedbeforeclosingoffthejob.Withthisinmind,theintegrityofthedatacanbeassuredandcanbeutilisedwithahighdegreeofconfidence.

2.8.6 MeasuringNetworkPerformance

ThefollowingsectionoutlinestheprocessbywhichWestpowerrecordsitsoutagedatatocomplywithdisclosurerequirements.

AllinterruptionstoWestpower’snetworkarerecorded,includingthoseontheTranspowergrid.Fordisclosurepurposes,allrelevantoutagedataarereportedonandgroupedbyclass(i.e.ClassA,B,CandD.ClassesBandCrelatetoWestpower;ClassesAandDrelatetoTranspower).

2.8.6.1 DataCollection

Atthetimeofanoutage,therearetwocategoriesofnotificationthatmayoccur:Alarm/OperatorandInformant/Customer.Thesenotificationstriggertherecordingpartoftheprocess.

Alarm/Operator:

Ifacircuitbreakeropens,analarmwilltriggerontheSCADAsystemandtheoperator(ifonduty)willnotifytheretailer.Iftheoperatorisnotondutythenthealarmwilltriggerapagerandtheon-calloperatorwillbecalledin.

Informant/Customer:

Ifacircuitbreakerhasnotopenedandthecauseoftheoutageis localisedtoadistributiontransformer(forexample),thiswillnotcauseanalarmontheSCADAsystem.Thefaultwillgenerallybeforwardedtotheretailerfromtheaffectedconsumer.

TheoutagewillthenbepassedonfromtheretailertoCallCare,whowillthennotifyElectroNetServices,whowillinitiateanyworkrequiredtofixthefault.AControlRoomoperatorwillcollectthefollowingdatawheneveranetworkinterruptionisexperienced:

Dateandtime(timepowerwentoffandtimelastcustomerwasrestored),

• Location,

• Descriptionofevent,

• Typeofoutage(plannedorunplanned),

• Feeder,

• Notification,

• Componentaffected,

• Cause,

• Voltageaffected,

• Protectionunitinformation,

• Network(WestpowerorTranspower).

Thisoutage information is currently stored in a geodatabase viaWestpower’sGIS. TheGIS is used to selecttransformers affected by an outage and, along with all related information, is recorded as a entry in thegeodatabase.

INTRODUCTION 57

CustomerinformationsuchasInstallationConnectionPoint(ICP)numbers,retailernumbersandsitenumbersareautomaticallyupdatedeverynightandstoredasaCommaSeparatedVariable(CSV)file.Thisfileisuploadedtothegeodatabaseandusedincalculationstofindthenumberofcustomersaffectedbyoutages.Thecustomersarelinkedtotheirrespectivetransformernumbers,sowhentransformersareselectedfromtheGIS,anaccuratenumberofcustomerscanbefound.

2.8.6.2 DataProcessing

SAIDI,SAIFIandCustomerAverageInterruptionDurationIndex(CAIDI)arethemostwidelyacceptedKPIsforelectricitynetworks.

WestpowercollectsthedatarequiredfromseveraldifferentinternalsystemsincludingtheGISandMaximotoperformthefollowingcalculations:

SAIDI (TotalSystemMinutesLostxNumberofCustomersAffected)/TotalNumberofCustomers

SAIFI NumberofCustomerInterruptions/TotalNumberofCustomers

CAIDI CanbederivedbydividingSAIDIbySAIFI

Insomepoweroutageevents,noteverycustomerhastheirpowerrestoredatthesametime.Becauseofthis,itisunrealistictousethestartandendtimeofanoutagetocalculateSAIDIandSAIFI.

1. Eachswitchingoperationisrecorded,includingthenumberofcustomersaffectedandthetimepowerwentoffandthetimepowerwasrestored.

2. ASAIDI/SAIFIfigureiscalculatedforthisoperation.

3. Tocalculatethetotalfortheoutage,theSAIDI/SAIFIforeachoperationissummed.

Figure2.28showsthedataprocess.

Figure2.28DataModelforReliabilityData


3.0 ASSETS COVEREDWestpowerownselectricity reticulationassets thatareused toprovidedistributionandconnectionservicestoelectricityretailersandgenerators.TheseassetsgenerallycompriseequipmentthatiscommontoallNewZealand ELBs and,wherever possible, industry standard assets have been employed. In particular, theAMPcoverstheelectricityandassociatedsystemsownedbyWestpower,comprising:

• Subtransmissionassets-Electriclinesandcables,includingassociatedeasementsandaccessways,operatingatvoltagesof33kVandhigher;

• Distributionassets-Electriclinesandcables,includingassociatedeasementsandaccessways,operatingatavoltageof11kV;

• Reticulationassets-400Velectriclinesandcables,includingassociatedeasementsandaccessways;

• Services - Connection assets at any voltage owned by Westpower for the purpose ofsupplyingasinglecustomer(notincludingthelineonthecustomer’spremises);

• Zonesubstations -HVsubstationsconnectedto thesubtransmissionnetwork.This includesallplantandequipment within the substations such as transformers, switchgear, structures and buswork, SCADA,protectionandmeteringequipment,andstationlandandbuildings;

• Distribution substations - Substations connected to the distribution network. This includes plant andequipment within the substations such as fuses, platforms, lightning arrestors and maximum demandindicators,togetherwithlandandfibreglasscovers,butexcludingtransformers;

• MediumVoltageswitchgear-Circuitbreakers,reclosers,sectionalisers,regulatorsanddisconnectorsusedinthedistributionandsubtransmissionsystems;

• SCADA,communicationsandprotectionequipment-SCADA,communicationsandprotectionequipmentandassociatedfacilitiesnotinstalledatzonesubstations.Thisincludescontrolroomequipment,radiorepeatersandfibre-opticsystemsinstalled,ownedandmaintainedbyWestpower;

• Distribution transformers - Standard transformersused indistribution substations ranging from5kVA to1000kVAandgenerallyhavingaprimaryvoltageof11kV;

• Ripplecontrol-Rippleinjectionequipment;

• Embeddedgeneration-GenerationunitsconnectedtoWestpower’snetworkbutnotnecessarilyownedbyWestpower;

• Capacitorunits-Forvoltagesupport;

• Mobilesubstation-Allowsimprovedmaintenanceaccesstoexistingsubstationsandforemergencyuseincaseofsubstationfailure;

• Buildings-SubstationbuildingswithintheWestpowernetwork.

WestpowerownassetsthroughoutthelengthoftheWestCoastoftheSouthIsland,anditsareaextendsaboutasfarasthedistancefromChristchurchtoDunedin(refertoFigure3.1).

AnoverviewofWestpower’snetworkdiagramcanbeseeninFigure3.3.

3.1 Asset Condition

Thepresent conditionof theaboveasset types is alsodescribed in this section,basedon information fromroutineinspections.

ThereaderunfamiliarwiththegeographicallayoutofthesystemisreferredtothemapsthroughoutSection3.

Thisassessmentof thepresentconditionof theassets,andthe implicationsof thison futurenetworkassetperformanceaftertakingassetcriticalityintoaccount,isthebasisfortheproposedmaintenanceprogrammesandnetworkdevelopmentdescribedinSection5.Theprimaryassetmanagementdriversare:

ASSETSCOVERED 59

Figure3.1-Westpower’sOperationalAreainRelationtoOtherSouthIslandElectricityLinesBusinesses

• Safety,

• Networkperformance,

• Economicefficiency,

• Environmentalresponsibility,

• Corporateprofile,

• Regulatorycompliance.

ThemajorityofthesenetworkassetsareshowninvaluetermsasapercentageofOptimisedDepreciatedReplacementCost(ODRC)inthepiechartofFigure3.2.

Figure3.2-ODRC-OptimisedDepreciatedReplacementCostasaPercentageofTotalNetworkAssetODRC.

20.1%

2.7%

12.3%

0.5%50.7%

10.8%1.9% 0.7% 0.3%

Zone Substations MV Switchgear Distribution Transformers

Spares Overhead Lines Underground Cables

Services Scada Comms Land Values


Figure3.3-DiagramofWestpower’sNetwork

33kV11kV

PIKE

11kV

LOGBURN

AtarauSwitchingStation(ATU110)

11kV

33kV

11kV

BLACKWATER

66kV

DOBSON(ATU110)

NGAHERE

33kV

REEFTON(RFN110)

11kV

GLOBE

11kV

11kV

ARNOLD

G 3MW

3.3kV

66kV

11kV

GREYMOUTH(GYM066)

6.6kV

66kV

11kVOTIRA (OTI011)

11kV

33kV

66kV

HOKITIKA(HKK066)

ROSS

11kV

11kV

WAITAHA

HARIHARI

11kV

WHATAROA

WAHAPO

11kV

11kV

G3MW

FRANZJOSEF

11kV

11kV

FOXGLACIER

110kV

66kV

33kV

11kV

6.6kV

3.3kV

LEGEND

GXPs

TranspowerOwned

(HKK066)

TwoMileRoad

Kawhaka

Coleridge66kV

ArthursPass66kV

Ina

nga

hu

a1

10

kV

TRANSPOWER

TR

AN

SP

OW

ER

66kV

KUMARA(KUM066) 10MW

11kV

G

SwitchingStation

RAPAHOE

11kV

ASSETSCOVERED 61

3.2 Transpower GXPs

Atarauswitchingstation,situatedonTranspower’sDobsontoReeftontoInangahuacircuit,wascommissionedbyTranspowerin2007tofeedthenewPikeRiverCoalMine.Westpowertakessupplyat110kVfromthisGXP.

TheElectricityCommission’sapprovalof theWCGUP in2008paved theway foranadditional110kVcircuitconstructedfromDobsontoReefton,andthiscircuitprovidestwogeographicallydiverseandrelativelystrongfeedsfromInangahuatoDobson,securingsupplyintotheWestCoastfromthenorth.Westpowerwasalreadywelladvancedwithsecuringpropertyrightsforthisroute,whichextendssome72kmthroughfarmlandandDepartmentofConservation(DOC)reserves,andhadbuiltupagoodrapportwithlocallandowners.

Thenewline,termedDOB-TEEA,wascommissionedinlate2011andprovidesn-1securitytotheAtarauGXP.AnagreementwasreachedbetweenTranspowerandWestpowerforWestpowertoconstructthenewlineandthensellittoTranspoweroncommissioning.

Priortothecompletionofthisline,therewasinsufficientcapacityintheTranspowernetworktosupplythisloadfromthesouthintheeventofafaultonthe110kVcircuitfromthenorth.Theloadwasthereforeinterruptible.

Thisproject,alongwitharelated14MvarswitchedcapacitorbankinstalledatHokitika,hasrestoredsecuritylevelstoagoodelectricityindustrypracticestandardforloadsofthesizeandtypesuppliedbyWestpower.

WestpowertakessupplyfromsevenTranspowerGXPsat110kV,66kV,33kVand11kVasshowninTable3.4.

MaintenanceofthemeteringequipmentattheseGXPsisTranspower’sresponsibility.

ThesouthernpartoftheWestpowernetworkisfedfromadouble-circuit66kVlinefromColeridge,whichissupportedbyalimitedcapacity66kVconnectionbetweenDobsonandKumara(seeFigure3.3).Thisprovidesanacceptablelevelofsupplysecurity,althoughsomeloadcurtailmentmaybenecessaryshouldacommonmodefaultaffectbothcircuitsofthe incomingdouble-circuit lineatthesametime.Theprobabilityofsucha faultoccurringisrelativelylow.

The constructionof the twin-circuit Kumara-Kawhaka line inMay1997byWestpowerhas greatly improvedsecurityofsupplytotheKumaraandGreymouthsupplypoints.ItisconsideredthatthelevelsofsecurityareappropriateforWestpower’snetworkinlinewithindustrybestpracticeforloadsofthissizeandtype.

3.3 Sub transmission Assets

Westpowerownsthreedistinctclassesofsubtransmissionassets,runningat110kV,66kVand33kV.The66kVassetsareleasedbacktoTranspowerforoperationaspartoftheirWestCoasttransmissionnetworkandtheseassetsareunderTranspower’soperationalcontrol.

*TheAtarauswitchingstationsuppliesLogburnRoadsubstationandthereforethetransformercapacityisapplicableforLogburnRoad

Table 3.4 - GXP Capacity and Load Profile

GXP Asset Owner Voltage (kV) Transformer Capacity (MVA)

Present Maximum Demand (MW)

Greymouth Westpower 66 2x15 13.444

Hokitika Westpower 66 2x20 18.452

Kumara Westpower 66 1x10 9.540

Dobson Transpower 110 2x17 13.793

Otira Transpower 11 1x2.5 0.694

Reefton Westpower 110 2x30 9.916

Atarau(SwitchingSta-tion)/LogburnRd* Transpower 110 1x30 1.104


KEY Substation


Subtrans Line 110kV

BWR-IGH-A

DOB-BWR-A

AHA-DOB-A



AHA-OTI-A

ATARAUATARAU


REEFTONREEFTON




OTIRAOTIRA


KUMARAKUMARA

Figure3.5-MapofTranspowerLinestoWestpower’sNetwork

ASSETSCOVERED 63

The110kVassetsownedbyWestpowerincludetheReeftonsubstation,wheretheinterfacepointsbetweenWestpower’s and Transpower’s assets are the incomingdisconnectorson the line sideof the110 kV circuitbreaker.

Westpoweralsoownsan8kmstretchof110kVlinefromTranspower’sAtarauswitchingstationtoanassociated20/30MVA110/33/11kVsubstationatLogburn.ThiswascommissionedbyWestpowerin2007aspartofthereticulationtothePikeRiverCoalMine.

3.3.1 AssetJustification

Subtransmissionassets,eitherat110kV,66kVor33kV,arerequiredtotransmithighlevelsofelectricalenergyover significant distances, prior to stepping the voltage back down to 11 kV for local distribution. The longdistancesinvolvedinreticulationofelectricityontheWestCoastmeanthattheseassetsareessentialforthecapacityandloaddiversityinvolved.

3.3.2 SubtransmissionAssetCondition

The condition of the sub transmission assets largely reflects their age and the quality ofmaterials used inconstruction.Ingeneral,the33kVlinesareconstructedwithconcretepolesandthe66kVlineswithhardwoodpoles.

Figure3.6showstheageprofileofsubtransmissionlines,bycircuitkilometre.

Thepresentconditionofanysubtransmissionlineislargelyafactorofitsage,thequalityofmaterialsusedandtheenvironmentalcorrosivenessofthelocationittraverses.

Westpower’ssubtransmissionlinesfallintofourbroadgroups:110kVpolelines,66kVwoodpolelines,33kVpolelinesand33kVfullyinsulatedlinesas33kVHendrixSpacerCable.

0

10

20

30

40

50

60

70

0-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 40+

Leng

th o

f Lin

e (

Km

)

Age (years)

33kv 66kv

110 kV

Figure3.6-SubtransmissionLineAgeProfile


*AllDRCandODRCvaluesaretakendirectlyfromthe2004ODVrevaluationexcercise.Whilethesevaluesarenowsomewhatoutofdate,theyprovideaconstantbasisforcomparisonwiththevaluationsofotherELBsbyusingthelastindustry-widevaluationdate.

3.3.3 110kVLines

Westpowerownsone110kVlinefromAtarautoLogburnRoad.Thislineis8kmofconcretepolesstrungwithNeonAllAluminiumAlloyConductor(AAAC).

Table3.7summarisesthequantityofthe110kVlinebycircuitlength.

3.3.4 66kVLines

DRC* - $2,074,730

ODRC - $2,074,730

Westpowerownsthreeoverhead66kVsubtransmissionlines.TwooftheseareconnectedtotheWestpowerKumaraSubstation,whileanotherisanextensionoftheTranspower-ownedTMR-OTIcircuit.

Asdiscussedabove,allthreeoftheseassetsarecurrentlyleasedtoTranspoweronalong-termleasearrangement.

ThelinebetweenGreymouthandKumaraisa25kmhardwoodpolelinestrungwithDogAluminiumConductorSteelReinforced(ACSR)conductor.Thiswasconstructedin1977toconnecttheKumarapowerstationtotheWestpowerGreymouthsubstationandthentotheTranspowergrid.

The66kVdouble-circuittreatedhardwoodpolelinebetweenKumaraandKawhakawascommissionedin1997,andthiswassubsequentlyleasedtoTranspower,allowingthemtoreconfigurethegridontheWestCoast.Thelineis11kmlongandusesIodineAAACconductoronbothcircuits.

Themostrecentlyconstructed66kVline,betweentheTwoMileandHokitikasubstations,wascompletedinJuly2002.This,too,isadouble-circuitline;however,pre-stressedconcretepoleshavebeenusedtosupportthe7.8kmofIodineAAACconductor.

Westpowerhasnoundergroundcablesattransmissionvoltagesof66kVandabove.

Table3.8summarisesthequantityof66kVoverheadlinebycircuitkilometre.

3.3.4.1 66kVWoodPoleLines

TheGreymouth-Kumara66kVlineconstructedin1977wasconstructedwithde-sapped,untreatedhardwoodpoles,whicharenowshowingsignsofearlyground-linedeterioration.Arecentmajorground-lineinspectionhasshownthatthereisnoreasonforimmediateconcern,butamanagementplanneedstobeputintoplacewithinthenextfiveyearstocontainanyriskofprematurefailure.

Table 3.7 - 110 kV Lines Summary

Type Circuit Length (km)

LightOverhead 0

MediumOverhead 0

HeavyOverhead 9



LightOverhead 0

MediumOverhead 60

HeavyOverhead 0

ASSETSCOVERED 65

Figure3.9--Westpower’s33kVNorthandSouthNetworks

Westport


GLOBEGLOBE

DOBSONDOBSON

REEFTONREEFTON

FOX GLACIERFOX GLACIER

FRANZ JOSEF.FRANZ JOSEF.

ROSS ROSS

RAPAHOERAPAHOE

ARNOLDARNOLD

HARIHARIHARIHARI

WAITAHAWAITAHA

GREYMOUTHGREYMOUTH

HOKITIKAHOKITIKA

WAHAPOWAHAPO

KUMARAKUMARA

PIKEPIKE

WHATAROAWHATAROA

NGAHERENGAHERE

KEY

33kV Subtransmission Line

66kV Transmission Line (Westpower)

66kV Transmission Line (Transpower)

110kV Transmission Line

Westpower Substations


TheKumara-Kawhakalinewascompletedin1997andusedtreatedhardwoodpoles,whichareexpectedtolastforatleast45years.Thislineisinexcellentcondition,withannualpatrolsshowingnosignsofdeterioration,aswouldbeexpectedfromabrandnewline.

Bothlinesusestand-offporcelaininsulatorsandthishasgreatlyreducedthecomponentcountoneachpole.

Ofnote,boththeGreymouthKumaraandKumaraKawhakacircuitsareleasedtoTranspower,whooperatesthemaspartofthenationalgrid.Aperformance-basedcontractexistsbetweenTranspowerandWestpower,wherebyWestpowerprovidesaminimumlevelofreliability,andthis,inturn,requiresahigherthanusualstandardofmaintenance.

Duringtheearly1990s,aprogrammeofpolebandagingwascarriedoutonapproximately50%of thepolesonthisline.Thisinvolvedcleaningoffanyrottensapwood,placingaheatshrinkbandagearoundthepoleatthe ground-line and injecting a fungicidal emulsion to halt any further deterioration. In 1994, however, thisprogrammewasdiscontinuedbecauseofconcernsovertheeffectivenessoftheprocess.

3.3.5 33kVLines

DRC - $6,566,784

ODRC - $6,566,784

Thereare twogeneral areas servedbyWestpower’s 33 kV subtransmissionnetwork,onebasedaround theDobsonandGreyValleyareas,andtheotherservingSouthWestland.ThesetwoareasareconnectedbetweenGreymouthandHokitikaviaKumarathroughthe66kVnetwork.

Figure3.9showsthegeographicalspreadofthesetwoassetareas.

Transpower’sDobsonpointofsupplyservesasthehubofthenorthernsubtransmissionsystemandisusedtofeedsubstationsatRapahoe,Ngahere,ReeftonandArnold.ThelinetoArnoldwasoriginallybuiltinthe1930sanduses7/.080”copperconductor.

ExceptforashortlengthofMinkACSRlineoverMtHerculesandsomefullyinsulated33kVoverheadlineinSouthWestland,therestofthesubtransmissionlinesarestrungwitheitherDogACSRorIodineAAACconductor.

The33kVsubtransmissionlinefromHokitikatoHarihari,originallyconstructedin1966,waspurchasedfromTranspower.Thelargemajorityoftheremaining33kVassetshavebeenconstructedsince1983andaremainlyofconcretepoleconstruction.

Table3.10summarisesthequantityof33kVoverheadlinebycircuitlength.

3.3.5.1 33kVPoleLines

These linesaremostlydouble-circuitunder-builtconstruction(33kVabovewith11kVand/or400Vcircuitsbelow)wiredinACSRandAAACconductor,andarebetween4and38yearsold.

Threedistinctconstructiontypesarepresentinthesubtransmissionnetwork:

• HardwoodpolesontheHarihari-WhataroaandDobson-Arnoldlines.

• Stresscrete12.2mpre-stressedconcretepoles(usedonthemajorityoflinesconstructedinthelast15years);

• Twotypesoffullyinsulatedconstructiononhardwoodpoles.



LightOverhead 267

MediumOverhead 0

HeavyOverhead 0

ASSETSCOVERED 67

3.3.5.2 33kVOverheadLineReliability

MostofWestpower’sreticulationconsistsofoverheadlines.

Overthepast15years,allofthemajor33kVand11kVfeedershavebeenreplacedorrefurbished,andareinverygoodconditionoverall.

Whileoverheadlinesaresubjecttomorefaultsthanundergroundcables,duetosuchthingsaslightningandbirdstrikes,itisrelativelyeasyandquicktogetthembackintoservice.

Themaximumrepairtime(aboutfourhours)isrequiredwhenacomplexpolestructureisdamageddueto,say,avehiclerunningintoit.

DistributionautomationequipmentinstalledoverrecentyearshasallowedWestpowertodiagnoseandlocateruralfaultsquickly,andthenrestoresupplyremotelytoadjacentareaswithouthavingtogetstaffonsite.

Sparesofalltypesofconductorsandpolesarekeptinstocktocovermosteventualities.Accesstoothernetworkcompanies’stocksislikelyintheeventofamajordisaster.

3.3.6 33kVCables

InWestpower’scase,thehighestvoltageundergroundcablesitoperatesareatavoltageof33kV.TheseareofstandardPaper-InsulatedLead-CoveredSteelWireArmoured(PILCSWA)constructionoveraveryshortdistanceoflessthan100mwithbackup.TheseareusedasfeedercablesattheDobsonsubstation.

In general, underground cables are very reliable as they are not exposed to the external environment and,if carefully laid, should give at least 50 yearsof good service. Themost likelymodeof failure is damagebycontractorsusinghydraulicexcavators.

Thefailurerateofcablesisrelativelylow;however,repairtimesarecritical.Undergroundcablesarethemajorconstraintinthisarea.

3.3.6.1 Hendrix33kVSpacerCable

InSouthWestland,therearetwosectionsoffullyinsulated33kVoverheadconductors,bothconstructedusingtheHendrixSpacerCableSystem.

Byusing this specialist conductor,Westpowerwas able tomitigate theenvironmental effectson a sensitiveenvironmentwithhighscenicvalues.Infact,thislinerunsthroughaNationalPark.A2kmstretchofthiscablealsorunsclosetoLakeWahapo(thisusesthreeseparate, fully insulatedconductors,heldapartby insulatedspacers).

TheHendrixsystemhasa40-yeartrackrecordintheUnitedStatesandhasproventobeveryreliable.

Spacer cablewas installed for a 6 km stretchof line around LakeMapourika in 2000, and this replaced theexistingAerialBundledCable(ABC)systemthathadproventobeunreliable.

Thisnewsystemalsoinvolvesfullyinsulatedoverheadconductors,butinsteadoftheindividualphasesbeingbundledtogether,theyarespacedapartbyinsulating“spacers”everytenmetres,andsupportedbyaseparate,highstrengthcatenarywire(Figure3.11).

Experiencetodatewiththissystemhasbeenexcellent,evenwhenlargetreeshavefallenacrossthecatenarywire,as thesystemcontinues tooperatewithout theconductorsbeingdamaged.Repairs canalsobemadequicklybecausethereisnoneedtoapplystresscontrolmeasureswhenjointing.


3.3.7 ConditionofSpecificLineComponents

3.3.7.1 WoodPoles

The Greymouth-Kumara 66 kV line wasconstructedin1977usinguntreatedhardwoodpoles and these are now beginning to showsignsofdeterioration.However,approximately50%of the linehad ground-linepreservationwork done on it in the early 1990s, whichshould extend the life of the poles involved.Overthenextfewyears,conditionassessmentofthelinewillbesteppedupanditislikelythatapolereplacementprogrammewillbeinitiatedtowardtheendoftheplanningperiod.

The 33 kV line south of Hokitika to Harihariwasconstructedinthemid-1960sandalargeproportion of the untreated hardwood poleshavenowreachedreplacementcriteria.Apolereplacementprogrammewasinitiatedin2008andthisisexpectedtocontinuethroughuntil2012.

3.3.7.2 ConductorsandConductorAccessories

Copper7/.080”conductorisfittedtotheDobson-Arnoldlines.Muchofitisstillinreasonableconditionandcanremaininserviceforafurthertenyears.However,vibrationdamageandcorrosionhastakenitstoll.

Noreplacementisplannedatthisstage,asanyfurtherhydrogenerationdevelopmentatArnoldwillrequiretheconductortobeupgradedanywaytoremoveaneffectiveconstraint.

Mostoftheconductorinstalledsincethe1960suptothemid-1990s,hasbeenconventionalDogACSRwithagreasedsteelcore.AllconventionalACSRispronetocorrosion,especiallywherethelineissubjecttowindbornesaltcontamination.Thiswillbecarefullywatched,althoughthereisnoevidencetodateofsuchdeterioration.

Since the mid-1990s, Iodine AAAC conductor has been used exclusively for subtransmission lines and theenhancedcorrosionprotectionaffordedbythisalloymaterialshouldresultinatleast60years’effectivelife.

Mostlinesarefittedwithspiralvibrationdampers,whereappropriate,andthishasgreatlyreducedtheincidenceofvibrationdamagetoconductorsandfittings.TheArnold-DobsonandGreymouth-Kumaralinesareexceptionstothis,andastudywillbecarriedouttodeterminewhetheraretrofittingprogrammeiswarrantedtominimiseanyriskofdamage.

3.3.7.3 InsulatorsandInsulatorFittings

Thereareanumberofolderporcelaindiscsnowknown tobeunreliabledue to inherentdesign faultsplusin-serviceinternaldeterioration.Thishasnotbeenamajorproblemonsubtransmissionlinesbecauseoftheuseofmultiplediscs,whichaffordssomeredundancy.Nevertheless,theeffectsofongoingdeteriorationwillhavetobetakenintoaccountinthelifecyclemanagementplan.

Replacementinsulatorsareeitherglassorpolymerdiscinsulatorswithroundpins.

Problemshavebeennotedwith the 33 kV EthylenePropyleneDieneMethylene (EPDM)polymer dead-endinsulatorsthathavefailedandshowedsignsofchalkingandcracking.Thecrackingisthroughthesheds,andaxialtothefibreglassstrengthmember,withnoapparentpenetrationtowardthecore.

Figure3.11-Hendrix33kVSpacerCable

ASSETSCOVERED 69

Aninvestigationwascarriedouttoassesstheseriousnessoftheproblemandtherisk,ifany,thatthisapparentdeteriorationposes.An independent consultant suggested that the LAPP-manufactured33kVunitshaveaneffectivein-servicelifeofapproximatelytenyears,whichsoonwillbeexceeded.Areplacementprogrammewillneedtobeinitiatedtomitigatetheriskoffuturefailure.

3.3.8 ConditionofAccessRoads

TheDobson-Arnoldlineisservicedbyagoodqualityaccessroadthatmaybeusedbytrucksandfour-wheeldrivevehicles.WhileitisnotWestpowerpolicytoprovideforthisstandardofaccessroad,itsexistenceowesmuchtotheline’sheritageasaTranspowerasset.Theroadisinexcellentconditionforthepurposeintended.

TheKumara-Kawhakalinehadanaccessroadconstructedtoallowthelinetobebuilt,andissuitableforfour-wheeldrivevehicleandexcavatoraccess.Thisroadisinreasonableconditionforthelevelofuserequired.

NospecificaccessroadshavebeenconstructedtogainaccesstotheGreymouth-KumaraorMtHerculeslines.

Acontingencysumisincludedintheannualbudgettoprovidemaintenanceonalreadyformedaccessroads.

3.4 Distribution Assets

DRC - $25,183,835

ODRC - $24,988,272

Electriclinesandcablesoperatingatavoltageof11kV,includingassociatedeasementsandaccessways,makeupthebulkofWestpower’sinfrastructureassets,intermsofbothvalueandnumber.

Figures3.12and3.13showtheextentofWestpowerdistributionlineassetsspreadthroughoutthelengthoftheWestCoast.


ThesearecoreassetsforELBs,andcomprisethedistributionlinesandcablesthatdeliverelectricityat11kVtothedistributionsubstationsthatsupply415Vor230Vtoindividualinstallations.Theseassetsarethereforeessentialtotheoperationofthenetwork.

3.4.2 11kVOverheadLines

Table3.14belowliststhetotaloverheaddistributionlineassetsownedbyWestpower.

Westpowerownsalargevarietyofdistributionlinesandcablesthatcoverawideageprofile.Overheadlinescoverthreebroadgroupsincluding:

• Earlyhardwoodpolelines,

• Concretepolelines,

• Treatedsoftwoodpolelines.

Since1972,mostofthemajorlineshavebeenreconstructedwithconcretepoles,andAAACorACSRconductors,andthishasresultedinafewremainingpocketsofearlierhardwoodlinesintheGreymouthandReeftonareas.Notwithstandingthis,therearesomenotableexceptions,suchastheFox-ParingaandCoastRoadlines,whichusedtreatedsoftwoodpolesforenvironmentalandconstructabilityreasons.



LightOverhead 1007

MediumOverhead 391

HeavyOverhead 7


MOANAMOANA

INANGAHUAINANGAHUA

HAUPIRIHAUPIRI

PUNAKAIKIPUNAKAIKI

DOBSONDOBSON

REEFTONREEFTON

RAPAHOERAPAHOE

KOKIRIKOKIRI

GREYMOUTHGREYMOUTH

NGAHERE NGAHERE

KUMARA KUMARA

PIKE RIVERPIKE RIVER

KEY

Westpower Distribution Network 11 kV

Figure3.12-NorthernSectionofWestpower’sDistributionLineAssets

ASSETSCOVERED 71

OTIRAOTIRA

KANIEREKANIERE

PARINGAPARINGA



ROSSROSS

HARIHARIHARIHARI

WAITAHAWAITAHA

HOKITIKAHOKITIKA

WAHAPOWAHAPO

KUMARA KUMARA

WHATAROAWHATAROA

KEY

Westpower Distribution Network 11 kV

Figure3.13-SouthernSectionofWestpower’sDistributionLineAssets


Softwood or concrete poles are used for allreplacement or new construction work, and thesetypesmakeupover60%ofthepolepopulation.AnexampleofamodernconstructionisshowninFigure3.15.

The insulators consist of porcelain pin insulators,andamixtureofporcelain,glassandpolymerstraininsulators. Westpower has used stand-off postinsulators in some environmentally sensitive areas.Apart from these sections, however, conventionaloverheadconstructioniswidelyemployed.

3.4.2.1 DistributionLineCondition

Theconstructionof lines inthepasthasoftenbeendrivenbycustomerdemandsandpoliticalinfluences,whichhasresultedintheseeminglyerraticnatureofthe line ages. Amajor undergrounding programmeextending throughout the 1980s, coupled with anoverhead feeder replacement extending from 1992throughto1999,hasresultedinanaveragelineageof20years.

Thepresentconditionofanydistributionlineislargelyafactorofitsage,thequalityofmaterialsusedandtheenvironmentalcorrosivenessofthelocationsittraverses.

Itisdifficulttogeneraliseabouttheconditionofdistributionlines.However,ifweexcludethoselinesinsevereenvironmentsandlookattherest,thenWestpower’slinestendtofallintothreebroadgroups.

Figure3.16showstheageprofileofdistributionlines,bycircuitkilometre.

0

50

100

150

200

250

300

0-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 40+ UNKNOWN

Leng

th of

Line

(km)

Age (years)

Figure3.16-DistributionLineAgeProfile

Figure3.15-ModernLineConstruction

ASSETSCOVERED 73

3.4.2.2 EarlyWoodPoles

Theselinesare11kVsingle-circuitanddouble-circuitconstruction,andmanyofthemarearound40yearsold.Fewofthe lineshavehadreplacementsofmajorcomponentstokeeptheminserviceand,overall, theyaregenerallyinpoorcondition.Generally,theconductors(usuallycopper)havesomelimitedremaininglife.

Becauseofthemajorreplacementprogrammerecentlycompleted,woodpolelinesaregenerallylimitedtospurlinesortheremoteendsofruralfeeders.

3.4.2.3 ConcretePoleLines

Theselinesaremostlysingle-circuit,wiredinACSRandAAACconductor,andarebetween1and25yearsold.

Twotypesofconcretepoleswereused:

• Theearlierheavy-reinforcedtypemanufacturedbyWestpowerfromthe1970suntiltheearly1980s.Theseareoftenreferredtoas“Hokitika”concretepolesbecauseofwheretheyweremanufactured;

• Pre-stressedconcretepolesmanufacturedsincetheearly1980sbyalocalbridge-beambuilderunderlicensetoStresscrete.

Thepolesarestructurallysoundandhaveanexpectedlifeof60years.

Therehasbeensomeconcernregardingthelong-termeffectoftheleachingoutofcementbelowgroundlevelinthe“Hokitika”concretepolesincertainsoilconditions;however,theextenttowhichthisaffectsthestructuralintegrityofthepoleisstillunderinvestigation.

3.4.2.4 TreatedSoftwoodPoleLines

Constructionoftreatedsoftwoodpolelinesbeganin1992foreconomicreasonsandcontinuedthroughuntil1994 formain lines,when the cost differential between concrete and treated softwood poles underwent areversal.TheselinesarewiredinACSRorAAACconductor.

3.4.3 11kVDistributionLineComponents

Table3.17summarisesthepresentnumbersofspecificdistributionlinecomponents.

Table 3.17 - Summary of Distribution Line Components

Components No. %

Structures (11 kV)

Poles-Wood Hardwood 2083 16%

SilverPine 13 0%

Softwood 1162 9%

Larch 4 0%

Poles-Concrete Hokitika 2992 23%

Stresscrete 6485 50%

Spuncrete 15 0%

Buller 42 0%

Other 205 2%

TotalStructures 13,001 100%

Crossarms

11kV 22296 70%

400V 7913 25%

Service 1503 5%

TotalCrossarms 31,712 100%


3.4.3.1 WoodPoles

Thereareapproximately2200distributionwoodpoles inservice.Anestimated252polesareassessedtobecurrentlyatreplacementcriteria,orwillreachthemwithinfiveyears.Approximatelyanother344areestimatedasneedingtobereplacedbetween2012and2015.


Copperconductorisfittedtothemajorityofolderlines.Muchofitisstillinreasonableconditionandcanremaininserviceforafurther10-20years.However,vibrationdamageandcorrosionhavetakentheirtoll.

Most of the conductor installed since the 1960s has been conventional ACSR with greased steel cores. AllconventionalACSRispronetocorrosion,especiallywherethelineissubjecttowindbornesaltcontamination.MuchoftheearlyACSRinexposedareashasbeenidentifiedforcarefulinspectionoverthenexttenyearstodeterminewhat,ifany,replacementprogrammeshouldbeundertaken.


Thereareanumberofolderporcelaindiscsnowknown tobeunreliabledue to inherentdesign faultsplusin-serviceinternaldeterioration.Inparticular,therelativelyrecentinternationaldiscoverythatolderconventionalporcelaincandevelopporosityduringitsservicelife(leadingtopuncturesandmechanicalseparation)plustheknownpoorqualityofmuchoftheolderporcelaininsulationhaveprovidedaddedweighttothereplacementprogramme.

Replacementinsulatorsareeitherglassorapolymerdiscinsulatorwithroundpins.

ProblemshavealsobeennoticedwithEPDMpolymerinsulatorsshowingsignsofchalkingandevencracking.Aninvestigationiscurrentlyunderwaytoassesstheseriousnessoftheproblemat11kVandtherisk,ifany,thatthisapparentdeteriorationposes.

Aconditionassessmentprogrammewasbeguntoconfirmtheservicelifeofanumberofolder33kVporcelainpininsulatorsusedonthe33kVsubtransmissionlinefromNgaheretoReefton.

Approximately800oftheseinsulatorswereinstalledsecond-handinthemid-1990sasacost-savingmeasure.Initially,theywereinstalledinthe1960sonthelinetoRuatapusouthofHokitika,butthenremovedabouttenyearslaterandplacedinstorageuntilbeingusedonthelinetoReefton.

Duringcommissioningofthelinein1999,twooftheseinsulatorsfailed,resultinginspectacularearthfaults.A further insulator failed in January2000 followinga severe lightning storm.Thesecombinedevents, raisedsomedoubtastotheongoingserviceabilityofthisparticulartypeofinsulator.Subsequentanalysisofarandomsampleofinsulatorsconfirmedthatthegeneralpopulationofinsulatorsisingoodcondition,however,andnofurtherremedialactionisrequired.

CorrosionproblemshaverecentlybeenidentifiedwiththeDulmisonpre-formedinsulatortiesusedtoattachaluminiumconductorstoinsulators.Whentheseareinstalledincoastalenvironments,severecorrosionoccursundertheneoprenecoverusedtocushioncontactbetweentheHelitieandtheinsulator,leadingtocompletefailureoftheunit.

Table 3.17 - Summary of Distribution Line Components

Components No. %

ConductorsandAccessories

11kVConductor(km) 1424

400VConductor(km) 163

Insulators 11kV 98320 61%

400V 47327 30%

Service 14402 9%

TotalInsulators 160,049 100%

ASSETSCOVERED 75

3.4.4 11kVCables

ThemajorityofWestpower’sundergroundHVcablenetworkconsistsof11kVcableofbothPILCSWAandCross-linkedPolyethylene (XLPE) construction.Bothof thesearedry-type constructions that allow for joints tobereadilymadewithinfourhoursafterthefaulthasbeenlocatedandthetrenchdug.

IntheGreymoutharea,thereticulationintheCentralBusinessDistrict(CBD)consistsofadouble-redundantringof11kVcables.At leasttwoseparateHVcableswouldhavetofail tocauseanoutageofadistributiontransformer.Evenifthiswastohappen,theLVnetworksarehighlyinterconnectedandwouldcontinuetosupplymostoftheload.

AllofWestpower’scablesareoperatingwellwithintheirthermalratings,eventakingaccountofthepossibilityofpoorthermalresistivitybackfill.

CablemakesupaverysmallportionofWestpower’stotalHVassets,andisgenerallylimitedtoCBDsorzonesubstations.Thereare,however,someexceptionstothis,suchastherecreationalareasofMoanaandPunakaiki.

Throughoutthe1980s,Westpowerhadapolicyofundergroundingcablesinurbanareasandthisresultedinasignificantamountoftheoverheadreticulationinthoseareasbeingreplaced.Asacaseinpoint,themajorityofHokitikaisreticulatedunderground,andundergroundHVcablesareusedthroughouttheCBDandneartheairport.

Whilesomeoftheolder11kVcablesaroundGreymouthwereinstalledinthe1950’s,manyofthesehavesincebeenoverlaidorreplacedwithmodernequivalents.PILCSWAwasthestandardfornormaldistributionpurposesuntilthemid-1980s,whenXLPEinsulationgraduallycameintovogue.

Table3.18showsthedistributionof11kVundergroundcablesintheWestpowernetwork.

3.5 Reticulation Assets

DRC - $5,306,762

ODRC - $5,306,762

Theseassetsinclude400Voverheadlinesandcablesusedtoreticulateelectricitytotheboundaryofconsumer’spremises.


Oncetheelectricityis“steppeddown”from11,000Vto415Vatdistributionsubstations,the415Vreticulationassets,comprisingoverheadlinesandcables,arenecessarytodeliverelectricitytotheboundariesofindividualinstallations.Assuch,theseassetsareacorepartofWestpower’snetwork.

3.5.2 Overhead400VLines

Westpower uses a conventional overhead LV configuration with insulated conductors and cross arms; ABCconstructiontechniquesarenotemployed.

Intermsofconductorselection,copperwasusedextensivelyuntilthemid-1970s,butwasgraduallyreplacedwithaluminiumcoveredPolyvinylChloride(PVC)becauseofeconomicandconstructabilityconsiderations.

Table 3.18 - 11 kV Undergound Cable Summary


HeavyUnderground 0

MediumUnderground 42

LightUnderground 13


VirtuallyalloftheLVnetworksfromHokitikasouthwards,andsomewithintheurbanareaofGreymouth,havebeenreplacedinthelast20yearsbyundergroundcable.

However,insomeolderareassuchasReefton,therearestillsectionsofolderwoodpoleLVreticulation.

Westpowercurrentlyowns169circuitkmof400VLVlineassets,andthisisnotexpectedtochangedramaticallyovertheplanningperiod.ThelargestsinglecontributiontomoreLVlinesislikelytocomefromnewsubdivisions.Inthiscase,thereticulationwillalmostcertainlybeofundergroundconstructionbecauseoftherequirementsoflocalDistrictPlans.

ManyofthefactorsdescribedinSection3.4“DistributionAssets”–applyequallytotheirLVcounterparts.

Table3.19listsasummaryof400VoverheadlinesinWestpower’snetwork.

ThereasonforthisisthatmostoftheLVconstructionwascarriedoutatanearlytimeintheurbanareaswherethepopulationdensitywasthegreatest.Overtheyears,this largepopulationofassetsagedtogethertothepointwheretheyreachedtheendoftheirservicelife.This,inturn,requiredamajorrefurbishmentprogramme.

Ingeneral,theagedistributionoftheseassetsshowsanaverageageofaround20years.Figure3.20showstheagedistributionprofilefortheseassets.

3.5.2.1 SouthWestland

TheareasofHokitikaandSouthWestlandhavelargelybeenrebuiltoverthelast15years.Duringthistime,mostoftheurbanreconstructionhasbeencarriedoutusingundergroundreticulation,whichhasalifeofupto50years.LittlefurtherLVworkisthereforeplannedintheseareas.

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

0-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 40+

Le

ng

th o

f L

ine

(k

m)

Age (years)

Figure3.20-400VReticulationLineAgeProfile

Table 3.19 - 400 V Lines Summary


Light 125

Medium 49

Heavy 0

ASSETSCOVERED 77

3.5.2.2 Greymouth

InthecentralGreymoutharea,someoftheoldestlineswereplacedundergroundduringthe1980’s.Thechangeinfocusduringthelate1980’stoamorecommercialfootingledtothedemiseofundergroundingbecauseofthesubstantiallyhighercapitalcostinvolved.Fromtheearly1990son,theremainingrefurbishmentworkhasbeencarriedoutwithoverheadreticulation.

TheLVnetworksinthesatellitetownsofBlaketown,CobdenandRunangahavebeenreconstructedoverheadinthelasttenyearsandarecurrentlyingoodcondition.

3.5.2.3 Reefton

TheReeftonareaconsistsofsomeveryoldoverheadLVlineswhichareinneedofreplacement.Duringthe1980’stherewasanundergroundingprogrammeinplace,whichresultedinseveralstreets,includingthemainbusinessarea,beingundergrounded.InconjunctionwithTelecom,someareaswillcontinuetobeundergroundedwherecostsharingcanbeachieved.

Several small pocketsof LV lineswill alsoneedattentionduring theplanningperiod, and the required levelof replacement for these areaswill be identifiedduring condition assessment of the asset. Thiswill enablemaintenance to be effectively targeted and provide a solid foundation for the move to a Condition-BasedMaintenance(CBM)programme.

3.5.2.4 Underground400VCables

AvarietyofundergroundcabletypeshavebeenusedforLVreticulationspanningaperiodofsome30years.

Intheearlydays,single-corealuminiumcables,witheitherastrandedorsolidcore,werewidelyused.Overtime,however,multi-corecablesbecamepopularbecauseofthecostadvantages.

Astandardcablenowusedinresidentialareasis95mm2strandedaluminiumwithacopperneutralscreen.FordenserCBDareassuchasthetownofGreymouth,four-core185mm2cableswereused.

Currently,allnewurbansubdivisionsarereticulatedundergroundasarequirementoftheappropriateDistrictPlans.

Withtheexceptionofasmallnumberofold400VfeedercablesintheGreymouthCBD,mostoftheundergroundLVreticulationthroughoutWestpower’sareaislessthan20yearsoldandingoodcondition.

Theundergroundfittingsusedarealsoingoodcondition,mainlybecauseoftheirage;however,constantminormaintenanceisstillrequiredtoovercomeproblemsduetocorrosionorwateringress.

Table3.21showsthedistributionof400Vundergroundcable.

3.5.3 ConditionofSpecificLVLineComponents

3.5.3.1 WoodPoles

MostoftheLVwoodpolesareveryold,predominantlyhardwoods,andrangeinconditionfromverypoortogood.Theirconditionisbestassessedthroughanobjectivetestingprogramme.

Table 3.21 - 400 V Underground Cable Summary


Light 154

Medium 0

Heavy 0



All of theoverhead lines constructedover the last 20 years consistmainlyofPVC-coveredAAACandare ingenerallygoodcondition.

Forabout20yearspriortothis,PVC-coveredcopperconductorswereused,andthesealsoareingoodcondition.WhereaLVlineisreplacedorrefurbished,thistypeofconductorisreusedifitisingoodconditionandofanadequatecross-sectionalarea.

Alllinesover40yearsofagethathavenotbeenrefurbishedduringtheirlifestillusetheoriginalbraid-coveredconductors.Theconditionoftheseconductorsisverypoorandcouldbecomeasignificantsafetyhazardifnotattendedtointheshortterm.

Otheraccessoriesdemonstrateaconditioncommensuratewiththeageofthelineandarereplacedaspartoftheoverallreplacementprogramme.

3.6 Services

DRC - $637,381

ODRC - $637,381

Thisassetconsistsoftheequipmentusedtoconnectapproximately12,000consumerstoWestpower’snetwork.

Themajorcomponentsofthisassetaretheserviceprotectivedevices,whichmaybeoneofthefollowing:

• 400Vrewireablepolefuse,

• 400VHighRupturingCapacity(HRC)polefuse,

• 11kVdropoutfuse,

• 11kVcircuitbreaker.

Inthelastcase,theconsumerwouldownthe11kVcircuitbreakerandtheconnectionassetwouldbean11kVdisconnector.

Theservicelineonthepremisesoftheconsumerisownedandmaintainedbytheconsumer.


Servicesincludeassetsrequiredtomakethefinalconnectionbetweenacustomer’sinstallationandWestpower’snetwork.ThesearenecessaryforanindividualcustomertotakesupplyfromWestpower.

3.6.2 ServiceLineCondition

Servicelinesoncustomers’premisesareownedandmaintainedbytheindividualcustomers.

Notwithstandingthis,therearesomeservicelineswhicharenotofanacceptablestandardduetoinsufficientclearanceorotherreasons.Westpowerisresponsibleforbringingtheseuptostandardbeforetransferringthemtothecustomer.

MostservicelinesareeitherPVC-coveredcopperorneutralscreenedcopper,andshouldgivegoodserviceformanyyears.Afewoftheveryoldservicesarestillofthebraidvariety,andthesearereplacedasamatterofcourseandatWestpower’scostwhenasectionofLVlineisrefurbishedorreplaced.

ASSETSCOVERED 79

3.7 Zone Substations

DRC - $11,810,454

ODRC - $11,786,895

Zonesubstationsareusedtotransformpowerfromtransmissionandsubtransmissionvoltagesof33kVandhigherdowntoWestpower’sstandarddistributionvoltageof11kV.

Thesesubstationscomprisebuildings,switchyardstructuresandassociatedhardware,HVcircuitbreakers,powertransformers,instrumenttransformersandamultitudeofotherassociatedpowersupplycablingandsupportequipment.Furthermore,thesubstationsrangeinsizefrom1MVAto40MVAandareusedtofeedlargeareasofWestpower’snetwork,thusplayingacriticalroleintheoverallreliabilityofWestpower’snetwork(pleaserefertoappendixC“NetworkReliabilitybyZoneSubstationandFeeder”forfurtherinformation).

Table3.22showsthezonesubstationcapacity,assetownerandcurrentmaximumdemandseenin2011.

Table 3.22 - Zone Substation Capacity and Maximum Demand

Substation Asset Owner Voltage (kV) Present Maximum Demand (MW)

Transformer Capacity (MVA)

Greymouth Westpower 66 13.444 2x15

Hokitika Westpower 66 18.452 2x20

Kumara Westpower 66 2.361 1x10

Dobson Westpower 33 1.875 1x5

Otira Transpower 11 0.694 1x2.5

Reefton Westpower 110 9.916 2x30

Blackwater Westpower 33 1.472 1x5

Ngahere Westpower 33 3.107 1x5

Arnold Westpower 33 3.357 1x5

Rapahoe Westpower 33 2.177 1x5

Ross Westpower 33 0.447 1x1

Waitaha Westpower 33 0.261 1x1

Harihari Westpower 33 1.044 1x1

Whataroa Westpower 33 0.772 1x1

Wahapo Westpower 33 3.091 1x5

FranzJosef Westpower 33 1.718 1x5

FoxGlacier Westpower 33 0.750 1x5

SpringCreek SolidEnergy 33 6.638 1x6/1x3

Globe Westpower 33 5.616 1x10

Logburn Westpower 110 1.104 1x30

Pike Westpower 33 0.761 1x20


Figure3.23showsthelocationandsizeofWestpower’s19zonesubstations.

Figure3.23-Westpower’sZoneSubstations


GLOBEGLOBE

LOGBURNLOGBURN

PIKEPIKE

DOBSONDOBSON

REEFTONREEFTON



ROSS ROSS

RAPAHOERAPAHOE

ARNOLDARNOLD

HARIHARIHARIHARI

WAITAHAWAITAHA

GREYMOUTHGREYMOUTH

HOKITIKAHOKITIKA

WAHAPOWAHAPO

KUMARAKUMARA

WHATAROAWHATAROA

NGAHERENGAHERE

Westpower's Zone Substations

1X 10 MVA Transformers


2X 20 & 2X 5 MVA Transformers







33kV Subtransmission Line

66kV Transmission Line (Westpower)

66kV Transmission Line (Transpower)

110kV Transmission Line

ASSETSCOVERED 81

Figure 3.24 shows Westpower’s zone substation atGreymouth, which houses two 10 MVA 66/11 kVtransformerbanksandwasconstructedin1977.

The latticework steel structure is unique withinWestpower’sareaandreflectsthecommonstandardsusedbyTranspoweratthetime.

TheHVbusandequipmentinthissubstationisleasedto Transpower for operation as part of the nationalgrid.

At the other end of the scale are the 1MVA 33/11kV substations used at sites such as the Whataroasubstation,showninFigure3.25.

InstallationsatHarihari,RossandWaitahausesimilarstandarddesignstotheWhataroasite.

These substations use a small transformer with an externalregulatorforeconomicreasons.

Furthermore,theywereconstructedintheearly1990sandusemodernconstructiontechniques.

Westpoweralsoownsanumberofnominal5MVAsubstations,which are similar to the Arnold construction shown in Figure3.26.

ThesesubstationsuseOn-LoadTapChangers(OLTCs),andwereconstructed between 1984 and 2003. Sites included in thisclassificationareNgahere,Arnold,Rapahoe,WahapoandFranzJosef.

All zone substationsare connected toWestpower’s SCADA system for alarmmonitoringand remote controloperation.


Zone substationsare required to transform subtransmission voltages (110kV,66 kVand33kV) to the localdistributionvoltageof11kV.TheseassetsformanintegralpartofthesupplychainandarestrategicallyspreadthroughoutWestpower’sarea.

3.7.2 PowerTransformers

Westpower has 43 power, voltage regulating and earthingtransformers installed at its zone substations (as opposedto distribution transformers, which are used in distributionsubstations).Ofthese,15arefittedwithOLTCs.

Figure3.24GreymouthZoneSubstation

Figure3.25-WhataroaZoneSubstation

Figure3.26-ArnoldZoneSubstation


Table3.27givesthegeneraldetailsofthepowertransformerpopulation.

Mostofthelargerpowertransformers(above1MVA)arethree-phaseunitsfittedwithOLTCs.

Earthing transformers areusedat zone substations connected to generating stations toprovide appropriatesourceearthingrequirements.Thesearehigh-impedanceunitsdesignedtolimitearthfaultcurrentsbyprovidingreactanceearthing.Theyalsocomprisea400Vsecondaryunittoprovidelocalservicetothesite.

3.7.3 OilContainment

Oilcontainmentfacilitieshavebeeninstalledatmajorsubstationsconstructedsince1993,includingtheDobson,Blackwater,Globe,Logburn,Pike,FoxGlacier,Reefton,ArnoldandHokitikasubstations.ThesefacilitieshavealsobeenretrofittedattheGreymouth,Kumara,Wahapo,Rapahoe,NgahereandFranzJosefsubstations.

3.7.4 Switchgear

Table3.29summarisesthepresentassetmixforthisequipmentusedinzonesubstations.

Table 3.29 - Circuit Breakers

Type 110 kV 66 kV 33 kV 11 kV Total Units

Outdoor

SF6 3 12 6 0 21

VacuumRecloser 0 0 22 16 38

Total Outdoor 3 12 28 16 59

Table 3.27 - Summary of Power Transformers


PowerTransformers

Supply3phase 3 5 18 0 26

Subtotal 3 5 18 0 26

OtherTransformers

Earthing 0 0 2 1 3

VoltageRegulating 0 0 0 14 14

Subtotal 0 0 2 15 17

TotalTransformers 3 5 20 15 43

Figure3.28-PowerTransformersAgeProfile

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 40+

Numb

er of

Trans

forme

rs

Age (Year)

110kV

66kV

33kV

ASSETSCOVERED 83

3.7.5 GeneralCondition

MostofWestpower’szonesubstationsarelessthan30yearsoldanddemonstrateaconditioncommensuratewiththeirage.ThreeoftheoldersubstationsatHarihariandFranzJosefweresubstantiallyupgradedin2010,alongwithupgradesatFox,DobsonandNgaherein2011.

AlthoughtheGreymouthzonesubstationisnow35yearsold,upgradeandreplacementworkhasbeencarriedoutoverthelast10years,includingthereplacementofthe66kVcircuitbreakersoverthelastsixyears;all66kVbusworkinsulatorsandall11kVindoorcircuitbreakersin2002;andmid-liferefurbishmentsandprotectionupgradesonbothtransformersduringthe2009/10financialyear.

Thefollowingisalistofrecentlybuiltzonesubstations:

• Anew110/33/11kVzonesubstationwasbuiltatReeftonin2005.

• Anew110/33/11kVzonesubstationwasbuiltatLogburnRoadin2007.

• Anew33/11/6.6kVzonesubstationwasbuiltatGlobein2006.

• Anew33/11kVzonesubstationwasbuiltatPikein2007.

• Anew33/11kVzonesubstationwasbuiltatBlackwaterin2009.

TheenactmentofnewlegislationintheareasofoccupationalhealthandsafetyandtheResourceManagementAct(1991)mayrequireupgradingworkatstationsintheareasoffireprotection,stationearthingandsecurityfencing.

3.7.5.1 Transformers

Becauseofthetransformers’proximitytoacoastalenvironment,corrosionoftanksandfittingsisaconstantproblem,whichneedstobeaddressedbyanongoingpaintingprogramme.

Theremainingpopulationoftransformersisnowinagenerallygoodcondition,andnomajormaintenancewillberequiredthroughouttheplanningperiod.

DissolvedGasAnalysis(DGA)performedannuallyforthelastfewyears,hasallowedWestpowertomonitortheinternalconditionofitspowertransformerpopulationanddemonstratethat,ingeneral,thereislittleevidenceofinsulationagingordeterioration.

3.7.5.2 Switchgear

Ingeneral,all switchgear is inverygoodcondition,partlyduetoWestpower’svery lowfaultduty.However,theCoopertypeKFEVacuumreclosersareprovingtobeunreliableandhavebeenresponsibleforunplannedoutageswithfaultswiththeirauxiliaryswitches,CT’sandmicroswitches.AreplacementprogrammeisinplacetoreplacetheseunitswithViper-SReclosers.CircuitbreakersattheHarihariandFranzJosefsubstationshavebeencompleted in2010,and thoseatFox,Ngahere,Dobson in2011.TheWahapozonesubstation is tobecompletedin2012/13alongwiththeArnold,Whataroa,RossandWaitahazonesubstationsinthenearfuture.Vacuumreclosers,inparticular,haveverylowmaintenancerequirementsandareexpectedtoremaininserviceforatleastthenext20years.

Table 3.29 - Circuit Breakers


Indoor

SF6 0 0 0 4 4

Vacuum 0 0 1 57 58

MetalcladPanels(BulkOil) 0 0 0 3 3

Total Indoor 0 0 1 64 65

TotalCircuitBreakers 3 12 29 80 124


AttheKumarasubstation,newSiemensSF666kVcircuitbreakerswereinstalledin1997aspartofanupgradeprojectalongwithanArevaSF666kVcircuitbreakerinstalledin2004;allareinexcellentcondition.FoursimilarArevaSF6circuitbreakerswereinstalledattheGreymouthsubstationandcompletedin2010.

Disconnectorsareconstantly subject tocorrosionofboltsandoperating linkages,andneedcontinualminormaintenancetokeepthemingoodorder.Afour-yearlypreventativemaintenanceprogrammeisinplaceforallzonesubstationstocounteractthis.

3.7.5.3 MinimumOilSwitchgear

ThelasttworemainingminimumoilcircuitbreakerswerereplacedattheGreymouthzonesubstationin2010.

3.7.5.4 OutdoorCircuitBreakers

ThispopulationhasanageprofileasshowninFigure3.30.

InternationalCouncil forLargeElectricSystems(CIGRE)studies indicatetypicalreplacementagesof40to45yearsforcircuitbreakersratedat80kVandbelow.

3.7.5.5 IndoorCircuitBreakers

Westpower’sindoorswitchgearinstallationscomprise59switchunitsintenlocationsofthefollowingtypes:

• 4SF6circuitbreakers,

• 52vacuumcircuitbreakers,

• 3bulkoilcircuitbreakers.

Inearly1999,Westpower’soldest11kVindoorswitchgearatKumarawasupgradedwiththeretrofittingofSF6circuitbreakertrucks.Alifeexpectancyof30yearsisnowexpectedfromthisequipment.

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Figure3.30-OutdoorSwitchgearAgeDistribution(ZoneSubstations)

ASSETSCOVERED 85

Apotentialreliabilityproblemwas identifiedwiththe indoorbulkoilswitchgearatGreymouthafteraseriesofcatastrophic failureselsewhere inNewZealand.Prior to this, theSO-HI typeequipmenthadachequeredhistory,sufferingfromlowinternalclearances,resininsulationbreakdownandpoorimmunitytowateringress.Furthermore,theseindoorcircuitbreakers,whilebeingrelativelyyoungatanaverageageof22years,hadbeensubjected toaheavy-dutycycle throughout their lives.Accordingly, this switchboardwas replacedwithnewvacuumcircuitbreakersduring2003.

TheonlyotherbulkoilswitchgearinuseisGECtypeBVPequipmentinstalledatRapahoein1984.ThisequipmentisdueforreplacementwithReyrollevacuumtypemetalcladswitchgearin2014/15.

Figure3.31showstheageprofileofWestpower’sindoorswitchgear.

3.7.5.6 Disconnectors

DisconnectorsareHVswitches,whichareusedtodisconnectsectionsofoverheadlineorotherprimaryplant.

Newdisconnectorsgenerallygivesatisfactoryservice,butolderdesignsareunreliableandveryoldmodelsarenowbecomingelectricallyinadequate.Theonlyeffectiveremedyisreplacementoftheseunits.

SomeoftheolderCanterburyEngineeringtypeDA2disconnectorshavealsohadproblemswithfailinginsulators,but theoccurrenceof this typeof failurehasbeen infrequentenoughnot to require a special replacementprogramme.

The four-yearly preventativemaintenance programme checks the condition of all disconnectors in all zonesubstationsandcarriesoutgeneralmaintenancetoensurethedisconnectorsarekeptinagoodconditionforoperationandhavinganormaloperationallife.

3.7.5.7 Buswork

Mostbusworksystemsconsistofconcretepolesandtubularaluminiumbuses.Theseitemsrequirevirtuallynomaintenancethroughouttheirlives.

Figure3.31-AgeDistributionofIndoorSwitchgear

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AttheGreymouthsubstation,agalvanisedsteellatticestructureisinplaceandisingoodcondition.Aconcernwiththistypeofconstructionoccurswhentheyreachanagewhererustingdevelops,whichrequirescontinuousmaintenancetocontain.Acommonproblemisadvanceddeteriorationofbolts,whichgraduallyreducestheoverall strength of the structure. Severe structural corrosion is generally found at substations located nearmarineenvironmentsandwhereindustrialworksnearbygiverisetoacorrosiveatmosphere.TheproximityoftheGreymouthsubstationtothecoastmeansthataregularinspectionprogrammewillhavetobemaintainedtocounterthis.Remedialmaintenancemayincludeperiodicpaintingofthestructure.Theolder66kVporcelaindiscinsulatorshavebeenreplaced.

Corrosionisalsoaprobleminthemetalpartsofcapandpininsulators,whichsupportbuswork.Onpostinsulatorsandstringinsulators,severerustingofthepinsleadstocrackingoftheporcelain,causingtheinsulatortofail.Also,theoldertypeofporcelainitselfhasbeenfoundtodeteriorate.Thesearethesameproblemsthataffectlineinsulators.Inthecaseofstrungbuswork,afailurecouldresultincollapseoftheconductor.Replacementwithmoderninsulatorsandgeneralupgradingofotherhardwarecomponentsisnecessarytoreducetheriskoffailures.

Crackingorspallingofconcretesupport structuresandrustingof the reinforcingsteelcanbeproblems thatrequireremedialaction.

3.7.5.8 InstrumentTransformers

Westpowerhasseveraloutdooroil-filledinstrumenttransformers,comprisingcurrent(excludingbushingtypes)andvoltageunitsinthe11kVto110kVrange.Itisestimatedthattheiraverageageisover15yearsandonlyasmallpercentageisinexcessof30yearsofage.

Generally,theyareinagoodconditionandrequireminimalmaintenance.Thecostofrefurbishmentandregularmonitoringissuchthat,inmostinstances,itismoreeconomictoreplacetheunitsiftheyfail.

Themostcommonformoffailureisduetostonedamagebyvandals,andthisishandledasrequired.

At the Greymouth substation, consideration is being given to replacing these transformers with modernequivalentsusingvandal-resistantcompositeinsulators.

3.7.5.9 EarthingSystems

Earthingsystemsinsubstationsconstructedwithinthelast15yearsweredesignedtoahighstandardandmeetcurrentindustryguidelines.

Alloftheolderzonesubstationsthatdidnotcomply,includingGreymouth,KumaraandWhataroa,underwentmajorupgradesoftheirearthingsystemscontemporaneouswithothersubstationenhancementworkcompletedwithinthelastsixyears.

AreviewiscurrentlyunderwaytochecktheimpactofEarthPotentialRise(EPR)onadjacentTelecomplant.

3.7.5.10ProtectionRelays

Most protection relays are in reasonable condition, and will only require minor inspection and servicingthroughouttheplanningperiod.

AminorproblemhasbeenidentifiedwithsealedbatteriesinCooperForm4CandForm3Areclosercontrolunits,wherebytheunitssuccumbtoahighrateofbatteryfailureafterthreeyearsofservice.Theinterimsolutionhasbeentocarryoutacyclicbatteryreplacementprogrammeofallrecloserbatteriesafterthreeyears,buteventhishasprovedineffectiveinisolatedcircumstances.Thenetresulthasbeensomelossofdiscriminationduringfaultevents,leadingtowiderpoweroutagesthanwouldhavebeenexpected.

Accordingly, all critical protection relays at zone substations will be brought up to the currentWestpowerstandard,whichincludesmodernnumericalSchweitzerprotectionrelays,overthenextthreeyears.Atthesametime,distanceelementsarenowbeingusedastheprimaryprotectionfor33kVfeeders.

ASSETSCOVERED 87

Somereplacementofprotectionrelaysduetoobsolescenceisscheduledwithintheplanningperiod.

3.7.5.11OtherStationEquipment

Batterybanksatstationswereoriginallyfittedwithautomotivelead-acidtypecells,whichtypicallygivealifeofabouttenyears.Thesehavenowbeenprogressivelyreplacedwithsealedlead-acid typebatteries,whichhaveahigher initial costbutgiveafargreaterlife(upto20years)andalsohavelowmaintenancerequirements.

Safety permit ropes and stands are also part of the stationinventories.

3.8 Distribution Substations

DRC-$2,988,413

ODRC-$2,988,413

Distribution substations generally consist of a distributiontransformerandassociatedequipmentincluding:

• 11kVdrop-outfuses,

• Lightningarrestors,

• LVfuses,

• Supportcrossarms,

• Earthingsystem.

Figure3.32showsatypicalthree-phasedistributionsubstation.

Thefittingoflightningarrestorsisnowstandardonallsubstations,andaretrofittingprogrammeoverrecentyearshasensuredthatvirtuallyeveryexistingsubstationmeetsthisrequirement.

Inadditiontotheseitems,largersubstationsratedat100kVAandabove,suchasthatshowninFigure3.33,willoftenhavethefollowingadditionalcomponents:

• Galvanisedsteelplatform,

• Maximumdemandindicator.

Because of the extremely corrosive coastal environment thatWestpowerisconfrontedwith,galvanisedsteelorCoretensteeltanksarestandardforalldistributiontransformers.

Figure3.32-TypicalDistributionSubstation

Figure3.33-Distribution

Substation>100kVA<200kVA


For large substations over 200 kVA, pad-mountconstructionisnormallyused,wherethetransformerisplacedonthegroundasshowninFigure3.34.

Extraassetsrequiredforthesesubstationsare:

• Concretepad,

• Fibreglasscover,

• HVandLVfeedercables,

• DINLVfusegear.

Table 3.35 lists the overall range and transformercapacities of the distribution substation sites, sub-totalledbynumberandtotalcapacity.

All substation data, including servicing records, arestoredintheMaximosystem.Inaddition,allsubstationsarelogicallylinkedtoindividualICPsforthepurposesofoutagenotificationsandnetworkreliabilityanalysis.


Distributionsubstationsarerequiredtobreakdownthedistributionvoltageof11,000volts,toeither400voltsor230voltssuitableforsupplyingindividualinstallations.

3.8.2 DistributionSubstationCondition

WithinWestpower’snetwork,therearearound2300distributionsubstationscomprisingsingleandthree-phaseunitsrangingfrom5kVAto1.5MVA,inthevoltagerangeof33kVto11kV.

Theconditionoftheseassetscoversthewholerangefrombeinginneedofimmediatereplacementtobrandnew.

Allmainlinesubstationshavebeenrebuiltoverthelast20yearsaspartofWestpower’srefurbishmentprogrammeandaregenerallyinverygoodcondition.Therearestillsomeveryoldsubstationsonsomespurlines,however,whichwillneedon-goingrefurbishmentthroughouttheplanningperiod.

3.8.3 DistributionTransformers

DRC - $5,996,168

ODRC - $5,996,168

Avarietyof styles exist on thenetwork, fromearlypainted steel tankunits through to the currentmoderngalvanisedtanktransformers.

Aso-calledstainlesssteeltankwasalsotrialledforashortperiod,butthepoorqualitytankmaterialexhibitedlowcorrosionresistanceandtheunitwasnolongeraccepted.

AllunitsusedinWestpower’snetworkmustnowhavegalvanisedorCoretensteeltanks,andusestainlesssteelboltstomaintainresistancefromcorrosion.

Anumberofsmalltransformerspurchasedinthe1990sareexhibitingbushinggasketdeterioration.Aprogrammeisinplacetorefurbishtheseunits.

Inaddition,allunitshaveanoff-loadtapswitchfittedtoprovidearangeof+2.5%to–7.5%(ontheHVside)forvoltageregulation.

Figure3.34-PadMountSubstation

ASSETSCOVERED 89

Twothree-phase33kV/400VunitswerepurchasedspecificallytosupplytheremoteSouthWestlandbroadcastingsiteatMtHercules;oneunitwasmaintainedinserviceandtheotherkeptasaspare.

Single-phase33kV/400VunitssupplycustomersintheSouthWestlandareawhoareremotefromWestpower’sdistributionnetwork,butclosetotheHokitika-Harihari33kVline.Thecustomersacceptthatnosparewillbeprovidedfortheseunits.

Table3.35summarisesthedistributiontransformersbytypeandsize.

Table 3.35 - Distribution Substation Transformers Number and Capacity

KVA Inside Building Concrete Pad-Mounted Pole-Mounted

1PH 2PH 1PH 2PH 1PH 2PH

1 0 0 0 0 1 0

5 0 0 0 0 19 1

7.5 0 0 0 0 27 0

10 0 0 0 0 280 11

15 0 0 0 1 570 59

16.5 0 0 0 0 0 1

20 0 0 0 0 33 24

22.5 0 0 0 0 1 0

25 0 0 0 0 2 21

30 0 4 1 11 52 557

35 0 0 0 0 0 1

40 0 0 0 0 1 0

50 0 0 0 3 0 179

66.6 1 0 0 0 0 0

75 0 1 0 4 0 85

100 4 1 1 25 1 72

125 0 1 0 1 0 13

150 0 0 0 7 0 31

175 0 0 0 0 0 1

200 0 1 0 81 0 27

250 0 1 0 1 0 3

300 0 2 0 44 0 6

325 0 1 0 0 0 0

500 0 5 0 40 0 5

750 0 0 0 8 0 0

1000 0 3 0 6 0 0

1250 0 0 0 2 0 0

1500 0 0 0 0 0 0

2000 0 0 0 2 0 0

Subtotal 5 20 2 236 987 1097

Total 2347


Figures3.36and3.37showtheageprofileandkVAprofileofthedistributiontransformers,respectively.

Figure3.36-AgeProfileofTransformers

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Figure3.37-KVAProfileofDistributionTransformers

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ASSETSCOVERED 91

Table3.38summarisesthepopulationofdistributiontransformers.

3.8.3.1 AssetJustification

Distribution transformers are the key componentof adistribution substation, and the justification for theseassetsisthesameasfordistributionsubstationscoveredinSection3.8.1.

3.8.3.2 DistributionTransformerCondition

Themajorityoftransformersarelessthan30yearsold,withamedianageofjustover20yearsandanegligiblenumberbeyond50yearsold(3%).Thiscoincideswiththeperiodofsystemdevelopmentinthe1960sandearly1970s.

Transformersaregenerallyingoodcondition,althoughforsomeoftheolderpaintedtransformers,refurbishmentand/orreplacementisrequiredratherthangeneralmaintenance.

Aproblemhasbeenidentifiedwithdeteriorationofbushinggasketsonsmallerunitsinthesix-tenyearagebracketwheretheseareinstallednearthecoast.Itappearsthatthesurfaceleakagecurrentattacksthegasketmaterial,eventuallyleadingtofailureofthegasketandwateringress,resultinginelectricalfailureofthetransformer.Toaddressthisissue,arefurbishmentprogrammehasbeguntoreplaceat-riskgaskets,andtoinstallreplacementbushingswithapartialsemiconductivecoatingaroundtheflangearea.

3.8.4 DominionDrop-OutFuses

Asastandarddesignpolicy,aDominionDrop-Out(DDO)fuseunitfusesallthedistributiontransformers,whicharefeddirectlyfromanoverheadHVline.

Upuntil1996,allfuseunitswereoftheECGoughtypemanufacturedlocallyformanyyears.AmajorreliabilityproblemwiththeseunitscausedWestpowertomovetotheABChancestyleofDDO.However,theseunitswerefoundnot topivotopenproperlywhenexposed toacorrosiveenvironment foraperiodoftime.AEMtypedrop-outsimportedfromAustraliawerethenimplemented,withtheGoughandChanceunitsbeingreplacedasscheduledmaintenancetakesplaceondistributionsubstations.FurtherproblemswiththeAEMunitsmeantthatacompletetechnicalreviewwasundertaken,andSandCunitsarenowbeingpurchased.

3.8.5 EarthingSystems

TheElectricityRegulationssuggestthatallsubstationearthingsystemsshouldbebroughtuptoastandardof10Ω.InWestpower’ssituation,becauseoftheveryhighsoilresistivitythatisoftenencountered,adesiredearthresistanceof10Ωisnotpracticallyachievableinallcases.

Nevertheless,theregulationsrequirethatearthingsystemsbetestedeveryfiveyears,andWestpowerisnowaddressingthisissueinearnest.Tomeettherequirements,aprogrammeofregularfive-yearlytestshasbeeninstituted.

Basedonexperience,itisexpectedthatduringthetestingphase,severalsubstandardearthinginstallationswillbeidentifiedthatarecapableofbeingpracticallyupgraded.Aprogrammeofupgradingtheseearthingsystemsusingdrivenrodsandextracopperconductorswillfollowdirectlyfromtheearthtestingexercise.

Table 3.38 - Summary of Distribution Transformers

PrimaryVoltage

Type 66 kV 33 kV 11kV Total Units

PowerTransformers

Distribution1phase 0 3 991 994

Distribution3phase 0 4 1349 1353

TotalTransformers 0 7 2340 2347


3.9 MV Switchgear

DRC - $1,468,901

ODRC - $1,468,901

Thisclassofequipmentincludes:

• Regulators,

• Disconnectors,

• 11kVcircuitbreakers,

• Reclosers,

• Sectionalisers,

• Ringmainunits,

• 11kVdryfuseunits.

These are not installed at zone substations. (MV switchgearwithinzonesubstationsisincludedinthatclassification.)

Lineregulatorsareinstalledonlong11kVlineswithsignificantloads near the end. Westpower has such installations atLongfordCorner(nearKokatahi),Cronadun(northofReefton)andtheHaupiriarea,anda33kVregulatoratHarihari.

Ingeneral,disconnectorsarestandardtwo-threepostunitsmadebySchneider(ex-CanterburyEngineering),butDA2type.SomeunitsarefittedwithCEBreakload-breakheads.

Westpowerhasusedarangeofreclosingequipmentoverthelast50years,buthasnowstandardisedontheuseofG&WViperStvacuumreclosersandENTECloadbreakswitchesforallfutureinstallations.

AtypicalreclosercanbeseeninFigure3.39.

Smallnumbersofold11kVcircuitbreakersarestillinuseasdistributionsubstationbreakers.

TheringmainunitsaremainlyReyrolleorABB“Safelink”type,SF6SDinsulatorsorABBoilinsulators,andarealllessthan25yearsold.ThereisoneremainingAndelectringmainunit.SomeHazemeyerdry-typeequipmenthasalsobeeninstalledinthenetwork,butitsuseisnotwidespread.AvariantofthisequipmentmadebyKronehasbeenphasedoutandreplacedbecauseofreliabilityconcerns.

Table3.40summarisesthepresentpopulationofMVswitchgear.

Fig3.39-TypicalRecloser

Table 3.40 - MV Switchgear

Type 33 kV 11kV Total Units

Disconnectors 3 388 391

LoadBreakDisconnectors 0 20 20

MotorisedDisconnectors 11 12 23

VacuumRecloser 1 37 38

LoadBreakSwitch(ENTEC) 0 14 14

RingMainUnit 0 44 44

GangedExpulsionDrop-outs 0 34 34

TotalUnits 15 549 564

ASSETSCOVERED 93


Theseassetscoveradiverserangeofdevices,butgenerallyincludeswitchesofvarioustypesthatareusedtoprotectandsectionalisethenetwork.Intheeventofafaultonthenetwork,fuses,reclosersandsectionalisersareneededtoisolatethefaultedsectionsafelyandquickly,andtherebymaintainsupplytoothercustomersonunfaultedsectionsofthenetwork.Thedevicesarealsonecessarytoisolatesectionsoflinetoallowmaintenancetobecarriedout.

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Fig3.41-MVSwitchgearAgeProfile

02468

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3.9.2 MVSwitchgearCondition

MostofWestpower’sMVswitchgear isrelativelymodernand ingoodcondition.However,arecentseriesoffaultsontheAndelect0utdoortyperingmainunitshasgivencausetomostoftheseunitsbeingreplacedoverthelastfiveyearsusingnewSF6units.WestpowernolongerusesSeriesIAnderlectoil-insulatedABBringmainunitstocloseontoexpectedfaults.

Otherexceptionstothisarethelargeanddiversepopulationofdisconnectors,whichwillneedtobemanagedonanasset-widebasis(seeSection3.9.6).

3.9.3 Regulators

Amovingcoilthree-phaseregulatorwasinstalledatLongfordCornerandisabout30yearsold.The2MVAunitwasprovingtobeunreliableanddifficulttofindreplacementpartsfor.Theunitwasduetobereplacedinthe2012/13financialyearbutfailedinAugust2011.Thiswasreplacedbytwosingle-phaseunitsandreturnedtoserviceinSeptember2011. It isplannedtobringtheregulatorsiteuptoanacceptable level inthisfinancialperiod.

Intheearly1980s,sixCooperSR32single-phase32stepregulatorswerepurchasedforFoxandKokiri.ThethreeinstalledinFoxweremovedtothenewsubstationsitefromCookFlatRoadin2003.ThethreeatKokiriweremovedtoHarihariwhenthe33/11kVsubstationwasdevelopedthereandKokiri’sfunctionwasreplacedbytheArnold33/11kVsubstation.In2007,oneoftheFoxunitsfailed(lightningwassuspected)soanewCooperunitwaspurchasedtoreplaceit.WiththeincreasingloadatFox(presentpeakatabout50A),the100Aregulators’capacitywaslimited.Theseregulatorswerereplacedwith200Aunitsin2009.

ThelineregulatoratCronadunwasanoldtap-changingunitpurchasedsecond-handfromTranspower.Thisunitreachedtheendofitseconomiclifeandrequiredconstantmaintenance.Sparepartswerehardtosourceandtheunitwascostlytomaintain.Thisregulatorwasreplacedwithrefurbished(ex-Fox)100Aunitsin2009.TheSR32sareinrelativelygoodcondition,thoughthepaintworkwillneedattentionsoon.

At the end of the 2003 dairy season, it was identified that the Haupiri area needed a voltage regulator tocompensatefortheongoingdevelopments.AsetoftwoGE100AregulatorswereboughtandinstalledneartheoldMiersMillsite.

TheSouthWestlandPotentialSupportprojectwascompletedin2005,involvinginstallationofa10MVA33kVvoltageregulatoratHarihari.ThiswaspurchasedsecondhandfromAurora(ex-Queensberry).ItsfunctionistoprovidesupporttotheSouthWestlandareaforperiodswhenWahapoisnotgenerating.Thiswillberemovedfromservicewhen66kVisreturnedtoSouthWestlandfromHokitika.

Eachof theRoss,WaitahaandWhataroasubstationshasa1MVA inductionregulator installed.Theyareallsimilarandwerepurchasedsecond-handfromTranspower.Theirmanufacturedatesareunknownbuttheyarethoughttobeinexcessof60yearsold.Twohavehadpaintworkrefurbishedlatelyandthethirdisprogrammedforrepainting.Theseallworkwellatpresentbutwouldnotbeworthfixingifamajorfaultoccurredwithinthem.Theirconditionandoperationisbeingmonitored.

3.9.4 CircuitBreakers

Agedindoorbulkoilcircuitbreakerssupplyingindoordistributiontransformershavereachedtheendoftheireconomiclives.Thesewillbereplacedwithfusedswitchunitsormodernequivalentsoverthenextfiveyears.

3.9.5 Pole-MountedReclosers

Thereare38pole-mounted11kVreclosersatvariouslocationsthroughoutthenetwork.Thirty-sevenofthesereclosersarecontrolledremotelybySCADA.ThesereclosersareacombinationofCoopertypeKFMEandViperSTreclosers.

ASSETSCOVERED 95

Over the last two years, Cooper KFE type reclosers have been progressively replacedwithG&WViper STreclosers,protectedbymoderndigitalSEL651Rprotectionrelays.Thisprojectwascompletedinthe2011/12financialyear.

3.9.6 RemoteControlledMotorisedDisconnectors

For some time,Westpower has been having trouble sourcing a reliablemotor drive unit for themotoriseddisconnectors.Westpowerhasnowdevelopedahydraulicactuator.Thesearegraduallybeingfittedtovariouslocationsonthenetwork.

Also TheDulmisonmotor driveunits had alsobecomeunreliable. Thesehavebeen gradually replacedwithENTECloadbreakswitches,withthelastremainingDulmisonunitstobereplacedthisfinancialyear.

3.9.7 Disconnectors

Themostdiverseassetsarethedisconnectors,whichareconstantlypronetocorrosiondamage.Mostmainlinedisconnectorshavebeenreplacedwithnewunitsduringtherecentfeederupgradeprogramme.Afive-yearlypreventativemaintenanceprogrammeisinplacetoensurealldisconnectorsaremaintainedtoagoodandsafeoperatingcondition.

Asoldertwo-insulatormodelswithout“flicker”or“wiping”arcinghornsarenotsuitableforuseonmainlines,aprogrammeforreplacementhasbegun.Otherthree-insulatormodelsarealsounsuitableonsomelinesbecauseofsystemloadings.Aneffortwillbemadetoidentifyandreplacetheseunitswithinthenextfiveyears.

Other,newerunitsdonothavesufficientcurrentbreakingcapacitybecauseofindividuallineloadings.Theonlysolutioninthiscaseistofitsuitableloadbreakheads.

3.10 SCADA, Communications and Protection

DRC - $233,333

ODRC - $233,333

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This includes all communications equipmentand radio repeater sites, as well as vehicle-mounted equipment and the SCADA plantincludingthemasterstationinthecontrolroom.Anyequipmentinstalledatzonesubstationshasalreadybeencoveredunderthatarea.


TheSCADAandcommunicationsnetworksareessential to allowWestpower tomonitor andoperateitsnetwork.Intheeventofafault,thesesystems allow safe isolation of the defectiveplant and also fast restoration of supply to asmany customers as possible. The system isalso required for Westpower to monitor therealtimeperformanceoftheasset.Protectionsystems are required by legislation to ensuresafeisolationoffaultedequipment.

3.10.2 SCADASystem

Westpower’smasterSCADAstationisbasedupontheRealFlex6productsuppliedbyDATACoperatingonIBMServerhardwarerunningaQNXNeutrinooperatingsystem.

TheHuman-MachineInterface(HMI)isaWindows-basedclientsrunningonstandarddesktopnetworkedPCs.StorageofhistoricaldataisviaaMySQLDBMS.ThemainSCADAenginewasupgradedtothelatestversionofRealFlex(6.5)in2010.

TheoperatorHMI fordataandcontrol isdoneviaFlexviewsoftware,which is run in thecontrol roomonastandardWindowsXPPCsfittedwiththree22-inchLCDs.ThisgivestheoperatortheabilitytonotonlyviewSCADAdatabutalsosimultaneouslyuseanyotherPCsoftware.TheabilityofFlexviewtorunonPCsallowstheSCADAinformationtobeviewedfromalmostanywherewithinWestpower’scomputernetwork.

Figure3.44showstheSCADAmasterstationlayout.

The information viewed within Flexview is captured byRealFlexwhichrunsonapairofdedicatedHPProLiantDL140IntelXEONServers located in thesecureserver room,onebeingtheonlineserver,whiletheotheractsasahotstandbyin case of hardware failure. These servers run the latestversionof RealFlex and runon anoperating system calledQNXNeutrinoRTOS,whichissimilartoUNIX,andprovidesanetworkoperatingsystemdesignedforreal-timeapplicationsuchasSCADA.

AllvitalSCADAequipmentispoweredviatheUninterruptiblePowerSupply,whichprovidesaneight-hourbackupincaseofamajorpoweroutage.Furthermore,athree-phasegeneratorhas been installed to provide power to all equipmentincluding the Uninterruptible Power Supply (UPS), furtherextendingthisback-upperiodifrequired.Figure3.45showsthethree-phasegeneratorused.

Figure3.44SCADAMasterStation

Figure3.45-3-PhaseGenerator

ASSETSCOVERED 97

3.10.3 RemoteTerminalUnits

RealFlexhas theability tocommunicatewithmanydifferent typesofRemoteTerminalUnits (RTU)andfieldequipmentsuchasprotectionrelaysandPLC’sviamostoftoday’sstandardcommunicationprotocols.

Forsmallerzonesubstationsandremotesitessuchasreclosersandautomateddisconnectorsinthedistributionnetwork,AbbeySystemsTopcatII,TopCat,ModuLinkandMicroLinkRTUsareinstalled.

TheTopCatIIisasmallunitwithfixedI/OandalsohastwolocalcommunicationportstoconnecttoaPLCorprotectionrelay,whichprovidesadditionalcontrolandequipmentstatusdata.

Afeatureoftheseunitsisthepre-emptivecommunicationsprotocol,whichallowstheRTUtobepolledveryinfrequently,whilesimultaneouslyprovidingtheabilityfortheRTUtoupdatethemasterstationwheneverachangeofstateoccurs.

AbbeyRTU’suseWestpower’sVHFspeechradiochannelstocommunicatewiththemasterstation.

3.10.4 CommunicationSystem

Westpower communications network provides vital SCADA, telephony and tele-protection services for theWestpower distribution network, Transpower transmission network, TrustPower and Pike River Coal. Thecommunicationnetworkisamixoffibre,VHFRadio,UHFradioanddigitalradio.

3.10.5 CommunicationCables

Afibre-opticcablerunsfromtheserverroomintheTainuiStbuildingtotheGreymouthsubstation.Thisfibrelinkisusedforspeech,SCADAandsurveillancemonitoringoftheGreymouthsubstation.

AsecondfibrecablerunsfromtheserverroomtoChapelSt.ThisfibrelinkisusedforSCADAandoffsitecomputerbackups.

3.10.6 VHFNetwork

TheVHFspeechnetworkisanextensivesystemusedbyWestpower,ElectroNetServicesandTrustPower(WestCoastGeneration).

Asvehiclesarereplaced,regularremovalandreinstallationofexistingmobilesetstakesplace.

3.10.7 UHFNetwork

TheUHFnetworkisusedexclusivelytoprovidecommunicationpathsfortheagingDatatermscurrentlyinstalledattheWhataroaandWahaposubstations.ThisequipmentisalmostexclusivelyTait300seriesequipment,withasmallamountof800seriesequipmentinstalledinrecentyears.RepeatersitesarelocatedatPaparoa(nearGreymouth),MtHercules(nearHarihari)andtheWhataroasubstation.Mainspowerisreticulatedtoallofthesesites.

3.10.8 DigitalNetwork

Thedigitalradionetworkconsistsofamixtureofradiotechnologies,mostlyconsistingoflicensedpoint-to-pointradiofrequencies.DigitalradiolinksprovideInternetProtocoland,whererequired,serialandvoicechannelstoallmajorWestpowersubstations.CurrentsitescoveredbythedigitalnetworkaretheGreymouth,Dobson,Hokitika,Reefton,Ngahere,Arnold,Rapahoe,Kumara,Globe,Logburn,BlackwaterandPikesubstations.

3.10.9 Protection

Protectionsystemsaremainlyrestrictedtozonesubstations,withthenotableexceptionoflinereclosers,whichuseinternalproprietaryprotectionrelays.


AsWestpowerusedtohaveusedCooperPowerSystemtypereclosersasthestandard,theprotectioninvolvedisoftenthatsuppliedwiththereclosers.TheseoftencompriseamixtureoftheKFEorKFMEreclosersandFXA/FXBprotectioncontrollers.

Duetothehighmaintenancecostsandunavailabilityofsparepartsforthesereclosers,Westpowerhasdecidedtodevelopaprogrammetoreplacethemby2013/2014.ThenewrecloserapprovedbyWestpowerisaG&WViperSTcontrolledbyaSEL651Rprotectionrelay.

Allprotectionunitsarelessthan25yearsoldandareofsolidstateconstruction.

AllotherprotectionsystemsareincludedinSection3.7.

MostoftheprotectionassetsownedbyWestpowerarerelatedtooverheadlineprotection,andthemajorityoflinesareprotectedbyovercurrentandearthfaultrelays.

The33kVand11kVfeederprotectionequipmentisgenerallyofthesameageastheswitchgear(at11kV,theprotectionisoftenanintegralpartofthecircuitbreaker).

SchweitzerEngineeringLabsprotectionrelaysarenowusedforallnewzonesubstationfeeders.

3.10.10CommunicationSystemCondition

AllVHFcommunicationequipmentisinexcellentconditionafteracompletereplacementprogrammethattookplaceintheearly1990s.Tait2000seriesequipmentisnowusedthroughoutthenetworkandrarelygivestrouble.

TheexistingUHFanaloguesysteminSouthWestlandwillbemaintainedforseveralyears.

3.11 Ripple Injection Plants

DRC - $180,000

ODRC - $180,000

Westpowerownsfourrippleinjectionplants,withoneeachatReefton,Greymouth,HokitikaandDobson.

Theseplantsareusedforloadcontrolpurposesaswellasprovidingtariff-switchingsignalsforusebyretailers.

Retailersalsousethissystem,bycontractualarrangementwithWestpower,toshiftloadfromhigh-costtolow-costperiods,providedthatloadcontroloperationalrequirementsarenotcompromised.

HokitikaandGreymouthhaveEnermetSFU-K303series120kVAinjectionplants installed,whileDobsonandReeftonhaveEnermetSFU-K203series80kVAplants.Allplantshaveassociatedinjectiontransformers,couplingcellsandHVcircuitbreakers.Inallcases,theinjectionplantandmajorcouplingcellcomponentsarehousedinsideabuilding.

TherewasonlyoneinjectionpointatGreymouthfrom1982until1996,whenthesupplementaryplantswereinstalled.Duringthisperiod,thesystemreliedontheTranspower66kVtransmissionsystemforasignalpathtooutlyingareas.

All plants are controlled remotely by the SCADA loadmanagement system and locally via Abbey PowerlinkInjectioncontrollers.

Thefouron-lineplantsrunsynchronously,i.e.theyareabletoinjecttheidenticalripplewaveformateachofthefoursitesatthesametime.GPStechnologyhasmadethispossiblebyprovidinganaccuratetimebaseateachsitewhichisperfectlysynchronisedinfrequencyandphasewiththeotherbases.

Astand-alonerippleplantistobeinstalledatWahapozonesubstationin2011/12.Thiswillbeinstalledintheexisting shedandwill beusedonoccasion toprovide ripple control to SouthWestlandareawhenWahapogenerationisrunningislandedfromtheremainderofWestpower’snetwork.

ASSETSCOVERED 99

ThisplantwillconsistofthebestavailablepartsfromthedecommissionedPlesseyTRseries75kVAplantsatReefton,GreymouthandHokitika.


RippleinjectionplantsareakeypartofWestpower’sdemandsidemanagementstrategyandareusedtosendripple signals to receivers in customers’ premises that allow interruptible loads suchaswaterheating tobeswitchedonoroff.Thisiscriticaltomaximiseuseofexistingassetsandavoidunnecessaryassetexpendituretocoverunnecessarilyhighpeakdemands.

3.11.2 RippleControlCondition

Westpowersoldallofitsripplerelaystothenewincumbentretaileron31March1999alongwithexclusiveuseofchannelsexistingatthattime.Therippleinjectionplantswereretainedforthepurposeofloadcontrolaswellastoprovidealoadswitchingservicetoretailersundercontract.

Allrippleinjectionplantsareeitherneworingoodorder,aswouldbeexpectedfromtheirageprofile.

3.12 Optimised Assets

Other than the following asset optimisation, there has beennoother overdesign or over-investment in theWestpowernetwork.Table3.46summarisestheoptimisedassets.

TheHokitikatoHarihari66kVlinewaspurchasedfromTranspowerin2001buthasonlybeenrunningat33kVsince1993,whenaphysicaloptimisationtookplace.AnewgenerationschemeatWaitahainSouthWestland,tentativelyplannedfor2016/2017,willinvolverecommissioningthelineata66kVvoltagelevel,andupgradingtheexistingconductorandtheconnectedsubstationsfrom33kVto66kV.

ThePunakaikifeederwasbuiltat33kVinthemid-1990swhenanillmeniteminewasplannedforthearea,butthisprojecthassubsequentlybeenshelved.Thelineisnowonlyrequiredtooperateat11kV.Notwithstandingthis,thecoastalenvironmentinwhichthislineoperatesischaracterisedbyextremesaltmistpollution,andtheadditionalcreepagedistanceaffordedbythe33kVinsulatorsemployedisregardedasbeneficialandreducesthenumbersoftransientfaultsinthearea.

TheWahapoandFranzJosef6MVAtransformerswerepurchasedsecond-handforaverylowpricefollowingtheclosureoftheTarakohecementworksinthelate1980sandtheovercapacitynowapparentismoretodowithoptimalcapitalinvestment(i.e.agoodbargain)thanevidenceofperceived“gold-plating”.Inanycase,theloadatFranzJosefisforecasttorequirethefull6MVAcapacitybytheendoftheplanningperiod.

Table - 3.46 Optimised Assets

Asset Asset Type Physical Rating Optimised Rating

WahapoZoneSubtransformer ZoneSubstation 6MVA 4MVA

FranzZoneSubtransformer ZoneSubstation 6MVA 5MVA

PunakaikiFeeder DistributionLine 33kV 11kV

Hokitika-HarihariLine SubtransmisisonLine 66kV 33kV


On19November2010adisasteroccurredat thePikeRiverCoalMine,andthishas resulted inasignificantreductionatthesite.AtthetimeofpreparingthisAMP,thefuturerequirementforelectricitysupplyatthemineislargelyunknownandthismaywellresultinstrandedassetsthatmayrequirefutureoptimisation.

3.13 Generation

Westpowercurrentlyownsnogenerationplant,butisplanningtore-enterthismarketsegmentthroughajointventurewithotherpartnerstoconstructa7MWhydroschemenearHariharicalledtheAmethystscheme.A20MWschemenearWaitahaisalsobeinginvestigated.

Customer-embeddedgenerationontotheWestpowernetwork(greaterthan1MW)isasshowninTable3.47.

TrustPowerownsallofthisgenerationplant,whichisconnectedtoWestpower’s11kVnetwork.

3.14 Load and Customer Characteristics by GXP

AsdiscussedinSection3.2,WestpowerissuppliedbysixGXPsspreadthroughoutitsarea.ThefollowingdiscussestheloadcharacteristicsandlargeconsumersineachoftheareassuppliedbytheseGXPs.

3.14.1 Reefton(RFN110)

TheReeftonGXPsuppliesloadfromLyellinthenorth,BerlinsintheeastandBlackwatertothesouth.

Theloadischaracterisedmainlybydairyfarminganddomesticload,althoughthereissomesmallcommercialloadinthetownofReefton,alongwithsomemining.

Table3.48showsthebulkcustomerssuppliedfromthisGXP.

3.14.2 Atarau(ATU110)

Asnotedabove,thisGXPwascommissionedin2007tosupplythenewPikeRivercoalmine.

Apartfromafewsmallfarmsanddomesticdwellingsinthearea,thisGXPisdedicatedtothesupplyofthemine.Withtherecentminedisaster,thefutureprospectsforthisGXPareunknownatthisstage.

3.14.3 Dobson(DOB033)

DobsonsuppliestheGreyValleyfromBlackwaterinthenorthtoPunakaikiinthewest,tonorthofGreymouthinthesouthandRotomanuintheeast.

Table 3.48 - Bulk Customers from Reefton GXP

Bulk Load Load Type Load Size

SolidEnergy-TerraceMine UndergroundCoalMine 75kW

OceanaGoldLimited-ReeftonGoldProject OpenCastGoldMine 5300kW

Table 3.47 - TrustPower Embedded Generation

Site Owner Year in Service KW Generated Connection Point Connection Voltage

ArnoldPowerStation TrustPower 1932 3,000 Arnold 11kV

DillmansPowerStation TrustPower 1928 3,500 Dillmans 11kV

KumaraPowerStation TrustPower 1928 6,500 Kumara 11kV

McKaysCreek TrustPower 1931 1,100 McKaysCreek 11kV

Wahapo TrustPower 1991 3,000 Wahapo 11kV

KaniereForks Truspower 1931 600 KaniereForks 11kV

ASSETSCOVERED 101

ThisGXPcoversawideareawithamixoffarming,industrial,residentialandholidayhomeload,butrelativelylittlecommercialload.ItwasoriginallyconstructedtosupplythetownofGreymouthandthecoalminingloadinthelowerGreyValleyandRunangaareas,butwassituatedtoofarfromGreymouthtownshiptosupplythegrowingloadthere.AseparateGXPwasconstructedinGreymouthinthelate1970s.


3.14.4 Greymouth(GYM066)

TheGreymouthGXPsuppliesthetownofGreymouthandthesatellitetownshipsofCobdenandBlaketown,aswellasSouthBeach,RutherglenandParoatothesouth.

Aswouldbeexpected,theloadismainlydomestic,commercialandlightindustrial,withasmallbutgrowingloadresultingfromincreasedtourismtothearea.


3.14.5 Kumara(KUM066)

TheKumaraGXPismainlyrequiredtoprovideaGIPforTrustPower’s10MWKumarahydroscheme,butalsosupplieslocalloadintheareafromGladstoneinthenorthtoJacksonsintheeasttoDuffersinthesouth.Whenthegenerationisnotrunning,apeakexportdemandoflessthan2MWisprovidedfromthissubstation.

Apartfromthesignificantgeneration,theloadtypeismainlyfarmingandruralresidential,althoughthereisonesignificantindustrialloadconnectedtothisGXP,asshownbelowinTable3.51.

3.14.6 Otira(OTI011)

TheloadatOtiraistotallyisolatedfromotherGXPs.Apartfromasmallhotelandafewhousesandbaches,themajorityoftheloadconsistsofthefanmotorsfortheOtiraTunnel.ThisisdetailedinTable3.52below.

Table 3.50 - Bulk Customers from Greymouth GXP


Kingsgate-KingsgateHotel-Greymouth Hotel 300kW

Westfleet-WestfleetFishProcessing-Greymouth FishProcessingPlant 230kW

FreshChoice-Greymouth Supermarket 220kW

MonteithsBrewery-Greymouth Brewery 200kW

NewWorld-Greymouth Supermarket 310kW

TheWarehouse-Greymouth RetailStore 200kW

CoastHealth-GreymouthHospital-Greymouth Hospital 410kW

IPL-Plywood-Gladstone TimberProcessor 650kW

Table 3.49 - Bulk Customers from Dobson GXP


SolidEnergy-SpringCreekMine-Dunollie UndergroundCoalMine 6500kW

RoaCoalMine-Roa(nearBlackball) UndergroundCoalMine 1200kW

StillwaterLumber-StillwaterSawmill TimberMill 700kW

CMP-PhoenixMeatWorks,Kokiri Abattoir 1360kW

Table 3.51 - Bulk Customers from Kumara GXP


IPL-PlywoodMill-Gladstone TimberProcessor 550kW

Table 3.52 - Bulk Customers from Otira GXP


TranzRail-Otira FanLoad 600kW


3.14.7 Hokitika(HKK066)

TheHokitikaGXPsuppliesthetownofHokitikaandallareassouthofthereasfarasLakeParinga,some200kmaway.

Theloadisamixofdairyfarming,residential,commercial,lightindustrialandlargeindustrial.SouthofWhataroa,theloadispredominantlydrivenbythetouristcentresofFranzJosefandFoxGlaciers.


3.15 Voltage Support Systems

Westpowerregularlyusesvoltageregulatorsthroughoutitsdistributionnetworkandhasalsoinstalledregulatorsinits33kVsubtransmissionnetworkatHariharitosupportthevoltageinSouthWestlandwhenTrustPower’sWahapogeneratorisnotrunning.Althoughthisregulatorisgenerouslyrated,itwasboughtsecond-handforapricewellbelowmodernreplacementcostandcouldbereplacedbyasmallerunitifithadtobereplacedinthefuture.

Table3.54showsthescheduleofvoltageregulatorsinstalledinWestpower’snetwork.

Inadditiontovoltageregulators,anumberofHVcapacitorshavebeenstrategicallyinstalledthroughoutthe11kVdistributionnetwork.ThisimprovestheapparentpowerfactoroftheloadsseenfromTranspower’sGXPs,resulting in improvedvoltage regulation throughout theWestCoast. It also improves the voltageprofiles inindividual11kVfeedersleadingtoimprovedcapacityandreducedlosses.

Capacitorshavebeeninstalledatvariouslocationsthroughoutthe11kVnetwork.Thereareatotalof16capacitorsites,varyinginsizefrom0.3Mvarto1.2Mvar,withatotalcapacityof11.0Mvar.Allofthesecapacitorlocationsarelessthantenyearsold,andareacombinationofpad-mountedandpole-mounted.AlloftheaboveareunderWestpower’soperationalcontrol.

Mostof the capacitors installed in thenetworkarefixed, asopposed to switchedbanks, although switchedcapacitor banks exist inGreymouth,Hokitika, Franz Josef and Shantytown. The Franz Josef and ShantytowncapacitorsbanksareLV.

Becausecapacitorscanabsorbripplesignals,dependingonthesizeofthecapacitorandthesystemconfiguration,theyareofteninstalledwithseparateblockingchokestoavoidthisproblem.

Table 3.54 - Voltage Regulators

Regulator Site Voltage Size

Cronadun(northofReefton) 11kV 2250kVA

LongfordCorner(eastofHokitika) 11kV 2000kVA

Haupiri(eastofDobson) 11kV 2000kVA

Harihari 33kV 10000kVA

Table 3.53 - Bulk Customers from Hokitika GXP


WestlandDairy-HokitikaDairyFactory-Hokitika MilkProcessingFactory 8200kW

WestcoLagan-RuatapuSawmill-Ruatapu TimberMill 880kW

SilverFernFarms-HokitikaVenisonFactory-Hokitika VenisonAbattoir 250kW

NewWorld-Hokitika Supermarket 200kW

WestlandMotorInn-FranzJosef Hotel 330kW

ASSETSCOVERED 103

Table3.55detailsthe11kVdistributioncapacitorsinstalledonWestpower’snetworkandthezonesubstationthattheyareconnectedto.

Inaddition,a7MvarcapacitorbankatGreymouthsubstationanda19.2MvarbankatHokitikasubstationareunderTranspower’soperationalcontrol.

3.16 Westpower Mobile Substation

Westpower’smobilesubstationwasdevelopedtoprovideaneffectivemeansofmaintainingelectricitysuppliestoareasservedbyzonesubstationswithsingletransformers.Essentially,itisaself-containedzonesubstationonwheels,andisratedat33/11/3.3kVand8/10MVA.

The33and11kVcablesarestoredonreelsandrolledouton-sitetoconnecttothelocal33and11kVnetworks.Alloftheswitchgear,SCADA,controlandprotectionsystemsareonboardandreadytogoatshortnotice.

Thissubstationcanbeusedto:

• Reducerestorationtimeintheeventofaforcedoutageofatransformeratasingletransformersubstation;

• Provideforatemporaryoraugmentedsupplytoanareaneartothesubtransmissionsystemwhenanewbuildisnotwarrantedforshortdurationpeaksorloads;

• Allow for extended maintenance outages at substations without interrupting supply to consumers forsignificantperiods.

ThisisoneofonlythreesuchsubstationsthatWestpowerisawareof,withtwooftheseintheSouthIsland.ThisinnovationhasimprovedsecurityandreliabilityinWestpower’snetwork.Sofar,ithasbeenusedonseveraloccasions,savinglossofsupplyorextracostfromtemporaryhireofgenerators.

Table 3.55 - Capacitors

Location Zone Substation Voltage Capacity

SouthHighway6-Hokitika Hokitika 11kV 1000kVAr

KaniereTram Hokitika 11kV 1000kVAr

Strongman Rapahoe 11kV 1000kVAr

FoxGlacier FoxGlacier 11kV 500kVAr

ReeftonSaddle Reefton 11kV 500kVAr

Kokiri Arnold 11kV 1200kVAr

Wahapo Wahapo 11kV 500kVAr

SolidEnergyBathHouse Rapahoe 11kV 1000kVAr

Punakaiki Rapahoe 11kV 300kVAr

Rotomanu Arnold 11kV 500kVAr

Kokatahi Hokitika 11kV 1000kVAr

Kotuku Arnold 11kV 500kVAr

Haupiri Arnold 11kV 300kVAr

Gladstone Greymouth 11kV 500kVAr

Shantytown,Rutherglen(Switched) Greymouth 0.4kV 500kVAr

FranzJosef(Switched) Franz 0.4kV 500kVAr


Figure3.56showsthecompletedmobilesubstation.

A number of substations have beenmodified to accommodate themobile substation and thismodificationprogramme will continue throughout this planning period. The zone substation sites prepared for mobilesubstationconnectionsofarareArnold,Dobson,Ngahere,Rapahoe,FranzJosef,FoxGlacier,Whataroa,Globe,HarihariandBlackwater.

TheWaitahazonesubstationsiteistobepreparedformobilesubstationconnectionthisfinancialyear.

3.17 Substation Buildings

Westpowerhasanumberofbuildingsofdifferenttypeslocatedarounditsnetwork.Somehousesubstationsandsomehousecontrolequipment.Table3.57liststhebuildingswithintheWestpowernetwork,theirlocation,purposeandtypeofconstruction.

BuildingmaintenanceisanimportantpartofmaintainingtheconditionofassetswithintheWestpowernetwork.Theconditionofthebuildingswasassessedinthe2004LifelinessurveyreportforWestpowerandanumberofissueswerehighlighted.Theseincludedcheckingforthepresenceofreinforcingsteelintheearlypermanentbuildingsandensuringthatthesandwichpanelbuildingswererestrainedsufficientlytomitigatetheeffectsofearthquakeloads.

Azonesubstationbuildingclimatecontrolprogrammehasseenairconditioningunitsinstalledatvariouszonesubstations.Overthelastthreeyears,unitshavebeeninstalledatReefton,Globe,Blackwater,Pike,Logburn,Rapahoe,Greymouth,FranzJosefandHokitika.Thesehavebeeninstalledtoprovideaconstanttemperatureinzonesubstations,allowingforamorestableenvironmentforallequipmentinzonesubstationcontrolrooms.

Figure3.56-Westpower’sMobileSubstation

ASSETSCOVERED 105

Table 3.57 - Summary of Substation Buildings

Building Location Purpose Materials of Construction

ArnoldSubstation Storageandoffice Lighttimberframed

BadgerLaneSubstation Switchgear Permanent

DobsonSubstation Controlequipment Transportablesandwichpanels

FoxSubstation Controlequipment Transportablesandwichpanels

FranzJosefSubstation Controlequipment Lighttimberframed

GreymouthSubstation Switchgear&controlgear Permanent

HarihariSubstation Controlequipment Transportablesandwichpanels

HokitikaSubstation Switchgear&controlgear Permanent

MawheraQuaySubstation Switchgear&controlgear Permanent

RapahoeSubstation Switchgear&controlgear Lighttimberframed

RossSubstation Controlequipment Transportablesandwichpanels

WahapoSubstation Controlequipment Lighttimberframed

WaitahaSubstation Controlequipment Transportablesandwichpanels

WhataroaSubstation Controlequipment Lighttimberframed

DobsonSubstation Switchgear&controlgear Lighttimberframed

ReeftonSubstation Switchgear&controlgear Permanent

LogburnSubstation Switchgear&controlgear Permanent

NgahereSubstation Controlequipment Lighttimberframed

HarihariRegulator Controlequipment Transportablesandwichpanels

GlobeSubstation Switchgear&controlgear Transportablesandwichpanels

PikeSubstation Switchgear&controlgear Transportablesandwichpanels

BlackwaterSubstation Switchgear&controlgear Transportablesandwichpanels


4.0 LEVELS OF SERVICE

4.1 Introduction

InordertoproperlymanagethedeliveryofservicetoWestpower’sconsumers,itiscriticalthatappropriateKPIsaredevelopedtomeasuretheperformanceofthenetworkobjectively,andtoensurethattheseKPIscanbeappliedconsistentlyacrossthenetworkandovertime.Furthermore,theseKPIsmustberelevanttotheservicebeingdeliveredandreadilyunderstandablebyinterestedstakeholders.

OncetheKPIsarecreatedandreportingmechanismsareputinplacetomonitorthemroutinelyonanongoingbasis, performance targets can be developed to set clear benchmarks against which the service deliveryperformanceofthebusinesscanbeassessed.Thishasatwofoldbenefitofproviding:

• Ameansofmonitoringtrendsovertimeandmeasuringjusthowwellthebusinessisdeliveringservicetoitsconsumers;

• Awayofcreatingrealisticgoalsforthefuturethatprovideaclearbasisfortheprovisionofwelltargetedreliabilitymaintenanceorenhancementprogrammes.

ThetargetscreatedthroughthisprocessneedtobeconsistentwithWestpower’sbusinessstrategiesandassetmanagementobjectives,which,inturn,arederivedfromtheassetmanagementpolicythatformsthekeylinkagebetweenthecorporatedirectionofthebusinessandtheassetmanagementfunction.

Overtime,theKPIsandtargetswillcontinuetoberefined,basedonhistoricalperformanceandstakeholderrequirements.Inaddition,thetargetsmustreflectwhatisrealisticallyachievable,giventhecurrentconditionofthenetworkandthefinancialexpenditurecapabilityofthebusiness.

Furthermore,byadoptingthisapproachofsettingtargetsandthenmeasuringperformanceagainstthetargets,itispossibletoobjectivelyassessthesuccessofprogrammesdesignedtoenhancetheservicedeliveryperformanceoftheassetandthenmakeadjustmentstoprovideoptimumlong-termoutcomes.

Thetargetlevelsofservicemaygenerallybesubdividedintothefollowingtwomainareas:-

• Consumer-orientedperformancetargets;

• Othertargetsrelatingtoassetperformance,assetefficiencyandeffectiveness,andtheefficiencyoftheELBactivity.

ThissectionexplainsthetargetlevelsofservicethathavebeenchosenbasedontheKPIsdeveloped.Historicalperformanceagainstthesetargetlevelsisprovided,alongwithcommentaryonthereasonsforanyunderlyingtrendsorsignificantperturbations.Finally,ajustificationisprovidedforcurrentandfuturetargetlevelsofservicebasedonconsumer,legislative,regulatory,stakeholderandotherconsiderations.Includedinthisjustificationisadiscussionofhowstakeholderneedswereascertainedandtranslatedintoservicetargetlevels.

4.2 Customer-Orientated Performance Targets

Thekeyperformanceindicescommonlyusedthroughouttheelectricityindustrytoassesscustomer-orientedperformanceareSAIDIandSAIFIasdefinedinIEEEStandard1366:2033.

These are the same indices as used by all ELBs. By adopting an approach consistent with this standard,benchmarkingofWestpower’sperformanceagainstotherELB’sissupported.

This sectiondescribeshistoricalperformanceof thenetworkaccording to these indicesandcompares themwith related targets currentlymandatedby the targetedcontrol regimeunder thecontrolof theCommerceCommission.

NETWORKDEVELOPMENT 107

AsWestpowerisnowexemptfromsuchregulation,ithasdevelopedmoremeaningfultargetsthatarespecifictoparticularcustomergroupsandtypesofoutages,asdiscussed in thefollowingsections.ThesehavebeenderivedfromhistoricalperformanceaswellasexpectationsoftheimpactofparticularimprovementinitiativesthatWestpowerhasundertakenoverrecentyears.Westpowerdoes,however,stillcomeundertheElectricity(InformationDisclosure)Requirements2008andmuststilldiscloseindustrystandardperformanceindices.

4.2.1 ExtremeEvents

AsWestpower’sareaissubjectedtoextremeweathereventsfromtimetotime,itisimportanttodisaggregatetheKPIsintobaselinevaluesthatreflecttheunderlyingperformanceofthebusiness,andextremeeventvaluesthatresultfromenvironmentalexternalitiesthatarebeyondthereasonablecontrolofWestpower.Thebaselinevalues(i.e.thoseexcludingmajorevents)arethekeyindicatorsusedconsistentlythroughoutthisplan,andthereaderneedstoexercisecautionincomparingthesenormalisedstatisticswithinformationpublishedundertheinformationdisclosureregime,whichincludesallevents.

ThemethodofachievingthenormalisationofthemeasuredvaluesisbasedonIEEEStandard1366:2003,whereaMajorEventDay(MED)isdefinedandthenusedasathresholdtoexcludestatisticsthatrelatetoamajorevent.

Thisprocessusedto identifyMEDs is termedthe“Betamethod”. Itspurpose is toallowmajorevents tobestudiedseparatelyfromdailyoperationand,intheprocess,tobetterrevealtrendsindailyoperationthatwouldbehiddenbythelargestatisticaleffectofmajorevents.

AMEDisadayinwhichthedailysystemSAIDIexceedsathresholdvalue,TMED.TheSAIDIindexisusedasthebasisofthisdefinitionsinceitleadstoconsistentresultsregardlessofutilitysize,andbecauseSAIDIisagoodindicatorofoperationalanddesignstress.EventhoughSAIDIisusedtodeterminetheMEDs,allindicesshouldbecalculatedbasedonremovaloftheidentifieddays.

IncalculatingdailysystemSAIDI,anyinterruptionthatspansmultipledaysisaccruedtothedayonwhichtheinterruptionbegins.

TheMEDidentificationthresholdvalue,TMED,iscalculatedattheendofeachreportingperiod(typicallyoneyear)foruseduringthenextreportingperiodasfollows:

1. Collect values of daily SAIDI for five sequential years ending on the last day of the last completereporting period. If fewer than five years of historical data are available, use all availablehistoricaldatauntilfiveyearsofhistoricaldataareavailable.

2. Only those days that have a SAIDI/day value will be used to calculate the TMED (do not includedaysthatdidnothaveanyinterruptions).

3. Takethenaturallogarithm(ln)ofeachdailySAIDIvalueinthedataset.

4. Findαtheaverageofthelogarithms(alsoknownasthelog-average)ofthedataset.

5. Findβthestandarddeviationofthelogarithms(alsoknownasthelog-standarddeviation)ofthedataset.

6. ComputetheMEDthreshold,TMED,usingthefollowingEquation:

TMED=e(α+2.5β)

7. AnydaywithadailySAIDIgreaterthanthethresholdvalueTMEDthatoccursduringthesubsequentreportingperiodisclassifiedasaMED.

ActivitiesthatoccurondaysclassifiedasMEDsareexcludedfromthemeasuredstatistics.

Westpowerhas calculatedaTMEDbasedonall outages recordedduringafive-yearoutageperiod coveringApril2004throughtoMarch2009andthishasyieldedaSAIDIfigureof18.14systemminutes.Accordingly,thereportedstatisticshavebeennormalisedbyexcludingalleventsthathadaSAIDIvalueinexcessofthisfigure.*

HistoricalperformancehasbeenbasedonusingthesamenumberfortheTMEDinallyears,asopposedtousingarollingfive-yeardataset,asthereissomequestionaroundtheaccuracyofdatacollectedpriorto2003.*NotethatthisisslightlydifferentfromtheCommerceCommissionapproach,wherethestatisticfortheMEDiscappedtoamaximumvalueratherthanexcluded.Thepurposeofthisservicelevelperformanceexerciseisbestservedbyexcludingthevaluessothatthestatisticaleffectsofmajoreventsondailyoperationsarecompletelyremoved.


Figure4.1-AreasDefinedWithinWestpower’sNetwork-North

Legend

OHLINE BY TERRAIN

TERRAIN

REMOTE

RURAL

URBAN


Figure4.2-AreasDefinedWithinWestpower’sNetwork-South

Legend

OHLINE BY TERRAIN

TERRAIN

REMOTE

RURAL

URBAN


4.2.2 BreakdownbyLocation

Tofurtherdisaggregatetheperformancedataandcreatemoremeaningfultargetsagainstwhichperformancecanbeassessed,thedataarebrokendownbythefollowinglocations:

• Urban–includingmajortownsandisolatedareaswithurbancharacteristics(e.g.undergrounddistribution);

• Rural–generallyfarmingareasoutsideofmajortowns;

• RemoteRural–areasof SouthWestland southofHokitikabutexcluding local feedersofRoss,Waitaha,HarihariandWhataroa.

ThedefinitionusedforRemoteRuralisslightlydifferentthanthatusedbytheCommerceCommission(i.e.morethan75kmfromthenearestbase),asallofSouthWestland,extendinguptoaround150kmsouthofHokitika,isfedbyasingle33kVfeeder.Analysisisgreatlysimplifiedbygroupingthisareatogetherfor33kVfaultsonly,asamixtureofareasareaffected.Localfaultsaretreatedasrural,asdiscussedabove.

Figure4.1and4.2overleafshowsthedefinedareas.

4.2.3 PlannedvsUnplannedPerformance

Inadditiontotheforegoinganalysisofthedata,namelyexclusionofMEDsanddisaggregatingthereliabilitydatabylocation,afurtherrefinementhasbeenappliedbysplittingtheservicelevelsintoplannedandunplanned(fault)categories.Therationalebehindthisapproachisthattherearedifferentdriversforeachtypeofservicelevel.

Plannedoutagesresultfromscheduledmaintenanceactivitiesthatareoftenpartofaproactivemaintenanceapproachtoimprovetheoverallperformanceofthenetworkoverthelongterm.Inaddition,consumersarenotifiedwellinadvanceofaplannedoutageandareoftenabletotakestepstominimisetheirexposuretotheeffectsoftheoutage.Inviewofthis,plannedoutagesarelessdisruptivethanunplannedoutages.Inaddition,theyaremoreacceptabletoconsumersinviewoftheperceivedlonger-termbenefits.

Ontheotherhand,unplannedoutagescancausesignificanteconomicdamageto industrialandcommercialconsumers,whileresidentialconsumersareoftensignificantlyinconvenienced.Accordingly,consumersarelesstolerantofthistypeofoutageandseparatetargetsneedtobedevelopedthatrecognisethedisparitybetweenthecustomerdamagefunctionsfromeachoftheseofoutages.

The data included in this section of theAMP allow for this disaggregationwherever possible, including thecomparisonofhistoricalperformanceagainsthistoricaltargets.


4.2.4 HistoricalPerformance

ThehistoricalfiguresforSAIDIandSAIFIshowninTables4.3and4.4,andFigures4.5to4.8,havebeennormalisedbytheremovalofMEDs.

Table 4.3 - Planned and Unplanned SAIDI (Urban, Rural and Remote Rural)

2006-07 2007-08 2008-09 2009-10 2010-11

URBAN

Planned 19.11 8.05 19.56 26.97 12.88

Unplanned 26.34 33.12 36.21 31.95 35.41

Total 45.45 41.17 55.77 58.92 48.29

RURAL

Planned 30.54 30.32 21.42 16.68 31.48

Unplanned 48.7 52.08 54.91 67.78 62.13

Total 79.24 82.4 76.33 84.46 93.61

REMOTERURAL

Planned 6.00 6.09 2.74 10.19 2.55

Unplanned 23.95 20.86 43.96 56.59 44.03

Total 29.95 26.95 46.70 66.78 46.58

GrandTotal 154.64 150.52 178.80 210.16 188.48

PlannedActuals 55.65 44.46 43.72 53.84 46.91

PlannedTargets 40.00 40.00 40.00 55.00 60.00

UnplannedActuals 98.99 106.06 135.08 156.32 141.57

UnplannedTargets 70.00 70.00 70.00 95.00 115.00

Table 4.4 - Planned and Unplanned SAIFI (Urban, Rural and Remote Rural)

2006-07 2007-08 2008-09 2009-10 2010-11

URBAN

Planned 0.100 0.030 0.080 0.089 0.054

Unplanned 0.440 0.400 1.140 0.289 0.877

Total 0.540 0.430 1.220 0.378 0.932

RURAL

Planned 0.200 0.100 0.120 0.057 0.104

Unplanned 1.430 0.660 1.110 0.561 0.791

Total 1.630 0.760 1.230 0.618 0.895

REMOTERURAL

Planned 0.020 0.100 0.020 0.034 0.014

Unplanned 0.350 0.120 0.650 0.930 0.784

Total 0.370 0.220 0.670 0.964 0.798

GrandTotal 2.540 1.410 3.120 1.960 2.624

PlannedActuals 0.320 0.230 0.220 0.180 0.172

PlannedTargets 0.250 0.250 0.250 0.340 0.680

UnplannedActuals 2.220 1.180 2.900 1.780 2.452

UnplannedTargets 1.000 1.000 1.000 1.360 1.310


Figure4.5-PlannedSAIDIProfileforLastFiveYears

0

5

10

15

20

25

30

35

2006-07 2007-08 2008-09 2009-10 2010-11

Min

ute

s L

ost

Year

URBAN

RURAL

REMOTE RURAL

Figure4.6-UnplannedSAIDIProfileforLastFiveYears

0

10

20

30

40

50

60

70

80

2006-07 2007-08 2008-09 2009-10 2010-11

Min

ute

s L

ost

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RURAL

REMOTE RURAL

Figure4.7-PlannedSAIFIProfileforLastFiveYears

0.0000

0.0500

0.1000

0.1500

0.2000

0.2500

2006-07 2007-08 2008-09 2009-10 2010-11

Min

ute

s L

ost

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URBAN RURAL REMOTE RURAL


ForthereasonsdiscussedinSection4.2.2,ruralareasappeartohavepoorerperformancethanremoteruralareas,butthisismainlyduetodifficultiesindisaggregationofthefaultdataforSouthWestland.

4.2.5 PerformanceTargets

Tables4.9to4.11belowshowthespecificperformancetargetssetbyWestpowerfortheplanningperiodinquestion.

TherationaleforsettingthespecifictargetlevelsisdiscussedinSection4.4.

Inadditiontothegenerictargetsdiscussedabove,additionaltargetshavebeendevelopedaround:

• Themaximumlengthofoutage;

• Thenumberofextendedfaultsthatconsumerswillbeexposedtoineachtypeofarea.

Thesetargetsareconstantthroughouttheplanningperiodandtheperformance.

Table 4.9 - SAIDI Targets Projected Forward 10 Years

2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

PlannedTargets 49 49 49 49 49 49 49 49 49 49

UnplannedTargets 128 128 128 128 128 128 128 128 128 128

Totals 177 177 177 177 177 177 177 177 177 177

Table 4.10 - SAIFI Targets Projected Foward 10 Years

2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

PlannedTargets 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22 0.22

UnplannedTargets 2.11 2.11 2.11 2.11 2.11 2.11 2.11 2.11 2.11 2.11

Totals 2.33 2.33 2.33 2.33 2.33 2.33 2.33 2.33 2.33 2.33

Figure4.8-UnplannedSAIFIProfileforLastFiveYears.

0.0000

0.2000

0.4000

0.6000

0.8000

1.0000

1.2000

1.4000

1.6000

2006-07 2007-08 2008-09 2009-10 2010-11

Min

ute

s L

ost

Year

URBAN

RURAL

REMOTE RURAL


4.3 Other Targets

Asmallnumberofkeyassetperformanceandefficiencytargetshavebeenchosenthatprovidethereaderwithaclearunderstandingofthewaythebusinessisperforming.Itisfeltthatthisisabetterapproachthantoincludea large number of less significant and often conflicting performance targets thatwould create unnecessaryconfusion.

Relevant standard performance and efficiency targets, as defined in the Electricity (Information Disclosure)Requirements2008havebeenchosenforinclusioninthisAMP.Theseare:

• OperationalExpenditure(OPEX)ratio(OPEX/systemassetsreplacementcost),

• CapitalExpenditure(CAPEX)ratio(CAPEX/systemassetsreplacementcost);

• Renewalratio(assetrenewal-refurbishmentOPEXandCAPEX/depreciation),

• Distributiontransformercapacityutilisation;

• Faultsper100circuitkm(disaggregatedbyvoltageandconductortype(overhead/underground).

TheseindicatorswillbemeasuredinamannerthatisconsistentwiththedefinitionsintheElectricityDistribution(InformationDisclosure)Requirements2008.

Table4.12belowshowsthehistoricalperformanceoftheseindicesandfuturetargetedperformance.

BasedonthehistoricalperformancedisclosedinTable4.12andthetargetsforthefinancialratiosalreadydefinedinWestpower’sSCI,thetargetsintable4.13areprovidedfortheplanningperiod.

AKPIintermsofassetperformanceisthefaultsper100kmindex.AscanbeseeninTable4.12,thisvaluewasrecentlyresettoreflectthevaluesachievedoverthelastfiveyearsmorerealistically.

Table 4.11 - Other Customer Service Targets

Service Area Customers Affected Performance Target

RestorationofSupply

UrbanAreas 95%offaultsrestoredwithinthreehoursofnoti-fication

RuralAreas 95%offaultsrestoredwithineighthoursofnoti-fication

RemoteRuralAreas(SouthofHokitikaexcludinglocal11kVFeedersofRoss,Whataroa,Waitaha,andHarihari)

95%offaultsrestoredwithin12hoursofnotifica-tion

CustomerOutageImpact

UrbanCustomersNomorethantwoplannedoutagesperannumNomorethantwounplannedoutagesperannum(for

90%ofcustomers)

RuralCustomersNomorethantwoplannedoutagesperannum

Nomorethanfourunplannedoutagesperannum(for90%ofcustomers)

RemoteRuralCustomersNomorethantwoplannedoutagesperannumNomorethaneightunplannedoutagesperannum

(for90%ofcustomers)

Table 4.12 - Historical and Future Targeted Performance

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Projected

DistributionTrans-formerCapacity

Utilisation31% 30% 30% 31% 31% 30% 30% 30% 30% 30% 30% 30% 30% 30% 30%

Faultsper100kmCircuitLength 3.91 7.39 4.69 5.16 5.35 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30 5.30


4.4 Justification for Targets

In general, the targets reflect historic performance while consumer engagement indicates a high level ofsatisfaction with existing service levels. In addition, consumers have indicated an unwillingness to pay theadditionalcostsnecessaryifservicelevelsweretobesignificantlyimproved.

Ingeneral,thetargetsreflectfeedbackfromconsumersregardingcurrentandfutureperformance,alongwithhistoricperformanceachievedtodate.

ThefinancialratiotargetsarebasedonfiguresdisclosedtoandacceptedbythetrusteeownersofWestpoweronbehalfoftheconsumersasdisclosedintheSCI.

Thesehavebeencarefullyderived,basedon:

• Historicalperformance,

• Stakeholderrequirements,

• Industrybestpractice,

• Assetrenewalrequirements.

TheWCEPT considers the SCI each year, andeither approves thedocumentor requests further changes. Inconsidering a draft SCI, theWCEPTwill often take independent advice, which this allows benchmarking ofperformanceagainstsimilarcompanies.Suchscrutinyformsthebasisofaregularandongoingformalreviewthatensuresarobustoutcomethatisdesignedtomeetourconsumers’needs.

ThetargetsshowninTable4.13abovearebasedonWestpower’sten-yearbusinessplan,whichisbuiltupfromtheAMPforecasts.TheCAPEXratioandtherenewalratiodropovertimeasmuchoftheolderassetswillsoonbereplaced,leadingtoalowerlevelofsteadystatereplacement.

Assuch,thefinancialtargetsrepresentaclearmandatethatWestpowerisboundtoreflectinitsinternalplanningprocesses.

TheSAIDIandSAIFItargetsarebasedonafive-yearrollingaverageofperformancetodate.Thisisfelttobeavalidapproachbecausethekeydriversforthesestatisticsareexternal,subjecttolong-termweatherpatterns.Atthesametime,Westpowerwantstoensurethatperformancedoesnotdegrade;arollingaverageachievesthis.

4.4.1 ConsumerEngagement

Westpower carries out a consumer satisfaction survey every two years, with themost recent survey beingcompletedinDecember2009.

Thefollowingisanextractofthesummaryfromthismostrecentsurvey:

Thisreportsummarisestheviewsandpreferencesobtainedfromthefollowingtwosamplespace:

• Westpower’s25largestconsumers,

• Arandomsampleof497massmarketconsumerspro-ratedfromsixGXPareas.

Table 4.13 - Future Performance of Efficiency Targets Stated in Section 4.2

2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

OPEXRatio 6.60% 7.00% 7.30% 7.30% 7.30% 7.30% 7.30% 7.30% 7.30% 7.30%

CAPEXRatio 4.90% 2.00% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50% 1.50%

RenewalRatio 39% 29% 35% 35% 35% 35% 35% 35% 35% 35%


Thenumberofcompletedmassmarketsurveyswasonly30%,whichisslightlylowerthanthepreviousWestpowersurvey(38%)andalsolowerthansimilarsurveysperformedforotherELBs.Somereasonablyclearpatternshaveemerged,asfollow:

• Themostimportantaspectofelectricitysupplyiscontinuityofsupply.

• Thesecondmostimportantaspectofelectricitysupplyisrestorationofsupply.

• Thethirdmostimportantaspectofelectricitysupplytomassmarketconsumersistimelyshutdownnotices,withthetop25consumerspreferringnoflickerorsurgesastheirthirdpreference.

• MassmarketconsumersrateWestpower’sperformanceinthemostimportantaspectofcontinuityasverygood,withaslightskewtowardsexcellent.

• MassmarketconsumersrateWestpower’sperformanceinthesecondmostimportantareaofrestorationasbeingverygood,withaskewtowardgood.

• In the third most important aspect of shutdown notices, mass market consumers rate Westpower’sperformanceasverygood,withaskewtowardgood.

• Massmarketconsumershaveexpressedanobviouspreference(76%)forcontinuingtopayaboutthesamelinechargestoreceiveaboutthesamereliability.However,asmallerbutnonethelessdistinctminority(15%)expressedapreferenceforpayingslightlymoretoreceiveslightlymorereliability.

• Largeconsumersexpressedadistinctpreference(76%)forpayingaboutthesametoreceiveaboutthesamereliability,withonlythreeconsumersindicatingawillingnesstopayslightlymoretoreceiveslightlymorereliability.

• Consumerengagementindicatesahighlevelofsatisfactionwithexistingservicelevels.Inaddition,consumershaveindicatedanunwillingnesstopaytheadditionalcostsnecessaryifservicelevelsweretobesignificantlyimproved.

Asaresultofthisstrongcustomermandate,WestpowerwillstrivetoatleastmaintainitsSAIDIandSAIFIlevelsatrecentlevels.

4.4.2 HistoricalReliabilityPerformance

Westpowerhasalreadytakenanumberofstepstoimprovenetworkperformanceoverrecentyears,usingallreadilyavailablemeansandtosuchanextentthatfutureimprovementsareexpectedtobeincrementalatbest.Moreover,futureperformancewillcontinuetobestronglyinfluencedbyexternaldriverssuchasstorms,whichwillfaroutweighandeffectivelymaskanyimprovementsgainedthroughadditionaltechnologicalimprovements.

Afteranumberofyears,duringwhichtheactualSAIDIandSAIFIstatisticssignificantlyexceededthemandatedtargetsundertheprice/qualityregime,anopportunitywastakentoresetthetargetlevelstovaluesthatmoreaccuratelyandrealisticallyreflecttheexpectedperformancemovingforward.

Accordingly,after someconsideration, itwasdecided toadoptfive-year rollingaveragevalues forSAIDIandSAIFI,thusensuringthatthereisnooveralldegradationinservice,whilealsoprovidinganachievabletargetthatcontractorsandsystemoperationstaffcanconfidentlyaimfor.Tofurtheravoidunnecessaryvolatility,WestpowerwillcontinuetousefiguresthatexcludeMEDs,bothinthetargetsandtheactualperformanceindicesdisclosed.

Thetargetfiguresfor2011to2020arethusbasedontheaveragefiguresachievedoverthefive-yearperiodfrom2006to2010.Inaddition,asthereisnolikelihoodofsignificantstepimprovementsinthefuture,aflatprofilehasbeenprojectedthroughouttheplanningperiod,althoughthiswillcontinuetoberevisedeachyearsothatanyincrementalimprovementsgainedarereflectedinfuturetargets.


Thisisimportant,asWestpowerwillcontinuetoseekoutcost-effectivereliabilityenhancementsolutionswherethesecanbeshowntoofferanopportunityforrealbenefits,suchastheforthcominginstallationofagroundfaultneutraliserattheGreymouthsubstation,whichsuppliesover30%ofWestpower’sconsumers.Byusingafive-yearrollingaverageforSAIDIandSAIFI,anymaterial improvementresultingfromthis innovationwillbecapturedinfutureforecastsandmaybecomeajustificationforprogressivelyextendingthistechnologytoothersubstations.

AscanbeseeninTable4.14,themaincausesforunplannedoutageshavebeentreecontactandhighwinds/rain. This is predicted to improve slowly over the planning period as initiatives such as better segregationof the network (more reclosers,more reliable replacement reclosers) and an improved focus on vegetationmanagementbegintotakeeffect.

TwofeedershavebeenidentifiedwithhighunplannedoutageSAIDIminutes:

Hokitika-Harihari33kVcircuit(HKK1012)

Acurrentprojectinvolvesthestagedreplacementofthisasset.Theconstructionhasbeendesignedtoallowforfutureupgradingbyensuringthatlineinsulationandclearancesaresuitablefor66kVoperation.Reliabilitywillbeprogressivelyimprovedwiththestagedcompletionofthisproject.

The33kVdisconnectorsatRoss,WaitahaandHarihariarebeingautomatedwithSCADAcontroltoreducefaultisolationswitchingtimesandrestorationofsupply.

Table 4.14 SAIDI CAUSE BREAKDOWN April 10 to March 11

DescriptionYear to Date

Events Time (Minutes) % of SAIDI

PlannedOutages 114 47.32 25%

Vehicle 2 0.22 0%

Wind/Rain 24 12.39 7%

Lightning 2 0.23 0%

Animal 0 0.00 0%

EarthmovingEquipment 2 0.34 0%

EquipmentFailure 22 18.76 10%

Deterioration 1 0.06 0%

Unknown 18 32.01 17%

HumanError 2 3.71 2%

Tree 34 68.54 36%

Overload 0 0.00 0%

BirdStrike 4 1.98 1%

SaltDeterioration 0 0.00 0%

Vandalism 1 0.04 0%

Snow 0 0.00 0%

Other 1 0.13 0%

Flood 1 2.44 1%

Fire 1 0.31 0%

UnplannedOutagesSubtotal 115 141.16 75%

TOTALS(PLANNEDANDUN-PLANNED) 229 188.48 100%


FOX1Feeder

TheFoxCB1feedersuppliesanareafromFoxGlaciertoParinga.Becauseoftheremotenessofthearea,faultisolationswitchingtimescanbe long.To reduce fault isolationtimes,a sectionaliser (ENTECswitch) is tobeinstalledintheBruceBayareatosegregatefaultsautomatically.

4.5 Stakeholder Needs

InordertosetreasonablesecuritystandardtargetsforWestpower’scustomersthatarecompatiblewithenduserexpectations,appropriateresearchmustbecarriedout.

The needs of electricity users have changed greatly over the last ten years with the rapid introduction oftechnologyintothedomesticmarket.Appliancesfromvideorecorderstobreadmakersandhomecomputersarenowcommonplace inmanyhomes,andhavegreatly increasedthesensitivityofhouseholders topoweroutagesandminor interruptions.Consultationwiththe25 largestcustomershasconfirmedthatadoptionofProgrammableLogicControllers(PLC)andSCADAbyindustryhasreducedtolerancetofleetingevents–rotatingandthermalplantthathassufficientinertiatocontinuethroughafleetingoutagewillnowprobablybetrippedwhenitscontrollerlosespowerforacycleortwo.

CustomerdamagefunctionreportsrecentlycarriedoutonbehalfoftheElectricityCommissioninsupportofTranspower’sapplicationfortheWCGUPshowedthatevenshortoutagescanresultinseveralhoursofproductiondowntimeformajorprocess-basedconsumers.Accordingly,solutionsthatprovideforcontinuousconnectiontothenetworkratherthan“change-over”schemesarepreferred.

PartofWestpower’s role is tomaintainanefficientandreliableelectricitydistributionnetworkontheWestCoast.Inthiscontext,“efficiency”and“reliability”arerelativetermsthataresubjecttopersonalperceptions.In turn, these perceptionsmust be viewed from the customer’s viewpoint, whichmust be actively sought.Westpowerintendstoliaisecloselywiththeenergyretailerstodeterminetheexpectationsoftheircustomersandtoquantifytheseintermsofdesirablereliabilityindices.


5.0 NETWORK DEVELOPMENT

5.1 Introduction

Thissectionoutlinesthenetworkdevelopmentplanrequiredtomaintain,enhanceanddeveloptheoperatingcapabilityofthesystem.

ThemainfocusofthissectionistheuseofConditionBasedMaintenance(CBM)andriskmanagementtechniques(asdescribedinSection9)toscheduletheprojectsrequiredtomeetthereliabilitytargetsandremainwithinthebudgetarylimitationsimposedforthisplanningperiod,andtoappropriatelyschedulenetworkdevelopmentprogrammesforfutureperiods.

5.2 Planning Criteria and Assumptions

Futureloadprojectionisadifficulttaskandisbasedonacomplexmultivariateenvironment.

Someofthedriversthateffectfutureloadinclude:

• Climaticconditions,

• Economicactivity,

• Commodityprices,

• Foreignexchangerates,

• Majorsteploadincreases/decreases.

Arelativelywarmwinterhasasignificantimpactonwinterheatingloadsand,asaresult,hasamajoreffectontheannualpeakload.

Overalleconomicactivity,whichis,tosomeextent,alsolinkedtogoldpricesandcoalmarkets,hasafilterdowneffectonelectricityconsumption.Thiscantakeeffectslowlyoverthemediumterm.

With the relatively small overall demand,major step load changeshave a great impact on systemdemand.Unfortunately,thesearealsothemostdifficulttopredictorquantify,astheydependoninvestmentdecisionsfrommajorindustries.Historically,finalcommitmentsontheseprojectshavebeendeferredtoaverylatestage,ofteninvolvingsignificantlastminuteloadrevisions.ThisleavesWestpowerinadifficultsituationfromaplanningperspective.

ThePikeRiverminedisaster,whichoccurredon19November2010,hasresultedinamajorsteploaddecreaseofsome6MWforWestpower.Thetrickledowneffectonthelocaleconomyisstillsomewhatuncertain.However,loadforecastprojectionsfor2012/2013havebeenmoderatedforthepurposesofloadforecasting.Atthisstage,ithasbeenestimatedthatloadfromthePikeRiverminewillcomebackonstreaminaroundtwoyears’time;however,thisisonlytentativeatthisstageandtheforecastswillbereviewedonceafinaldecisionismadeonthefutureofthemine.

Acarefulandrigorousapproachhasbeentakentodevelopingfutureloadprojectionsbasedonhistoricaltrends,availableinformationandestimatesonfuturechanges.ALoadwatchspreadsheetisakeydatareceptacleusedtostoreinformationforlaterinputintothedemandforecastingprocess.Theloadgrowthprojectionswereusedasabasisfordeterminingthelikelytimingofthoseprojects,whicharejustifiedbyloadgrowth.

Firstly, load trendsateachGXPover theprevioussevenyearsarestudied to try to identifyhistoricbaselinechanges.Theeffectsofknownsteploadincreasesareextracted,leavingtheunderlyinglong-termhistoricloadprofile.

BasedonGXPdataandgeneralknowledgeofthelocaleconomyandotherdriversdiscussedabove,anestimateismadeofthelikelyfuturetrendinloadgrowthonaGXPbasis.Thisthenprovidesanewbaselineforfurtherwork.


5.2.1 EnhancementandDevelopmentCriteria

This activityoutlinesworkwhich is planned toenhanceanddevelop the system. Thismeans increasing thecapacityofthesystemandeliminatinganylimitationsinorderto:

• Providemoreload,

• Enhancevoltageregulation,

• Improvesecurityandreliability.

It includes projects (at specific sites) and programmes of relatedwork. Network limitationswhich relate tosystempeakloadingare:

• Acceptablestandardsofreliabilityofsupplycannotbemaintained.

• Theacceptablenetworkratingofplantandequipmentcannotbemaintained.

• Thethermalratingofplantandequipmentisexceeded.

Additionalnetworklimitationsare:

• Thefaultratingofequipmentisexceeded.

• Theageofequipmentrendersitscontinueduseoperationallyunsafeoruneconomic.

• Continuedoperationof theexistingnetwork isnoteconomic,e.g. small conductor sizesorhigh reactivepowerflowscausingexcessivelosses.

Theprocessforevaluatingnetworklimitationsissystematicandcoversallitemsofequipmentandallcircuits.Particularattentiontoallthemostcommonlimitationsisrequired(refertoTable5.1below).

5.2.2 ReliabilityandSecurityofSupply

5.2.2.1 SecurityGuidelines

Thesecurityguidelinesarethebasisforanalysisandfordeterminingthefutureperformanceofthedistributionsystem.Table5.2outlinessomeofthesecurityguidelinesfordistributionplanning.ThelevelsofsecuritythatcurrentlyexistsforeachzonesubstationaresummarisedinAppendixC.

Table 5.1 - Common Network Limitations

Equipment Common Limitations

Transformers Rating,ageingconditions,tappingrange,voltageregulation.

Switchgear Rating,age,insulation,faultrating,buszoneprotection,sparefeederunits,sensitiveearthfaultprotection.

Cables Rating,age,leaks,faultyjoints,longrepairtime,faultrating.

OverheadLines Rating,physicalconditions,reliability,losses,clearances,voltagedrops,faultrating.

Table 5.2 - Security Guidelines for Distribution Planning

Load (MW) Basic Security Level Transmission Circuits Busbars Transformers

Lessthan10 n Onecircuit Onebusorbussection.1x3-phaseunit,ifbackedupfromalternativesupply

points

Above10 n-1 Twocircuits Twobusbarsorbussections.

2x3-phaseunits,firmsup-plyofpeakdemandusinganyshort-termoverload

capacity.


With regard to thedesignof systemchangesornetworkextensions,dueconsideration ismadeof the levelof security required for the connected consumers. An industrial customer, for instance,may require a non-interruptiblesupplyforaspecificmanufacturingprocess,whilstadomesticcustomercantolerateoccasionalsupply interruptions. Specific criteria for interruption and quality of supply may need to be developed forindividualcustomersbothfordesignconsiderationandcommercialcontractualobligations.

Table5.3showstheminimumsecuritylevelsforWestpower’sdistributionsystems.

Customerswhoarepreparedtoenter intocommercialagreementscanbeprovidedwithenhanced levelsofsecurity.

Westpower is currently investigating the use of probabilistic planning techniques to assist in the evaluationofsecurityandreliabilitybenefitsforspecifiedprojects.Thesetechniquesareapplicabletonetworkplanningprocesses,aspowersystembehaviourisstochasticinnature.Ajustificationfortheuseofthisapproachisthatitinstilsmoreobjectiveassessmentsintothedecision-makingprocess.

Inparticular,probabilistictechniquescanbeusedtoprovidemeasurableperformanceindicessuchas:

• Systemavailability,

• Estimatedunsuppliedenergy,

• Numberandsizeofloadcurtailments,

• Numberofhoursofinterruption,

• Excursionsbeyondsetvoltagelimits.

Whiletheuseofaprobabilisticplanningapproachofferssignificantbenefits intermsoftargetedCAPEX,theproperapplicationofthistechniquealsoinvolvessignificantinvestment,bothintermsofcostandresources.Inparticular,thefollowingprerequisitesapply:

• Competent staff, including experienced reliability engineers who are familiar with the application ofprobabilistictechniquestopowersystems;

• Accurateandcompletehistoricalfaultoutagerecordsoveralargenumberofyears;

• Expensiveandcomplexreliabilityevaluationsoftwarepackages,user-friendlyversionsofwhichhaveonlybecomegenerallyavailableinthelasttwoyears.

Accordingly,probabilisticplanningtechniquesarenotwidelyused,exceptsofarastheseareappliedfornetworkdevelopmentprioritisationasdiscussedinSection5.3.

5.2.3 RegulatoryFactorsandQualityofSupply

Programmesandprojectsaretypicallyjustifiedonthebasisofthefollowingbenefitsfromimprovedvoltagelevelorcontrols:

• Theabilitytomeetanyregulatoryrequirementswithrespecttovoltagestandards;

• Specificcustomerrequirementswhichthecustomeriswillingtopayfor;

• Savingsinlosses;

• ImprovementsintransmissioncircuitcapacityandtheconsequentialdefermentofCAPEX.

Table 5.3 - Minimum Security Levels for Distribution Networks

Circuit Type Maximum Demand Under Normal Conditions Minimum Circuit Arrangement

Overhead Upto1MVA Single-circuit

Underground Upto300kVAUpto1MVAforasinglecustomer Single-circuit

Overhead Greaterthan1MVAanduptotwo-thirdsoffeedercapac-ity Feederbackstopping


Powerqualityisconsideredtobethestandardofthepowersuppliedinanenergisedsystem.Itincludesvoltageregulation,thelevelofharmonicdistortion,andthefrequencyandmagnitudeofpowersagsandsurges.Sagsandsurgesaremomentaryvoltagedipsorincreaseswithdurationoflessthanasecond,generallyfromafewmillisecondstohalfasecond.Powerinterruptionsofmorethanasecondareconsideredtobeoutages,afactorofpowerreliability.

5.2.3.1 VoltageRegulation

WherecustomersarefedfromaLVdistributionsystemthatsuppliesmorethanonecustomer,thedistributionsystemwillnormallybedesignedsothatthephasetoearthvoltageatthecustomer’spointofsupplyismaintainedwithinthelimitsassetoutintheElectricityRegulations(theElectricityRegulations1997allLVvariationsof±6%,exceptformomentaryfluctuationsofthenominalvoltage).Thecustomer’spointofsupplywillusuallybetakenasthecustomer’sservicefuseorpropertyboundary.

Inspecialsituations,orwherethecustomerissuppliedatavoltageotherthanthestandardLV,thedistributionsystemshouldbedesignedsothatthedeliveredvoltageismaintainedwithinthelimitsagreedbythecustomerandWestpower.Wherenosuchlimitsarespecificallyagreedon,thelimitsasstatedintheElectricityRegulationsshallbeapplied(theElectricityRegulations1997allowforvoltagevariationsof±5%oftheagreedvoltageforinstallationssuppliedatotherthanstandardLV).

5.2.3.2 VoltageDropAllowances

Regulated11kVbusbarsonWestpower’sdistributionnetworkareregulatedtoavoltageof102%ofnominalvoltage. The voltage drop across the network should accordingly be distributed as follows undermaximumdesignloadconditions:

• 11kVsystem 2%

• LVsystem 4%

• Servicemain 2%

Inruralareas, theallocationofvoltagedropsmustbedeterminedonacase-by-casebasis.Theactual11kVvoltagedropwill dependon thedistanceof the customer from the regulatedbusbar, and this voltagedropcouldexceed2%.Avoltagedropoflessthan4%ontheLVsystemisthusrequired.Ingeneral,thedesignshouldendeavourtoplacethe11kVsupplypointtotheLVnetworkasclosetothecustomeraspossible,resultingthusinrelativelyshortLVnetworks.

5.2.3.3 Harmonics

Harmonic voltages and currents are generally generated by customer’s equipment. The limits of harmonicvoltageorcurrentpermittedatthepointofconnectionbetweenthenetworkandthecustomer’sinstallation,orthepointofcommoncouplingwithanyothercustomers,areasspecifiedintheNewZealandElectricalCodeofPracticeforHarmonicLevels,NZECP36:1993.Ingeneral,thisrestrictsharmonicvoltagesatlessthan66kVto4%foranyodd-numberedharmonic,2%foranyevenharmonicand5%fortotalharmonicdistortion.

5.2.3.4 RatingofNetworkEquipment

Allequipmenttobeinstalledonthenetworkshallbeadequatelyratedbothintermsofloadcapacityandintermsof fault levelwithstandingcapability. Inassessing thecurrentor load rating,dueallowanceshouldbemadeforfutureloadgrowth.Whereappropriate,allowancemaybemadeforthecyclicalnatureofanyload.

In terms of fault ratings, before selecting the fault level withstanding rating of a network component, theactualfaultlevelatthelocationonthenetworkatwhichthenetworkcomponentistobeinstalledshouldbedetermined.Anyexpectednetworkreconfigurationshouldalsobetakenintoaccount.

AfterDiversityMaximumDemand(ADMD)isthemostcriticalvariablefactorinLVsystemdesign,asitsaccurateselectiondirectlyaffectstheoptimumcostsofaninstallationandqualityofsupply.


ItisthereforeimportantthatemphasisisappliedtotheoptimumselectionofADMD.Accordingly,ADMDhasbeenrevisedanddependsmainlyonthedevelopmenttypeaspresentedbelow.

5.2.3.5 CommercialAreas

Innewcommercialdevelopments,wheresmallfactories,retailshopsorsimilarrequireLVdistribution,noADMDcanbepredicted,asitisnotknownwhatoperationswilloccupythepremises.Loadestimatesshouldbegenerous,becausethecostoflaterLVcablereinforcementcanbeconsiderable.Transformerloadestimatesmaybemoreconservative.ThedesignershoulddiscusseachcasewithdevelopersandWestpowerbeforeproceeding.

5.2.3.6 UrbanResidentialAreas

ThenetworkshallbedesignedforanormalresidentialADMDof5kWperdwelling.Inspecialareas,identifiedbyWestpower,thismaybeinsufficientandthedesignADMDshallbeasspecifiedbyWestpower.Inareaswherezoning allowsmultiple residential dwellings and theproperty areapermits, an allowancemustbemade formultipledwellingsperlot.

5.2.3.7 RuralAreas

CaremustbetakentodeterminetheADMDperconsumerinruralareas.Appropriateallowancemustbemadeiflargeirrigationpumpsaretobeconnectedorifsignificantelectricalheatingistobeinstalledinlargeresidentialbuildings.

Thedesignandselectionoftheequipmentusedfortheconstructionofoverheadlinesmustmeet,atleast,thefollowingrequirements:

• Safety-Thelinemustbesafeforlineworkerstoconstructandmaintain,andmustoffernohazardtothegeneralpublic.

• Electricalperformance-Thelinemustadequatelyservethepurposeforwhichithasbeendesigned.Itmustsafelycarryanyloadcurrentwhichitmaybecalledupontodowithoutcreatingproblemsofunacceptablevoltagedrop.Itmustalsobeabletowithstandanyfaultcurrentthatitmaycarryfromtimetotime.

• Mechanicalperformance-Thelinemustbeabletowithstandreasonablenaturalforcessuchaswind,rain,snowandearthquakes.

• Financialperformance-Thelineshouldbedesignedtobeaseconomicalaspossible,takingintoaccounttheoriginalcostofmaintenanceandcostoflinelosses.

• Appearance-Considerationmustbegiventotheimpactofthelineontheenvironmentinchoosingthelinerouteandtheaestheticappearanceoftheline.

5.3 Prioritising Network Development

Westpowerstrivestoensurethatoptimalcapitalefficiencyisgainedthroughtheapplicationofaformalprojectevaluationprocess forcapitalprojects,as thesemustcompete for scarcecapital resources. In thisway,onlyprojectsthatmeetWestpower’sstrictcriteriawillgoforwardandprojectswillalsobecompletedinthebestmeritorder.

As thekeydrivers fornetworkdevelopmentcomprisebothfinancialandnon-financial factors, the followingcategorieshavebeendeterminedsothattailoredplanningcriteriacanbeappliedwhilestillprovidingobjectiveoutcomes:

• CategoryA–projectswithnodirectfinancialjustification;

• CategoryB–projectswithmarginalfinancialbenefits;

• CategoryC–projectswithclearfinancialreturns.

ForCategoryAprojects, thereareanumberofdiversedrivers thatneedtobecarefullyevaluatedandthencomparedonanobjectiveandequivalentbasis.Theseareenumeratedbelow.


1. Reliability/securityofsupplytomeetcustomerlevelsofserviceandcontractualobligations;

2. Asset replacement and renewal requirements to maintain the service delivery potential of the asset,andavoidunnecessaryandunscheduledreactivemaintenance;

3. Occupational health and safety to establish a safe environment both for workers and the public, andcomplywithOccupationalHealthandSafety(OSH)legislativesafetyrequirements;

4. Regulatorycompliancetomeetregulationsimposedbyexternalgovernmentalagencies;

5. Environmentaltocomplywithemissionregulationstoair,landandwater;

6. Quality of supply to ensure that all consumers receive a quality of supply that meets Westpower’sminimumperformancestandards;

7. Technologicalefficiencytoensurethatappropriatecurrentbusinesstechnologyisappliedinthebusinesstoleverageoverallperformancegains;

8. CorporateimagetoensurethatanyactivitycarriedoutbytheassetmanagementteamandsubcontractorswillnotmateriallydamageWestpower’simage.

Anobjectivescoringsystemhasbeendevelopedtoprovideanequitablecomparisonbetweenprojectswithinthis category,even though theymighthavequite separatedrivers. For instance, in thecaseofDriver1, theassessedimpactonboththeSAIDIandSAIFIreliabilitystatisticsisdeterminedeitherbyempiricalorprobabilisticmeans,andtheweightedscoreforeachmetriciscombinedtogiveanoverallscore.Ontheotherhand,ifDriver7werethekeydriver,amultivariateapproachusingfactorssuchasproductivityeffects,equipmentcostsandlikelyusagewouldbeappliedtocomeupwithacomparablescore.

CategoryBprojectsarebasedonclearfinancialcriteriathatcanbeassessedusingfinancialevaluationtools.Thefollowingsub-categoriesareincluded:

1. Efficiency improvements resulting in a reduction in losses or costswhilemaintaining asset performancecriteria;

2. Demandsidemanagement,reducingWestpower’soverallpeakdemandcharges;

3. Renewalandreplacementwhereaclearbusinesscasecanbeprovidedforreplacementofanassetthroughreducedmaintenancecosts;

4. Capacity enhancement where additional capacity is required by a consumer and this can be fundedthroughincreasedlinecharges;

5. Strategic,leadingtolong-termquantifiablestrategicbenefitsforthecompany.

Westpower has developed a robust evaluation tool using industry best practice CAPEX software to provideobjectivityanddisciplinearoundthisprocess.Thisunderlyingapproach isbaseduponDiscountedCashFlow(DCF)analysisbuttheproducthasbeenadaptedforWestpower’sneedsbyaddingexpertdecisionsupporttools.

CategoryCprojectsaresimilartothoseincludedinCategoryB,butbecauseofthedifferentriskprofilesinvolved,theyhavedifferenthurdleratesandsuccesscriteriaappliedtothem.Theseprojectscouldinclude:

1. Networkextensions,includingnewsubstations;

2. Subdivisionreticulation;

3. Communication infrastructure, where there is an ability to share costs with third-party users of thenetwork;

4. Distributedgeneration,suchasthenewAmethysthydroschemethatWestpoweriscurrentlyassessingthefeasibilityof.

Asdiscussedabove,thesameevaluationtoolsareusedforbothCategoryBandCategoryCprojects.


Eachoftheseabovecategoriesisevaluatedbyusingaweightedscoringsystemthatisbasedontheavailablemetrics.

Appropriateweighting factorsare thenapplied toensure thatprojects canbe comparedacrosseachof thecategoriestodevelopastackofprojectsthatcanbeprogressedinapredeterminedmeritorder.Thismethodthereforeprovidesafaircomparisonbetweenfinancialandnon-financiallydrivenprojects,andthisobviatestheneedtoapplyseparateenvelopetoolsforthenon-financiallydrivenprojects.

Whetherornotaprojectwillproceedinanygivenyearwilldependuponwhetherthescoreforthatprojectreaches the project inclusion threshold for that year. In turn, the thresholdwill be determined by financialperformancerequirementsandbudgetaryconstraints,andthesemayvaryfromyeartoyearduetoanumberofexternalbusinessdrivers.Ifaprojectfailstomeetthethresholdinthecurrentyear,itwillbemovedintothefollowingyearforreassessmentalongwithothercompetingprojects.

Thisprocessmakes sure thatonlyprojects thatmeetWestpower’s strict criteriaproceed, and thatnetworkinvestmentiscarriedoutefficientlyandintherightordertoensureoptimumuseofscarcecapitalresources.

Inadditiontothespecificratingsystemusedforkeyprojectsnotedabove,anumberofgeneralprinciplesareappliedwhendecidingtheorderinwhichprojectsshouldproceed.Thesegenerallyfallintothecategoriesbelow:

1. Toppriority isgiventomeetingthe loadrequirements fornew, large (mainlymining) industrial loads.Astherearenonewmajorloadsthathavecommittedatthisstage,noassociatedprojectsareincludedinthisAMP.

2. Secondpriorityisgiventosubtransmissionaugmentationrequiredtomeetcapacitylimitationsasaresultofincrementalloadgrowth.TheonlyseriesofprojectsthatfallunderthiscategoryaretheSouthWestlandGridReinforcement(SWGR)projects.TheseinvolveupgradingtheexistingHokitikatoHarihari33kVlineto66kVoperation,alongwiththeassociatedsubstationsatRoss,WaitahaandHarihari.Currently,projectedfor2019,theactualdatewilldependonmajorgenerationdevelopmentinSouthWestlandsuchasthepotentialWaitahahydroschemenotedinSection3.13.

3. Thirdpriority is given to subtransmission asset replacement, anddistributionnetworkdevelopment andreplacement.ThereplacementandrenewaloftheHokitikatoHarihari33kVlineisthemajorprojectinthiscategory.

5.4 Load Forecasting

5.4.1 Introduction

Acritical factor in consideringnetworkdevelopmentplans is theprojected loadgrowth.Theprojected loadgrowthispresentedinFigure5.4andrepresentsafterdiversitydemand, includingtheloadsuppliedthroughlocalgeneration.

Themethodologyusedtodeterminetheloadgrowthtakesonlyafterdiversitydemandintoconsideration.

Itisanticipatedthatthecurrentmaximumdemandofaround50MWwillrisetoabout65MWintenyears.

Typicalcustomerrequestsrelatetoissuesofcapacity,qualityand/orsecurityofsupply,andcanleadtoplansforassetenhancementordevelopment.TheseareoutlinedinSection4,withparticularreferencetoTable4.12and4.13.

Themostcommonupgradeinrelationtocapacityistheinstallationofnewortransferredsupplytransformersatconnectedpoints,thusprovidingsufficientcapacitytoallowforfuturedemandgrowth.Resolutionofsupplyquality issues typically includes provision of local voltage support in the formof regulators or capacitors tomaintainthesteady-statevoltagewithinspecifiedranges.


Alternatively,networkanalysisincludingloadprojectionsatpointsofsupply,powerflows,networkandpointofsupplyperformanceleadstooptionsforconsiderationbycustomersandWestpowermanagement.Table5.5showsatypicalexampleofaloadtrendtable.

5.4.1.1 HistoricalFactors

Futureloadprojectionisadifficulttaskandisbasedonacomplexmultivariateenvironment.

Someofthefactorsthataffectfutureloadinclude:

• Climaticconditions,

• Economicactivity,

• Commodityprices,

• Foreignexchangerates,

• Majorsteploadincreases/decreases.

Arelativelywarmwinterhasasignificantimpactonwinterheatingloadsandasaresulthasamajoreffectontheannualpeakload.

Overall economic activityon theWestCoast,which is closely linked toworld commodityprices forprimaryproductssuchascoal,goldanddairyproducts,hasadirectfilterdowneffectonelectricityconsumption,andthisoftenhasmediumtolong-termeffectswhennewinvestmentdecisionsaretriggered.

Withtherelativelysmalloveralldemandof50MW,majorstep loadchangeshaveagreat impactonsystemdemand.Unfortunately,thesearealsothemostdifficulttopredictorquantify,astheydependoninvestmentdecisionsfrommajorindustries.Historically,finalcommitmentsontheseprojectshavebeendeferredtoaverylatestage,ofteninvolvingsignificantlast-minuteloadrevisions,leavingWestpowerinadifficultsituationfromaplanningperspective.

Figure5.4-LoadTrends

http://moss/asset/doc/amp/data/2012 AMP Data 26/01/2012

0

10

20

30

40

50

60

70

2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021

MW

Calendar Year

Load Trend(Actual/Forecast)

Dobson Greymouth Kumara Hokitika Reefton Otira Atarau

ADMD (50.5 MW)


Table5.5-Loa

dTren

dsand

Forecaststo

202

1

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

2021

Reeft

on

-

----

----

-

---

----

---

---

----

---

---

----

---

100.0

0%

1.5

5%

-1.8

3%

17.4

9%

-0.9

0%

1.0

0%

0.9

9%

1.0

7%

1.0

6%

0.9

6%

0.9

5%

0.9

4%

0.9

3%

0.9

2%

0.9

2%

Ata

rau

-

----

----

-

---

----

---

---

----

---

---

----

---

---

----

---

100.0

0%

239.4

5%

75.9

5%

-89.1

2%

0.5

0%

0.5

0%

134.3

9%

57.3

4%

36.4

7%

0.1

0%

0.1

0%

0.1

0%

0.1

0%

0.1

0%

Dobson

6.0

8%

16.0

4%

10.5

1%

-17.0

9%

-30.1

7%

33.9

2%

41.1

4%

-14.6

5%

0.3

1%

1.1

8%

1.0

3%

11.6

7%

-0.0

3%

3.5

2%

5.8

6%

9.1

8%

7.5

7%

0.5

7%

0.5

7%

Gre

ym

outh

-3

8.3

6%

12.3

8%

-8.8

5%

-4.9

3%

3.7

1%

-7.1

7%

21.9

0%

-4.0

7%

8.6

4%

3.2

5%

1.9

8%

1.9

4%

1.9

0%

1.8

3%

1.8

0%

1.7

6%

1.7

3%

1.7

0%

1.6

8%

Kum

ara

10.1

5%

-21.1

0%

17.3

7%

15.3

9%

16.9

7%

-15.0

4%

-23.3

0%

-0.1

5%

16.7

8%

0.0

3%

0.0

3%

0.0

5%

0.0

0%

0.0

0%

0.0

0%

0.0

0%

0.0

0%

0.0

0%

0.0

0%

Hokitik

a19.1

3%

-9.9

7%

12.6

8%

14.5

4%

1.0

9%

4.8

1%

-9.8

1%

5.7

0%

-5.2

2%

2.9

3%

-13.8

5%

3.2

2%

2.4

3%

3.0

7%

2.0

7%

2.0

3%

1.9

9%

3.2

2%

1.8

9%

Otira

-63.2

2%

5.4

7%

-71.8

5%

531.5

8%

-37.9

2%

69.8

0%

-90.1

2%

44.0

0%

341.6

7%

1.0

0%

0.9

9%

0.9

8%

0.9

7%

0.9

6%

0.9

5%

0.9

4%

108.6

7%

26.2

6%

0.3

5%

To

tal

Lo

ad

-6.5

5%

3.1

9%

5.7

0%

7.1

5%

3.8

1%

8.2

0%

12.5

9%

3.5

9%

-8.4

0%

2.0

8%

-3.4

7%

6.4

2%

2.8

2%

3.9

0%

2.7

3%

3.7

1%

3.9

3%

1.7

8%

1.1

4%

Actu

al

Actu

al

Actu

al

Actu

al

Actu

al

Actu

al

Actu

al

Actu

al

Actu

al

Fo

recast

Fo

recast

Fo

recast

Fo

recast

Fo

recast

Fo

recast

Fo

recast

Fo

recast

Fo

recast

Fo

recast

kW

kW

kW

kW

kW

kW

kW

kW

kW

kW

kW

kW

kW

kW

kW

kW

kW

kW

kW

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

2021

Reeft

on

00

02986

7216

7328

7194

8452

8376

8460

8544

8635

8726

8810

8894

8978

9061

9145

9229

Ata

rau

00

00

336

948

3218

5662

616

619

622

1458

2294

3131

3134

3137

3140

3143

3147

Dobson

11155

12944

14305

11860

8282

11091

15654

13361

13402

13561

13701

15300

15295

15833

16761

18300

19686

19798

19909

Gre

ym

outh

8866

9964

9082

8634

8954

8312

10132

9720

10560

10903

11119

11335

11551

11762

11973

12184

12396

12607

12818

Kum

ara

1649

1301

1527

1762

2061

1751

1343

1341

1566

1566

1567

1568

1568

1568

1568

1568

1568

1568

1568

Hokitik

a

14098

12693

14302

16381

16560

17357

15655

16548

15685

16144

13908

14355

14705

15156

15470

15783

16097

16615

16929

Otira

256

270

76

480

298

506

50

72

318

321

324

328

331

334

337

340

710

896

900

To

tal

Lo

ad

36024

37172

39292

42103

43707

47293

53246

55156

50523

51574

49784

52978

54470

56594

58137

60291

62658

63772

64499

PE

RC

EN

T I

NC

RE

AS

E O

R D

EC

RE

AS

E


Reefton Delivered

-

1.00

2.00

3.00

4.00

5.00

6.00

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Month

GW

h

0.0

2.0

4.0

6.0

8.0

10.0

12.0

MD

(M

W)

GWh MD

Dobson 33 Delivered

-

1.00

2.00

3.00

4.00

5.00

6.00

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Month

GW

h

0.0

5.0

10.0

15.0

MD

(M

W)

GWh MD

Greymouth Delivered

-

2.00

4.00

6.00

8.00

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Month

GW

h

0.0

5.0

10.0

15.0

MD

(M

W)

GWh MD

Kumara Delivered

-

0.10

0.20

0.30

0.40

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Month

GW

h

0.0

0.5

1.0

1.5

2.0

MD

(M

W)

GWh MD

Hokitika Delivered

-

2.00

4.00

6.00

8.00

10.00

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Month

GW

h

0.0

5.0

10.0

15.0

20.0

MD

(M

W)

GWh MD

Otira Delivered

-

0.05

0.10

0.15

0.20

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Month

GW

h

0.0

0.2

0.4

0.6

0.8

MD

(M

W)

GWh MD

Total Load ex Transpower

-

5.00

10.00

15.00

20.00

25.00

30.00

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Month

GW

h

0.0

10.0

20.0

30.0

40.0

50.0

60.0

MD

(M

W)

GWh MD

Atarau Delivered

-

0.50

1.00

1.50

2.00

2.50

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Month

GW

h

0.0

2.0

4.0

6.0

8.0

MD

(M

W)

GWh MD

Figure5.6-GXPEnergyandDemandStatistics-2011


Acarefulandrigorousapproachhasbeentakentodevelopingfutureloadprojectionsbasedonhistoricaltrends,available informationandestimateson futurechanges.Theseprojectionsdonot takeanyof theembeddedgenerationonWestpower’snetworkintoaccountbecausethetotalenergydeliveredisnotaffectedbythem.

Firstly,loadtrendsateachGXPovertheprevioussevenyearsarestudiedtotryandidentifyhistoricbaselinechanges.Theeffectsofknownsteploadincreasesareextracted,leavingtheunderlyinglong-termhistoricloadprofile.

Figure5.6(previouspage)showstheGXPdemandforthe2011calendaryear.

Basedonthesedata,andgeneralknowledgeofthelocaleconomyandotherdriversdiscussedabove,anestimateismadeofthelikelyfuturetrendinloadgrowthonaGXPbasis.Thisthenprovidesanewbaselineforfurtherwork.

5.4.2 FutureGXPLoadProjections

Customerinputissoughtthroughforumswheremajorpotentialusersaregatheredandprovidedwithupdatesoncurrentloadtrendsandcapacityprojections.Followingthis,eachcustomerorcustomergroup(e.g.tourism)isaskedtoproviderealisticforwardloadprojectionsbasedontheirspecificindustryknowledge.Thisinformationhasprovedtobeextremelyvaluable,andthedatacollectedforthecurrentplanningexercisehaveresultedinasignificantlyimprovedprojectionforfutureloads.ThishasadirectimpactonWestpower’sfutureplansfornetworkreinforcement.

Thedatacollectedfromthecustomersareanalysedandadjustedwithaweightcoefficientbasedonthelikelihoodofoccurrence,andtheresultsareincludedintothezonesubstationloadforecasts.ThisistermedaLoadwatch.Thelikelihoodweightcoefficientsare:

• Loadisconfirmed=100%;

• Loadislikelytooccur=70%;

• Loadispossibletooccur=30%;

• Loadisspeculative=10%.

Table5.7belowshowsthecurrentmaximumdemand,firmcapacityandutilisationfactor.

This table showsnon-coincident demands at eachGXPand includes periodswhere loadhas been switchedbetweenGXPs.Nevertheless,itreflectstheloadthateachGXPmustbecapableofsupplying.

Although the local economyhasbeen significantly impactedby thePikeRiverminedisaster, theunderlyingeconomic growth on the West Coast from other sectors such as the dairy, gold and timber industries isunderpinning solid performance.Over the next two years, this underlying effect is expected to continue asworldwidedemandforcommoditiescontinuestorecover.

Currently,therearenomoreconstraintsinthetransmissionnetworkfeedingtheWestCoast,meaningthatmuchoftheloadcouldbeconsideredasuninterruptible,asthereissufficientn-1transmissioncapacityavailable.

Table 5.7 - GXP Maximum Demand and Current Capacity Utilisation

GXP Feeder Maximum Demand 2011 (MW)

Maximum Demand 2011 (MVA)**

Firm Capacity (MVA) Utilisation %

DOB0331 13.793 14.519 17 85.41%

GYM0661 13.444 14.152 15 94.34%

KUM0661 9.540 10.042 10 100.42%

HKK0661 18.452 19.423 20 97.12%

OTI0111 0.694 0.731 2.5 29.22%

RFN110 9.916 10.438 30 34.79%

ATU110(LGN110)* 1.104 1.162 20 5.81%

*TheAtarauswitchingstationsuppliesLogburnsubstationandthereforetheutilisedfactorisapplicabletoLogburn.

**Themaximumdemand(MVA)iscalculatedbasedontheassumptionthatthepowerfactoris0.95.


Withsuchastrongcommunitysupport,theWCGUPwascompletedsuccessfullylate2011.Theoverallprojecthadthefollowingscopeofwork:

• Installasecond110kVcircuitbetweenReeftonandDobson;

• Installasecond110/66kVtransformerattheDobsonsubstation;

• Installanew14MvarfastswitchingcapacitorbankattheHokitikasubstation.

TheHokitikacapacitorsectionoftheprojectwascompletedinJune2010,andthe110kVlineandassociatedtransformerwascompletedinlate2011.

Thereasonfortheinstallationofthenew14MvarswitchingcapacitorbankatHokitikaistoprovidefastswitchingreactivesupporttohelppreventvoltagecollapseintheWestCoastareafollowinganemergency.

Thegreatestchallenge inplanning for futurenetworkdevelopment is toaccuratelydeterminethe likelihoodandsizeoffuturestepchanges.Toa largeextentthis isbasedondiscussionswithexistingorpotential largeconsumers.Earlyloadindicationsprovidedbytheseconsumersareoftenveryapproximateandaresubjecttomajorvariationsifandwhentheprojectproceeds.

Furthermore, theWest Coast has a history of prematuremajor development announcements beingmade,onlytofallthroughwhenmacro-environmentalchangesoccursuchasthegoldpricedroppingorachangeingovernmentpolicy.Forthisreason,theprojectedsteploadchangesmustbeviewedcircumspectlyuntilthereisafirmcommitment.

Twoofthelargerindustrialcustomershaveindicatedtheywillbeincreasingtheirloadoverthenextfiveyearsaspresentedbelow:

1. WestlandMilkProductsisplanningtoinstallafurtherdryerin2014andthiscouldaddanother2-4MWtotheirload.

2. SolidEnergyNewZealandLimitedis investigatinganewcoalminenearStrongman(about4MW),whichcouldhappenby2015.

Additionaltotheabovementionedloads,severalnewdairyfarmsmaybedevelopedintheFoxGlacierareaontheLandcorpFarmingLtdpropertyoverthenextfiveyearsnowthatWestlandMilkProductshasextendeditscollectionareatoincludethisregion.

Theimpactofsmallembeddedordistributedgenerationisnottakenintoaccountintheloadforecast,mainlybecause it isnotguaranteed that thisgenerationwillbeavailablewhen requiredandWestpowerprefers toadoptaprudentpeakdemandforecastapproach.

Theprojectedadditionaldemandoverthenexttenyearsisintheorderof15MW.PriortotheWCGUPbeingcommissioned,theTranspowersupplycapacityfromthenorthwasconstrainedtoabout24MWwhilethetotalafter diversity systemdemand is around 50.5MW. TheDOB-TEEA line effectively doubles the transmissioncapacity,thusprovidingsecuritytotheWestCoastgrid.

5.4.3 FutureZonesubstationLoadProjections

Loadforecastingiscarriedoutatthezonesubstationlevel,andthisiscriticaltoensurethatsufficientcapacityisavailableinWestpower’ssubtransmissionandzonesubstationinfrastructure.Theseforecastsaredevelopedusingazero-basedapproachandloaddemandmanagementfrominformationandrequestsreceiveddirectlyfromcustomers,includingintelligenceonfutureloadtrendssuchasproposeddairyfarmconversions.

FuturezonesubstationloadprojectionsdemonstratethatmostofWestpower’szonesubstationshavesufficientcapacitytodealwithexpected loadgrowththroughouttheplanningperiod,althoughsomesubstationsmayrequire capacity upgrades in eight to ten years. As these load forecasts are subject to change and involveconsiderableuncertainty,noprojectshavebeencommittedforthezonesubstationsatthisstage,butaclosewatchwillbekeptoncustomers’loadexpectationsandmaximumdemandtrends.


InWestpower’scase,mostofthesubtransmissioninfrastructurehasbeenbuiltwithinthelast20yearsandhasbeenprudentlydesignedtocaterforfutureloadgrowth,whichmeansthatthereisusuallyamplecapacitytocaterformarginalloadgrowth.Intheeventofproposalsformajorloadstepscrystallising,eachcaseisconsideredinisolationandincombinationwithotherproposalstomakesurethatanyconstraintsduetosubstationcapacityaretakenintoaccount.

AsummaryoftheresultsbymajorzonesubstationisshowninTable5.8.

Table 5.8 - Zone Substation Forecast Demand

Zone Sub-station

Firm Capacity (MVA)

Peak 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Block Arnold 5 3.357 3.36 3.39 3.42 3.45 3.47 3.48 3.50 3.52 3.52 3.52 3.52

BaseGrowth 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

LoadwatchGrowth 0.03 0.03 0.04 0.02 0.02 0.02 0.02 0.00 0.00 0.00 0.00

PredictedLoad 3.39 3.42 3.45 3.47 3.48 3.50 3.52 3.52 3.52 3.52 3.52

Block Blackwa-ter 5 1.47 1.47 1.50 1.53 1.56 1.79 2.02 2.25 2.28 2.31 2.34 2.37

BaseGrowth 2.0% 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03


PredictedLoad 1.50 1.53 1.56 1.79 2.02 2.25 2.28 2.31 2.34 2.37 2.40

Block Dobson 5 1.875 1.88 1.94 2.01 2.08 2.15 2.21 2.28 2.33 2.39 2.43 2.47

BaseGrowth 2.0% 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04


PredictedLoad 1.94 2.01 2.08 2.15 2.21 2.28 2.33 2.39 2.43 2.47 2.51

Block FoxGla-cier 5 0.750 0.75 0.77 0.78 0.80 0.81 0.83 0.84 0.86 0.87 0.89 0.90

BaseGrowth 2.0% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02


PredictedLoad 0.77 0.78 0.80 0.81 0.83 0.84 0.86 0.87 0.89 0.90 0.92

Block FranzJosef 5 1.718 1.72 1.75 1.79 1.82 1.86 1.89 1.92 1.96 1.99 2.03 2.06

BaseGrowth 2.0% 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03


PredictedLoad 1.75 1.79 1.82 1.86 1.89 1.92 1.96 1.99 2.03 2.06 2.10

Block Globe 8 5.616 5.62 5.84 6.07 6.20 6.23 6.26 6.28 6.31 6.34 6.37 6.40



Zone Sub-station

Firm Capacity (MVA)

Peak 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

BaseGrowth 0.5% 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03


PredictedLoad 5.84 6.07 6.20 6.23 6.26 6.28 6.31 6.34 6.37 6.40 6.42

Block Grey-mouth 15 13.444 13.44 13.88 14.16 14.43 14.71 14.97 15.24 15.51 15.78 16.05 16.32

BaseGrowth 2.0% 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27 0.27


PredictedLoad 13.88 14.16 14.43 14.71 14.97 15.24 15.51 15.78 16.05 16.32 16.59

Block Harihari 1 1.044 1.04 1.07 1.10 1.12 1.15 1.17 1.19 1.21 1.23 1.25 1.27

BaseGrowth 2.0% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02


PredictedLoad 1.07 1.10 1.12 1.15 1.17 1.19 1.21 1.23 1.25 1.27 1.29

Block Hokitika 20 18.452 18.45 18.99 16.36 16.89 17.30 17.83 18.20 18.57 18.94 19.55 19.91

BaseGrowth 2.0% 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37 0.37

LoadwatchGrowth 0.17 -3.00 0.16 0.04 0.16 0.00 0.00 0.00 0.24 0.00 0.00

PredictedLoad 18.99 16.36 16.89 17.30 17.83 18.20 18.57 18.94 19.55 19.91 20.28

Block Kumara 10 9.540 9.54 9.54 9.55 9.55 9.55 9.55 9.55 9.55 9.55 9.55 9.55

BaseGrowth 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00


PredictedLoad 9.54 9.55 9.55 9.55 9.55 9.55 9.55 9.55 9.55 9.55 9.55

Block Logburn 20 1.104 1.10 1.11 1.12 2.61 4.11 5.61 5.62 5.62 5.63 5.63 5.64

BaseGrowth 0.5% 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01


PredictedLoad 1.11 1.12 2.61 4.11 5.61 5.62 5.62 5.63 5.63 5.64 5.64

Block Ngahere 5 3.107 3.11 3.17 3.00 3.69 3.26 3.32 3.38 3.44 3.50 3.57 3.63

BaseGrowth 2.0% 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06

LoadwatchGrowth 0.00 -0.23 0.63 -0.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00



Zone Sub-station

Firm Capacity (MVA)

Peak 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

PredictedLoad 3.17 3.00 3.69 3.26 3.32 3.38 3.44 3.50 3.57 3.63 3.69

Block Otira 2.5 0.694 0.69 0.70 0.71 0.71 0.72 0.73 0.74 0.74 1.55 1.96 1.96

BaseGrowth 1.0% 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01


PredictedLoad 0.70 0.71 0.71 0.72 0.73 0.74 0.74 1.55 1.96 1.96 1.97

Block Pike 15 0.761 0.76 0.79 0.81 0.83 0.83 0.83 0.83 0.83 0.83 0.83 0.83

BaseGrowth 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00


PredictedLoad 0.79 0.81 0.83 0.83 0.83 0.83 0.83 0.83 0.83 0.83 0.83

Block Rapahoe 5 2.177 2.18 2.22 2.27 2.32 2.37 2.41 2.46 2.50 2.54 2.59 2.63

BaseGrowth 2.0% 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04 0.04


PredictedLoad 2.22 2.27 2.32 2.37 2.41 2.46 2.50 2.54 2.59 2.63 2.67

Block Reefton 30 9.916 9.92 10.02 10.11 10.22 10.33 10.43 10.53 10.63 10.73 10.83 10.93

BaseGrowth 1.0% 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10 0.10


PredictedLoad 10.02 10.11 10.22 10.33 10.43 10.53 10.63 10.73 10.83 10.93 11.02

Block Ross 1 0.447 0.45 0.46 0.47 0.47 0.48 0.49 0.50 0.51 0.52 0.53 0.54

BaseGrowth 2.0% 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01


PredictedLoad 0.46 0.47 0.47 0.48 0.49 0.50 0.51 0.52 0.53 0.54 0.55

Block SpringCreek 8 6.638 6.64 6.64 6.84 8.04 8.34 8.84 9.84 11.64 13.24 13.24 13.24

BaseGrowth 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00


PredictedLoad 6.64 6.84 8.04 8.34 8.84 9.84 11.64 13.24 13.24 13.24 13.24


5.4.4 PossibleConstraints

5.4.4.1 HarihariSubstation

Themaximumpeakdemandrecordedin2011wasabout1MVAandreachedthefirmcapacityofthesubstation.Toeliminatethisconstraint,thesubstationcapacityneedstobeincreasedoraloadmanagementprogrammeneedstobeimplemented.

TheInternationalElectrotechnicalCommission(IEC)standardsstatethateveryoil-filledtransformermanufacturedinaccordancewiththestandard,hastowithstanda25%loadincreaseoveritsnominalcapacitycontinuously.Therefore,eventhoughthepeakloadhasreachedthefirmcapacityofthesubstation,thetransformershouldwithstandanextra25%ofloadincrease.

Basedontheloadforecast,theloadincreaseby2019is23%abovethefirmcapacityofthesubstation.

Consequently,thetransformerneedstobereplacedwithinthistimeframebyupgradingjustthetransformerintheexistingsubstationiftheloadisincreasingmorethanwhatispredicted.


Zone Sub-station

Firm Capacity (MVA)

Peak 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Block Wahapo 5 3.091 3.09 3.09 3.09 3.09 3.09 3.09 3.09 3.09 3.09 3.09 3.09

BaseGrowth 0.0% 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00


PredictedLoad 3.09 3.09 3.09 3.09 3.09 3.09 3.09 3.09 3.09 3.09 3.09

Block Waitaha 1 0.261 0.26 0.27 0.27 0.28 0.28 0.29 0.29 0.30 0.30 0.31 0.31

BaseGrowth 2.0% 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01


PredictedLoad 0.27 0.27 0.28 0.28 0.29 0.29 0.30 0.30 0.31 0.31 0.32

Block Whataroa 1 0.772 0.77 0.80 0.82 0.84 0.85 0.87 0.89 0.90 0.92 0.93 0.95

BaseGrowth 2.0% 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02


PredictedLoad 0.80 0.82 0.84 0.85 0.87 0.89 0.90 0.92 0.93 0.95 0.96

Legend:

-representsfirmcapacityoverloadedbyupto25%

-representsfirmcapacityoverloadedbyover25%


5.4.4.2 HokitikaSubstation

MaximumpeakdemandrecordedforHokitikasubstationin2011wasabout18.5MVAand,accordingtoourloadforecast,by2019,thetotalloadwillreachthefirmcapacityofthesubstation.AstheHokitikasubstationhastwotransformersinparallel,theconstraintmainlyappliesduringmaintenanceperiodswhenonetransformerwouldbeoutofservice.Thiscouldberesolvedatthemaintenanceplanningstageand/orbyimplementingaloadmanagementprogramme.

5.4.4.3 GreymouthSubstation

Recordingamaximumpeakdemandof13.4MVAlastyearandconsidering2%loadgrowthforthefollowingyears,thedemandforthissubstationcouldreachthefirmcapacityby2017.

Byinstallingoilcirculatingpumpsandfansonbothtransformers,thecapacityhasalreadybeenincreasedfrom10-15MVApertransformer.Therefore,iftheloadreachesfirmcapacitysomemaintenanceconstraintscouldarise.Asmentionedabove,thiscouldberesolvedatthemaintenanceplanningstageand/orbyimplementingaloadmanagementprogramme.

5.4.4.4 SpringCreekSubstation

Eventhoughthepredictedloadwillreachthefirmcapacityofthesubstationby2014,there isnoconstraintidentifiedforthe33kVline.ThesubstationisnotownedbyWestpowerandisincludedinTable5.8onlyforloadforecastpurposes.

5.4.5 ImpactofDemandManagementonLoadForecast

RipplecontrolofwaterheatingformsacorepartofWestpower’sloadmanagementstrategyandprovidestheability todefernetworkexpenditure inareaswhereasset loadingshaveexceededavailablecapacityatpeaktimes.Moreover,oncetheHVDirectCurrent(HVDC)upgradeiscompletedin2012andNewZealandeffectivelybecomesasinglereservesmarket,additionalvaluemaybecomeavailablethroughtheabilitytobidinterruptibleloadintothemarket.

Thereareestimatedtobearound9000waterheaterssuppliedbyWestpower.Approximatelyhalfoftheseareon a fixed night-only ripple control programme that ensures they are not energised during coincident peakperiods.TheafterdiversitydemandoftheremainingwaterheatersintheWestpowernetworkthatareavailableforcontrolbyWestpower’sloadmanagementsystemisestimatedtototal4.5MWatthetimeoftheregionalcoincidentpeakonacoldwinterevening.

Westpower supports injection telegrams for both the older Plessey Rhythmatic receivers as well as newerDecabitunits.However,Westpowerdoesnotownripplecontrolreceiversandthereforehaslimitedabilitytocontroltheirinstallationandmaintenance.

Therippleinjectionsystemismodernandwellmaintained,withsignificantredundancybuiltinthroughtheuseoftime-synchronisedsimultaneousinjectionacrossallfourrippleplantsspreadthroughoutWestpower’sarea.Asaresultofsignificantsignal“spill”,thefailureofasingleplanthasaminimalimpactonoverallsignallevels.

Afterdiversityloadsusedforforecastingloadgrowthinherentlytakeintoaccounttheabilitytoshedloadatpeaktimes,asthesedemandsarebasedonhistoricalloadingfiguresderivedfromactualnetworkperformance.Thisisparticularlytruefornewerhousesusingelectricwaterheating,asgenerouscylindercapacitiesaresupplementedbyadditionalvirtualstoragethroughtheuseoftemperingvalves,leadingtotheabilitytosupplytheloadfullyoff-peakwithanightrateonlytariff.

However, for existing installationswith limited storage, the increasingeffectsofdiversity result in adilutionoftheamountofafterdiversitydemandonthenetworkandloadavailabletoshedatthetimeoflocalpeakdemands,astheloadsareaggregatedacrosszonesubstations,GXPsandentireregions.


Magnifyingthisphenomenon,recentchangestothetransmissionpricingmethodologyhaveledtoWestpowerbecomingapartofajointloadcontrolschemedrivenbyOrionthatfocusesonminimisingtheRegionalCoincidentPeakDemand(RCPD)onTranspower’supperSouthIslandnetwork,ratherthanjustcontrollingWestpower’sownpeakdemandsatlocalGXPs.Thischangeinphilosophyhasresultedinmarkedlydifferentpeakdemandsheddingbehaviour,andtheresultingimpactondiversityandindividualGXPpeakdemandsisstillbeinganalysed.

Oncetheseeffectsareclearlyunderstood,itmaywellresultinWestpowermovingbacktowardsupplementarycontroloflocalGXPdemandinadditiontotheupperSouthIslandcontrolschemeiftherearetangiblebenefitstobehad.Theforecastswouldthenbeupdatedaccordingly.Inthemeantime,theloadforecastsarebaseduponthecurrentdemandmanagementregimeofregionalloadcontrol.

Inanycase,becauseWestpower’snetworkisgenerallyunconstrainedatthedistributionandsubtransmissionlevel, it isunlikelythatevenasignificantchangeindemandmanagementpracticeswouldhaveadiscernibleimpactonshort-to-mediumtermnetworkinvestmentdecisions.

5.5 Distributed Generation

Westpower’spolicy regardingdistributedgeneration is toassistany individualsororganisations through theapplicationprocessandallowtheconnectionofdistributedgenerationtoitsnetwork.

Westpowerwillalsoensurethatanynewdistributedgenerationconnectedtoitsnetworkwillcomplywithallrelevantstatutoryandregulatoryrequirements,andapplicablesafetystandards.

The main framework for implementing this policy is established by Electricity Governance (Connection ofDistributedGeneration)Regulations2007.

Dependingonthemaximumcapacityofthedistributedgenerationtobeinstalled,theapplicationprocessdifferssignificantly.Therefore,for10kWorlessofcapacity,theapplicationwillbeaone-stageprocess;forover10kWofcapacity,itwillbeatwo-stageprocess.

Figure5.9showsthedistributedgenerationprocess.

I. System Selection

Usually,distributedgenerationabove10kWconsistsofdiesel,windorhydrogenerators; thatbelow10kWconsistsoflargearraysofsolarpanelsorrotatingplantssuchaswindturbines.

Theselectionof theequipmentusedaspartof thedistributedgenerationsystemshouldbeplannedaheadtoensurethattheentiresystemcomplieswiththerequirementsoftheHealthandSafetyinEmploymentAct1992,theElectricityAct1992,andtherulesandregulationsmadeundertheElectricityAct1992.ItalsoshallbeinstalledinaccordancewithWestpower’sConnectionandOperationStandardsandAS4777,NZECP4:1993and/orNZS/AS3000:2000-ElectricalInstallations(knownastheAustralian/NewZealandWiringRules)oranysubsequentrevision.

II. Submission of Application

Anypersonororganisationwhowishestoconnectdistributedgenerationcapableofgeneratingelectricityat10kWorlesstothenetworkmustsubmitanapplicationtoWestpowerandprovidealltheinformationrequiredinrespectofthedistributedgenerationproposedtobeconnected.

Theapplicationformhastobeaccompaniedbythefollowingattachments:

1. Informationaboutthenameplateratingorothersuitableevidencethatthegeneratingunitis(orwillbe)onlycapableofgeneratingelectricityatarateof10kWorless;

2. Detailedinformationabouttheinverterand/orbattery(ifapplicable);

3. Technicalspecificationsoftheequipmentthatallowthedistributedgenerationtobedisconnectedfromthenetworkonlossofmainsvoltage;


I

II

III

IV

V

VI

VII

VIII

IX

X

XI

XII

Distributed Generation

Process

10 kW

Capacity or

Less

YES NO

Initial Application

Final Application

Submission of Initial

Application

Initial Application

Evaluation Process

Initial Application

Completed

Submission of Final

Application

Final Application

Approval Process

Notice of Intention to

Proceed

Connection Contract

Negotiation

Installation, Inspection

and Testing

Connection

Established

Application Approval

Process

Submission of

Application

System Selection

Application Process

Connection Process

Figure5.9-DistributedGenerationProcess


4. Information and justification showing how the distributed generation complies with AS4777 (whereappropriate);

5. InformationandjustificationshowinghowthedistributedgenerationcomplieswithWestpower’sconnectionandoperationstandards;

6. Theapplicationfee.

III. Application Approval process

Basedontheinformationprovidedintheapplication,Westpowerwillassessif:

1. TheapplicantcomplieswiththerequirementsoftheHealthandSafetyinEmploymentAct1992;and

2. The distributed generation complies with the Electricity Act 1992, and the regulations and rulesmadeunderthisAct;and

3. The connection of the distributed generation complies with Westpower’s Connection and Operationstandards(Westpower’sDistributionCode).

IV. Submission of Initial Application

Similartothe“SubmissionofApplication”stagefordistributedgenerationwithacapacitylessthan10kW,theapplicantshavetosubmitaninitialapplicationformaccompaniedbydetailedinformationasrequestedintheformandtheapplicationfee.

V. Initial Application Evaluation Process

Afterreceivingacompleteapplicationforadistributedgenerationwithacapacitygreaterthan10kW,Westpowerwillprovidetheapplicantwiththefollowinginformation:

1. Thecapacityofournetwork,includingboththedesigncapacity(includingfaultlevels)andactualoperatinglevels;

2. Theextenttowhichconnectionandoperationofthedistributedgenerationmayresultinabreachoftherelevantstandardsforsafety,voltage,powerqualityandreliabilityofsupplytootherconnectedparties;

3. Anymeasuresorconditions,includingmodificationstothedesignandoperationofWestpower’snetworkortotheoperationofthedistributedgeneration;

4. Theapproximatecostsofanynetwork-relatedmeasuresorconditionsidentifiedabove,andanestimateoftimeconstraintsorrestrictionsthatmaydelaytheconnectionofthedistributedgeneration;

5. Any furtherdetailed investigativestudies thatWestpowerreasonablyconsidersnecessary to identifyanypotentialadverseeffectsonthesystemresultingfromtheproposedconnection;

6. Anyobligationstootherpartiesthatcouldaffectthedistributedgeneration;

7. AnyadditionalinformationordocumentsthatWestpowerconsiderslikelytoassisttheapplication;

8. Informationabout theextent towhichplannedandunplannedoutagesmayaffect theoperationof thedistributedgeneration.

VI. Initial Application Completed

Westpowerwillprovide,ifrequestedbytheapplicant,furtherinformationthatisreasonablynecessarytoenabletheapplicanttoconsiderandactontheinformationprovidedduringtheinitialapplicationprocess.

VII. Submission of Final Application

The final application has to be submitted toWestpower within 12months after the initial application wascompletedandhastobeaccompaniedbyanyinvestigativestudiesthatwereidentifiedduringthatstage.


VIII. Final Application Approval Process

Similartothe“ApplicationApprovalProcess”stagefordistributedgenerationwithacapacitylessthan10kW,basedontheinformationprovidedintheapplication,Westpowerwillassessif:

• TheapplicantcomplieswiththerequirementsoftheHealthandSafetyinEmploymentAct1992;

• ThedistributedgenerationcomplieswiththeElectricityAct1992,andtheregulationsandrulesmadeunderthisAct;

• The connection of the distributed generation complies with Westpower’s Connection and Operationstandards(Westpower’sDistributionCode).

IX. Notice of Intention to Proceed

Oncethefinalapplicationforconnectionofthedistributedgenerationisapproved,theapplicantmustsendawrittennoticetoWestpowerconfirminghis/herintentiontoproceedwiththeconnection.Theapplicantalsohastoacceptalltheconditions(orothermeasures)whichWestpowerhasspecifiedasconditionsoftheconnectionandprovidedetailsofthegenerationtobeconnected.

FailuretoprovideWestpowerwithanoticeofintentionwithinthetimeframespecifiedwillleadtocancellationoftheapplicationandcessationofWestpower’sresponsibilitiesundertheElectricityGovernance(ConnectionofDistributedGeneration)Regulations2007.Thisdoesnotpreventtheapplicantfromsubmittinganewapplicationforconnectionofdistributedgeneration.

X. Connection Contract Negotiation

Afterreceivingthenoticeofintentiontoproceed,boththeapplicantandWestpowershould,ingoodfaith,trytonegotiateaconnectioncontract.

Ifnoconnectioncontractisnegotiatedwithinthepredefinedtimeframe,theregulatedtermsestablishedbytheElectricityGovernance(ConnectionofDistributedGeneration)Regulations2007willapplytothenewconnection.

Theperiodfornegotiatingaconnectioncontractmaybeextendedbymutualagreementbetweenbothparties.

XI. Installation, Inspection and Testing

All wiring associated with the distributed generation system must comply with AS/NZS 3000 - ElectricalInstallations(Australian/NewZealandWiringRules)oranysuccessivestandardorlegislation,andbeundertakenbyaregisteredelectricianwhererequiredbylegislation.

WhileAS4777.1dealsprimarilywiththeconnectionofinverterbasedsystems,theprinciplescoveredbythisStandardshallalsobefollowedfordistributedgenerationsystemsthatdonotemployinverters.Also,theElectricalEngineersAssociation’s(EEA)–“GuidefortheConnectionofGeneratingPlant”mayassisttheapplicantwithdeterminingthemostappropriateelectricalarrangementsfortheconnectionandprotectionofthedistributedgenerator.

BeforeconnectingthedistributedgenerationtoWestpower’snetwork,ithastobeinspectedandtested.Asaminimum,theapplicantmustensurethat:

1. Theinspectionandtestshavebeenarranged;

2. Westpower has received adequate notice regarding the inspection and tests so they can send qualifiedpersonneltothesiteforobservation;

3. Awrittentestreport,includingsuitableevidencethatthemeteringinstallationcomplieswiththemeteringstandardsandrules,isprovidedtoWestpower;

4. ThefeespecifiedbyWestpowerforobservingthetestingandinspectionhasbeenpaid.


XII. Connection Established

Oncetheconnectionhasbeenestablished,theapplicantandWestpowermustperformallobligationsunderthenegotiatedconnectioncontractorregulatedtermsinaccordancewithconnectionandoperationstandards.

5.6 Non-Network Options

Anumberofstrategiesareavailablefordealingwithloadincreases,asshowninTable5.10.

Eachoftheseoptionsiscarefullyevaluatedbasedoneconomicefficiencyandtechnicalperformance.Whereverpossible,capitalintensivedevelopmentisdelayeduntilabsolutelynecessary,andnon-assetintensivesolutionsareusedwherethesearenotincompatiblewithfuturedevelopmentplans.

For instance, reactivesupportand/orvoltageregulation is routinelyemployedtosupportdairy farming loadgrowthinruralareasasthisisfarmorecost-effectivethanoverlayingwithahighervoltage.

Whereveryshorttimeframesareinvolvedandpermanentsolutionsarenotpossiblebeforetheloadcomesonstream,demandsidemanagementisoftenemployedbymakingatleastpartoftheadditionalloadinterruptibleuntilalong-termsolutioncanbeputinplace.

Ignoringsuchincreases,thefirstthreesolutionsidentifiedinthetable,areessentiallynon-assetintensive.

Table 5.10 - Options for Handling Load Increases

Strategy Application

EconomicTariffStructuremodels

Theseoptionsincludedemand-basedtariffs,off-peakdiscountsandpenaltiesforpoorpowerfactor.Bysignallingthetruemarginaleconomiccostsofnetworkextensions,theconsumerisabletorespondtothesepricingsignalsbymodifyingtheirconsumptionbehaviourandreducingtheircosts.Thisisbestappliedinthecaseofmarginalloadgrowthwhereoptimisationofthenetworkisabletounlockitsfull

potential.

DemandSideManagementDemandsidemanagementistypicallyappliedbymeansofripplecontrolswitchingofinterruptible

loadssuchaswaterheatingandnightstoreheaters.Westpowerroutinelyappliesthismethodtoreduceregionalpeakdemand,whichassistsTranspowerinmanagingexistingtransmissionconstraints.

LineDropCompensation

Onlongruralfeederswheremostoftheloadissituatedtowardthemiddleorfarendofthefeeder,linedropcompensationisavalidmeansofimprovingreceivingendvoltageregulationandmaximisingthelinecapacity.Thisisgenerallynotapplicablefor11kVfeederswithdistributedload,asnearendcus-tomerswouldbeadverselyaffectedbyvoltagerise.Cost-effective,butonlyapplicableinlimitedcases.

DistributedGeneration

DistributedgenerationisactivelyencouragedthroughoutWestpower’snetwork,butWestpowerisreliantonothersinvestinginthistechnology.Furthermore,unlessthegenerationisveryreliable,orsufficientlydiverse,thenetworkmuststillbesizedtoprovidefullloadwithoutthebenefitofgenera-tiontocaterfortimeswhenthegenerationisunavailableorbeingmaintained.Distributedgenerationisnotseenasapplicablewhereitistheonlymeanstosupplycontinuousloads,butmaybeusedbya

customerwhoishappytoputupwithoccasionalinterruptionsorconstraints.

VoltageRegulation

Onlong11kVor33kVfeeders,voltageconstraintscanbedealtwithbyinstallingeithercontinu-ouslyvariableorsteppedvoltageregulators.Westpowerappliesthistechnologyinareaswhereeithermarginalorsteploadsincreaseswouldotherwiseresultinunacceptablevoltageprofiles.Theseare

routinelyappliedinWestpower’s33kVor11kVnetworkstocaterforanincreaseindairyfarmloadingintheruralarea.

SystemReconfiguration

Wheresignificantloadsaresituatedattheendofameshedfeeder,itissometimespossibletopro-videenhancedcapacitybyswitchingtheloadtoanearbyfeeder.Inthecaseofonebulkcustomer,aplannedloadincrease(situatednearthetiepointbetweentwofeeders)willbecateredforbyspread-ingthefactoryloadacrosstwofeeders.Thisisverycost-effective,butdependsverymuchonfactors

suchaslocationoftheloadandthereforehaslimitedapplication.

ReactiveCompensation

Thistechniqueinvolvesinstallingcapacitorsonthe11kVdistributionnetworktoboostvoltageandimprovecapacity.WestpowerusesthistechniqueextensivelytosupportruralfeedersandsupportthetransmissiongridvoltagethroughouttheWestCoast.Sinceonlyacertainnumberoffixedcapacitorscanbeinstalledthroughoutthenetworkbeforevoltageriseproblemsoccur,muchmoreexpensive

switchedbanksarethenrequiredandthecost-benefitbalanceisshifted.Switchedcapacitorbanksarealsousedtosupportlargemotorstartingapplications.


Demand-based tariffs give the end user strong incentives to reduce peak demand andmaximise plant loadfactors.ThisresultsinlesspeakdemandandbetterregulationontheWestpowernetwork.

Useofdemandsidemanagementislinkedtothetariffstructure,andallowstheplantorWestpowertocontrolitsinternaldemandbysheddingnonessentialloadatpeakperiods.

LineDropCompensation (LDC) canbeused in specific circumstances toboost the sendingendvoltageonafeedertoimprovedown-lineregulation.Thiseffectivelyincreasestheavailablecapacityonafeeder.

Westpowerhasalsobegunaprogrammeofinstallingcapacitorsatstrategicpointsinthenetworkwherevoltageconstraintsarepresentorimminent.Insomecases,loadgrowthforaparticularinstallationisdependentuponincreasedreactivesupport,andtheconsumerisrequiredtocontributetothecapitalexpenditureinvolved.

Distributed generation is seen as an excellentmeans of reducing demand on the Transpower network andenhancing theperformanceofWestpower’sdistributionnetwork.Assuch,Westpoweractivelysupports thisapproach.Atransparentpricingmethodology is inplacetoensurethat thereare lowentrybarriers fornewgenerators,and,iflargeenough,thatthesenewgeneratorsreceivethefullavoidedcostoftransmissionbenefitsthattheyareentitledto.

Technical requirements for connection of distributed generation are based on the industry standard EEAGuidelines.

Notwithstandingtheabovecomments,thequantumofloadincreasesinthatWestpoweriscurrentlyfacing,asdepictedinTable5.10,meansthatenergyconservation,distributedgenerationorsmallrenewablegenerationprojectsarenot,inthemselves,viablesolutionstotheconstraintsnowbeingfaced.Theydo,however,improvethequalityofsupplyandreducethemarginalcostsandlossesassociatedwithtransmittingenergyintothearea.

TheprocessthatWestpowerusestoidentifyandpursueeconomicallyandpracticalalternativestoconventionalnetworkaugmentationinaddressingnetworkconstraintsistoconsidereachofthefeasiblealternativesdiscussedabove in ascending order of cost and complexity until a solution is found that will meet the requirementsof Westpower and its consumers, without conflicting with Westpower’s medium and long-term planningrequirements.

Forinstance,theRoaMinerecentlysignalledasignificantincreaseindemanddrivenbyincreasedproduction.Themine is fed by a relatively long length of 11 kV line,which involves fewother consumers. In this case,additionalautomaticshuntreactivesupportallowedthedemandtobesuppliedwithoutviolatingacceptablevoltage limitsandalsoavoided theneed to invest inacostly reconductoringexercise.This savedmoney forWestpowerandultimatelytheconsumer,whowasrequiredtoprovideacapitalcontributiontofundthework.

Moreover,Westpowerisopentothedevelopmentofcommercialarrangementsthatcoulddefertheneedfornetworkinvestment(suchasthevoluntarycurtailmentofloadbymajorcustomersattimesofnetworkpeakdemand)andwouldwelcomediscussionwithstakeholdersonthismatter.

5.7 Network Development Options

5.7.1 ReeftonNetwork

Nosignificant loadgrowth iscontained in the loadwatchanalysis for theReeftonarea.Theexistingnetworkshouldbeadequatetohandleongoinggrowth.

In1999,Westpowerextendedits33kVsubtransmissionnetworkintheGreyValleyasfarasReeftonandbuiltanewzonesubstationonTranspower’sReeftonsubstationsite.ThisservedthebasedemandforseveralyearsuntilamajornewloaddevelopedintheformoftheReeftonGoldProject,whichiscurrentlyoperatedbyOceanaGoldLimited.


Developmentofthisproject,involvingaloadof5.2MW,requiredsignificantstrengtheningofthesupplyintotheReeftonarea.Afterconsiderableinvestigation,thesolutionchosenbyWestpowerwastoconstructanew2x20MVA110/33/11kVzonesubstationatReeftonfedbytwo110kVlinesfromInangahua.OneoftheselineswastheexistingTranspowerDOB-IGH66kVcircuit,whichwasupgradedto110kV.Atthesametime,anew110kVspurfromInangahuatoReeftonwasconstructedbyWestpowerandthensoldtoTranspower.

Inaddition,anew33kVlineandsubstationwasconstructedtofeedtheminesiteandthishassufficientsparecapacitytohandleprojectedloadgrowththroughoutthelifeoftheexistingmine.

Alloftheseprojectswerecompletedin2005.

Thisworkwas designed to be compatiblewith Transpower’s own transmission development in the area toensurethatthegreatestsharedbenefitaccruestoconsumersintheareaintermsofbothcapacityandsecurity.ThismeansthattheReeftonareaisnowsuppliedbyastrongtransmissionnetworkwithn-1security,sofurtherdevelopmentwillbelimitedtothedistributionsystem.

Duetovoltageconstraintsonthe11kVcircuitsatIkamatua,anew33/11kVzonesubstationwasrequiredatBlackwatertoprovideanadditional500kWofdemandtothePikeRivercoalload-outfacilityatIkamatua.ThesubstationwascommissionedinDecember2009.

Thenetimpactoftheserecentdevelopmentsisthat,barringanysignificantandunexpectedloadgrowth,nofurtherstrengtheningofthesubtransmissionordistributionnetworkswillberequiredfortheremainderoftheplanningperiod.

5.7.2 GreymouthNetwork

SeveralsignificantcoalminingprojectswillpossiblybedevelopedinthefuturebySolidEnergy’sSpringCreekminenearRapahoe.

Thereisthepossibilityofuptoanadditional14MWbeingrequiredforSolidEnergy’sminesintheRapahoeareaandotherdevelopmentopportunitiesinthesameareawithinthenextfiveyears,butnoneofthisloadhasyetbeencommitted.

DuetothetragiceventthatoccurredatthePikeRivercoalmine,theloadatAtarauGXPhasdecreasedby6MW.Itishardtopredictwhetherthemineisgoingtobere-openedornot,butconsideringthattheinfrastructureisalreadyinplace,theminecouldbereopenedby2013.Ifthisisthecase,theloadcouldreach10-14MWasinitiallypredicted.

Anew110kVGXPswitchingstationatAtarauwascommissionedbyTranspowerin2007asabusontheDOB-RFN-IGHcircuit.Thisswitchingstation,alongwithassociated110kVand33kVlinesandsubstationsconstructedbyWestpower,willprovideforthefullprojectedloadatthissite.

Finally,baseloadgrowthandcontinuingexpansionintheexotictimbermillingandtourismindustrieswillrequirecapacityincreasesinthelongterm,probablyoutsidetheplanninghorizon.

TheexistingWestpower33kVsubtransmissionnetworkcansupportexpectedloadgrowth.TherecentupgradingoftheDOB-RFN-IGHlineto110kVhasalsostrengthenedthesupplyfromInangahuainthenorth,significantlyimprovingfirmcapacityintothearea.

IfTrustpowerproceedswithitsprojecttoupgradeArnoldpowerstation,anew66or110kVsubstationatKokirimaybe required to connect thepower station into the local transmission grid. Thenew substationmayberequiredby2016/17,dependingonafinaldecisiontoproceedfromTrustpower.

Olderdistributionlineswillberepairedandrefurbishedasrequiredbyongoingconditionassessment.

Voltagesupportmeasures, includingthe installationofcapacitorsandvoltageregulators,willcontinuetobeappliedatstrategicpointsinthenetworktomaximiseperformanceoftheexistingassets,improvepowerqualityandreducemarginallosses.


Apartfromtheabove,nootherdevelopmentsareproposedthroughouttheplanningperiod.

5.7.3 HokitikaNetwork

Thecompletionof theWestlanddairy factorysupply in2002,comprisinganewWestpower2x15/20MVA66/33/11kVsubstationinHokitika,vastly improvedboththecapacityandsecurityofsupplytothetownofHokitikaandsurroundingdistricts,includingallofSouthWestland.ThiswillalsoprovideforcontinuingexpansionattheWestlanddairyproductsfactory,alongwithdownstreamgrowthinthedairyindustryingeneral,foratleastthenexttenyears.

TheWestlandDairyFactoryislikelytocontinuewithplansformajorsteploadincreasesthroughouttheplanningperiod,andthiswillrequiresomereconfigurationandpossibleaugmentationofthe11kVfeedercablesintotheplant,alongwithchangestothenetworkwithintheplantitself.

AspartoftheWCGRProject,Westpowerhassuppliedandinstalleda14MVarswitchedcapacitorbankconnectedtoan11kVcircuitattheHokitikasubstation.ThiswillprovidereactivesupportinordertomaintainandstabilisethevoltageofTranspower’s66kV transmission systemon theWestCoast. Theprojectwas fully fundedbyTranspower,whichtookovertheownershipofthesecapacitorsinJune2010.

Noothermajornetworkdevelopmentisplannedinthisareafortheremainderoftheplanningperiod.

5.7.4 SouthWestlandNetwork

AftertheamalgamationoftheGrey,WestlandandAmethystBoardsin1972,itwasfoundthattheinfrastructureassetsinSouthWestlandwereinaverypoorcondition.Considerableexpenditurehasoccurredoverthelast30yearstobringthereticulationsystemuptoanacceptablestandard.

Inaddition,anew33kVregulatorhasbeencommissionedatHarihari,andthishasprovidedsignificantadditionalcapacityintoareassouthofthatpoint,includingtheglacierregion.Also,threenewsingle-phaseregulatorshavereplacedtheexistingunitsatFoxtoincreasesecurityofsupplyforthatarea,alongwithprovidingadditionalcapacity.

MajorsteploadincreasesareconceivableintheFranzJosefareaifaresurgenttourismindustryshoulddecidetoinvestheavilyinnewaccommodationunits.Thishasbeenmadepossiblebytherecentdevelopmentofseverallarge,newsubdivisionsinthearea.

ItispossiblethattheSWGRmaybeimplementedin2018andthiswillinvolveupgradingasectionoftheHokitika-Harihari33kVlineto66kV,alongwithconversionoftheRoss,WaitahaandpossiblyHariharisubstationsto66kVoperations.ApossiblevariationtothisplaninvolvestheoptionofsupplyingtherelativelysmallWaitahaloadatalowervoltagefromnearbyRoss.Drivenbythepoorconditionoftheexistingasset,WestpowerhasalreadystartedtoupgradethepolestructuresbetweenRossandWaitahaandisplanningtoupgradetheHokitika-Rosssectioncircuitby2012andtheWaitaha-Hariharicircuitby2013.Thiswillbedoneinsuchawayastofacilitatefutureconversiontothehighervoltageifandwhenthisisrequired.

Securityofsupply isalwaysgoingtobeamajorconcerninthisarea,as it isfedbyavery longsingle-circuitlineandthebenefitofalternativesupplyfromlocalgeneration,particularlyfromTrustpower’sWahapopowerstation,isfastbecomingeclipsedbyloadgrowth.Theproposed6MWAmethystpowerschemebeingdevelopedbyWestpowerasajointventurewithourpartnerswillplayasignificantroleinimprovingsecurityofsupplytoSouthWestlandwhenitiscommissionedin2013.

5.7.5 WestpowerSubstations

WestpowercommissioneditsfirstgroundfaultneutraliserinGreymouthsubstationasatriallatein2010;thecommissioningdatehasbeenrescheduledforearly2012.

Duetonetworkinsulationcoordinationissues,thisislimitedtoamaximumconnectionperiodofoneminute,afterwhichthefaultedfeederistripped.


Calledagroundfaultneutraliser,thetechnologygreatlyreducesearthfaultcurrentsatthepointafaultoccursonthenetwork,whichamelioratesthelevelofthreattohumanlifeandriskoffire.ItalsoallowstheWestpowercontrolcentretomaintainpowersupplytohomesandbusinesseswhilefieldstaffaredispatchedtofixthefault.

Transientormomentaryfaultscanbeneutralisedaswell,eliminatingmanycasesofflickeringlightsandshort-terminterruptionstopowersupply.

Inthenextfouryears,WestpowerhasdecidedtoreplaceallKFEcircuitbreakerswithnewvacuuminterruptercircuitbreakerstoimproveitsnetworkreliability.Thishasbeendrivenbyanumberofrecentfailuresofthisequipment,whichcannotbepredictedoradequatelycoveredbyanenhancedmaintenanceprogramme.Atthesametime,theoldprotectionsystemswillbeupgradedwithnewdigitalrelaystoimprovesensitivityandselectivity.

5.8 Network Development Programmes

Capital Projects

5.8.1 ZoneSubstations

5.8.1.1 Twelvemonthperiod(over$30,000)

Adetaileddescriptionofallcapitalprojectsover$30,000scheduledforthenext12monthsisgivenbelow:

Enhancement

54012: Waitaha Zone Substation – Prepare site for Westpower Mobile Substation (WMS) access

Costs: $36,000

Project Justification Score: 45

Supplyingprimarilyafarmingarea,theWaitahazonesubstationsuppliesanareacoveringFergusonsBushinthenorth,WaitahaValleytotheeastandPukekuratothesouth.ItisproposedtopreparetheWaitahazonesubstationforWMSaccessthisyear.Thiswillinvolveallowingfora33kVand11kVconnectionpointtothezonesubstation,sitepreparation(earthmat,etc.)andas-builtdrawings.

Justification

AllowingtheWMStoconnecttotheWaitahazonesubstationwillensurecriticalmaintenancecanbeconductedinasafeandefficientmannerwhilemaintainingsupplytotheWaitahaarea.

ThishasprovedgreatlybeneficialatotherzonesubstationswhereaconnectiontotheWMShasbeeninstalled.Powercanbe retained to thearea thezonesubstationsupplies, reducingoutages.This isvital,asnootheralternativesupplyisavailablefromtheWestpowerNetworkifthereisanoutageorfaultattheWaitahazonesubstation.

Recently,whileurgentmaintenancewasneededtobecarriedoutontheregulatoratWaitaha,anoutagewasneededtotaketheunitoutofserviceandanotherwhentheunitwasreturnedtoservice.WiththeWMS,nooutagewouldberequired.

WiththeWMSabletobeconnectedtothezonesubstation,thiswouldallowabetterutilisationofaWestpowerresourceasopposedtoextracostsincurredwithfindinganalternativesupplyfortheWaitahaareasuchasagenerator.

TheWMSwouldbeabletobeusedforproposedfutureprojectsattheWaitahazonesubstationsuchastheCB1replacement/protectionupgradeandthereplacementofthethree-phaseRegulatorwithsingle-phaseunits.

ThisisalsothelastzonesubstationtohaveaconnectiontotheWMSinstalled.


Alternative Options Considered

Alternativeoptionswereconsideredincludingfeedingtheareaby11kVlinefromRossorHarihari,orusingageneratortosupplytheareaduringashutdownoroutage.Upgradingtheexisting11kVlinetomakeitcapableoffeedingtheWaitahaareawouldbeprohibitivelyexpensiveandusingtheWMSwouldbemorecost-efficientthanhiringagenerator,especiallyiftheWMSwasneededtobeconnectedforaprolongedperiod.TherearenohirecostsforusingtheWMSasopposedtohiringagenerator.

InstallingaconnectionpointfortheWMSwasconsideredtobethebestoption.

Replacement

44015: Wahapo Zone Substation – Replace Combiflex relay and protection settings upgrade

Costs: $108,000


Wahapo’sCB1andprotectionisbeingreplacedthisyear.ThisprovidesanidealopportunitytoreplaceT1olderCombiflexprotectionwithmodernSEL751Arelays.AlloftherelayswillcommunicatetoSCADAviaaSEL3530communicationprocessor.

Justification

ReplacementofT1olderCombiflexrelayswillbringtheWahapo zone substation up toWestpower’s currentstandardforzonesubstationtransformerprotection.

Aspartofthisproject,thecommunicationsequipmentis to be upgraded. Better fault analysis, protectionsettings,loadtrendingandSCADAcommunicationsaretobeachievedwiththeupgradingofprotectionwithmodernSELprotectionrelays.

TheSELrelayscanbeinterrogatedforfaultanalysisandquality of supply, providing improved operating datatothecontrolroomviaSCADA.ThesedataalongwithhistoricaldatafromSCADA,arealsoinvaluabletotheEngineers.


ReplacementoftheolderCombiflexrelayswiththemodernSELrelayswasconsideredtobethebestoption.TheWahapozonesubstationisoneofthefewremainingzonesubstationsleftwiththeolderCombiflexRelays.TheserelaysarenowageingandcomparedwithnewmodernSELRelays,theyhavelimitedprotectiongradingandnoremoteinterrogation.Withtheupgrade,thiswillbringtheprotectionatWahapoinlinewithothernewandupgradedWestpowerzonesubstations.

44016: Wahapo Zone Substation – Replace CB1 and Protection upgrade

Costs: $71,000


Mostofthezonesubstation11kVoutdoorcircuitbreakersareCooperOil-filledKFEtypereclosers.Overthelasttwoyears,areplacementprogrammehasbeeninplace,astheirsettinglimitationsareidentifiedasbeinglikelytocausenuisancetrippings.

Figure5.11-WahapoCombiflexRelayPanel


AnumberofzonesubstationsolderCombiflexprotectionrelayshavealsobeenidentifiedasneedingupgrading.Thesehavebeencompletedsimultaneouslyateachzonesubstations.

ItisplannedtoreplaceCB1withthenewVipervacuumreclosersandupgradetheprotectionwithamodernSEL351Arelay.Someequipmentforthisproject,liketheVipervacuumrecloser,hasbeenpurchased.

Justification

CooperKFEtypereclosersgivevariableandunreliableperformances.Theirsettingsselectionislimitedandtherehavebeenseveralauxiliaryswitchfailures.Theyhavehighmaintenancecosts,areunreliableduetohighdefectratesandarethecauseofunnecessaryoutagestocustomers.

Consequently,Westpower engineers have decided to replace all KFE type reclosers with themodern Vipervacuum Reclosers. These reclosers are practicallymaintenance free, except for periodic inspections. At thefeederlevel,reliablecircuitbreakeroperationiscriticaltomaintainingsupplytocustomersintheseareas.LatelytheCooperKFEReclosershavenotbeenprovidingthereliabilityexpected.

RemovaloftheCooperoil-filledbreakersalsoeliminatesthechanceofoilcontaminationintotheenvironmentasthesereclosersage.

Betterfaultanalysis,protectionsettings,loadtrendingandSCADAcommunicationsaretobeachievedwiththeupgradingofprotectionwithmodernSchweitzerEngineeringLaboratories(SEL)protectionrelays.


Alternative options were considered including on-going basic maintenance and refurbishment of the unit.Maintenancecostsoftheoil-filledreclosershaveincreasedconsiderablyinrecentyears.Reclosershavebeenrepairedwithnewpartsbutstillprovetobeunreliable,resultinginhighmaintenancecostsandunnecessarypoweroutages.

Modernvacuumreclosersarereliableandhaveminimalornomaintenancecosts.AplannedreplacementoftheCooperoil-filledrecloserswithnewviperrecloserswithSELprotectionrelayswasconsideredthemostcost-efficientoption.

44025: Kumara Zone Substation – Construct a new 11 kV switchroom

Costs: $760,000


The Kumara GXP is mainly required to provide a GridInjectionPoint(GIP)toTrustpower’s10MWKumarahydroscheme, but also supplies local load in the area fromGladstoneinthenorthtoJacksonsintheeastandDuffersinthesouth.

TheKumarahydroschemewasconstructedbyWestpowerinthemidtolate1970’s.The11kVswitchgearandassociatedequipmentwereinstalledinsidethepowerhousebuildingatthetimeofconstruction.Duetogovernmentregulatorychanges in the 1990’s Westpower sold their generationassets to Trustpower in 1999. Westpower retainedownershipoftheadjacentswitchyard.

Figure5.12-WahapoCircuitBreaker1


TrustpowerhaverequestedWestpowertoremovetheir11kVswitchgearfromthepowerstationbuildingby2013.TrustpowerwillberelocatingthegeneratorCB31tothegeneratorwellandWestpowerwillberelocatingCB’s1,2,3and38toanewcontrolroomintheswitchyard.

Justification

ThemaindrivingfactorforthisprojectisthatTrustpowerhasrequestedtheremovaloftheequipmentduetohealthandsafetyconcerns.Whenthepowerstationwasconstructed,thestaffwhomaintainedandserviceditwerebasedoff-site.NowthepowerstationbuildingisusedasaworkshopandofficeforTrustpowermaintenancestaffontheWestCoast.Theyhaverequestedthatthisbecompletedby2013.

Althoughhealthandsafetyarethemainfactorsforthisproject,constructionofthenewcontrolroomwillalsoensurethattheassociatedequipmentinstalledinthenewcontrolroomwillbethesameasotherneworupgradedSubstationsonWestpower’snetwork.Thishelpswithmaintaining standardisedoperationalproceduresandalsostandardisingthesparepartsrequired.ThisisapplicabletotheReyrolle11kVvacuumindoorMetalcladswitchgeartobeinstalled.Theyalsorequireminimalmaintenance,thusreducingmaintenancecosts.

Betterfaultanalysis,protectionsettings,loadtrendingandSCADAcommunicationsaretobeachievedwiththeupgradingofprotectionwithmodernSchweitzerEngineeringLaboratories(SEL)protectionrelays.

Design/drawings have been completed for this project. Out of the total costs of $760,000 for this project,Trustpoweristopay50%ofthesecosts.


Retainingthestatusquowasnotanoptionasadeadlineforshiftingoutofthepowerhousebuildingby2013hasbeenset.Westpoweralreadyownstheoutdoorswitchyardadjacenttothepowerstation.

Theonlyoptionavailableistoconstructanewcontrolroominsidetheswitchyard.

44027: Longford Corner – Upgrade regulator site

Costs: $70,000

Project Justification Code: 71

SituatedatLongfordCornernexttotheentrancetotheKokatahisettlement,theBrentford2MVAthree-phasemovingcoilregulatorprovidesvoltagesupporttothepredominantlydairyfarmingareaofKokatahi/Kowhitirangi.Manufacturedin1970,theexistingregulatorhasbeenexperiencingmoreregularfaultoccurrenceoflate,andsourcingsuitablepartsandsolutionstorectifythesefaultshasbeenquiteproblematic.

Itwasproposedtoreplacethecurrentregulatorwithtwo-singlephaseunits,which,combined,wouldincreasethecapacityoftheregulatorsitefrom2MVAto4MVAandprovideamorereliablevoltagesupporttothearea,withroomforfuturegrowth.However,inAugust2011,amajorfaultoccurredwiththeRegulator.Duetotherepaircosts,theageoftheunitandthefactthatitwasearmarkedforreplacementin2012/13,adecisionwasmadetoreplacetheunitwithtwo-singlephaseunits.ThesenewunitswereputinserviceinSeptember2011beforethestartofthe2011/12dairyseason.

Withtheregulatoralreadybeingreplaced,itisproposedtoupgradetheregulatorsiteinthe2012/13financialyear.


Justification

With thenewregulator installed,a redesignof thecurrentsitecannowbeachieved.A redesignof thesitewiththenewunitswouldmakethesitesafer.Thethreeexistingdisconnectorsatthissitearetheoldbrowndisconnectors.Theseolderdisconnectorshavecausedissueswhenoperatingandhaveincreasedmaintenancecosts.Theyhavebeenprogressively replaced in theWestpowernetworkwithnewor refurbishedSchneiderdisconnectors,andveryfewremainonthenetwork.

Withthereplacementoftheregulator,itsremoteoperationcanbeachievedthroughSCADAcommunications,whichwasunabletobeaccomplishedwiththeoldone.AlsodatasuchaspowerqualityandhistoryofoperationwillbeavailabletothecontrolroomviaSCADA.


Alternativeoptionswere considered, includingupgrading theexisting11 kV line to22 kVor33 kV, andon-goingregulatormaintenance.Upgradingtheexisting11kVlinetoahighervoltageprovedtobeprohibitivelyexpensiveand,duetotheageoftheunit,partswerehardtosource.TheoldregulatorhadreachedtheendofitsserviceablelifeandinstallationoftheCoopertypeunitskeepstheregulatorsinlinewithotherregulatorsitesinstalledonthenetwork.

With thenewregulatorsalready installed,anupgradeof thecurrent regulator sitewasconsidered thebestoption.

Development

Therearenodevelopmentcapitalprojectsplannedforthenext12-monthperiod.

5.8.1.2 TwotoFive-YearperiodProjects

Thissectioncontainsasummaryofallcapitalprojectstooccurinthenext2-5years:

Enhancement

Thereisnoenhancementcapitalprojectsplannedinthe2-5yearperiod.

Replacement

44020: Rapahoe Zone Substation – 33 kV disconnector upgrade (2014/15) - $26,000

The disconnectors on the CB2302 structure are to allow bypassing and isolation of the circuit breaker formaintenance.TheclearancebetweenthedisconnectorsandtheCircuitBreaker(CB) isnotsufficientforsafeaccessformaintenance.Thestructureistoberedesignedandupgradedtorectifythisproblem.Thisprojectisplannedtocoincidewiththe11kVmetalcladswitchgearreplacementinthe2014/15financialyear.

44022: Whataroa Zone Substation – Replace CB1 and protection relay (2013/14) - $90,000

KFEtypereclosershaveprovedtobeunreliableoflate.Theirsettingselectionislimitedandtherehavebeenseveralauxiliaryswitchfailures.CB1Cooperoil-filledreclosersaretobereplacedwithviperreclosers.ProtectionwillbeupgradedwithaSEL351Styperelay,enablingbetterfaultanalysis,protectionsettings,loadtrendingandSCADAcommunications.


44023: Rapahoe Zone Substation – Replace 11 kV Metalclad switchgear (2014/15) - $126,000

It is proposed to replace the last bulk oil 11 kV circuitbreakers on the Westpower network with new 11 kVReyrollevacuumreclosers.TheReyrollevacuumreclosersare installed throughout the Westpower network,maintainingastandardisedoperationalprocedurefor11kV indoor switchgear and also standardising the spareparts required. The Reyrolle vacuum reclosers requireminimalmaintenancethusreducingmaintenancecosts.

This project is planned to coincide with the 33 kVdisconnectorupgrade.CompletingbothprojectstogetherwhileusingtheWMStomaintainsupplyensuresreducedcosts associated with the WMS connection and betterutilisationofresources.

44024: Arnold Zone Substation – Replace CB3 and 4 with Vipers and upgrade protection (2015/16) - $300,000

KFE type reclosershaveproven tobeunreliableof late.Their setting selection is limited and there have beenseveral auxiliary switch failures. CB3 and 4 Cooper oil-filled reclosers are to be replaced with Viper reclosers.Protection will be upgraded with SEL351S type relays,enabling better fault analysis, protection settings, loadtrendingandSCADAcommunications.

44028: Whataroa Zone Substation – Replace CB1412 with WVE38X type recloser and T1 protection upgrade (2013/14) - $150,000

TheCooperRVEtype33kVoilrecloseristhelastofthistypeinstalledonthenetwork.ItisplannedtoreplacethisassetwithaWVE38xtypeVacuumrecloser.CB1412willthenbeinlinewithallofWestpower’sother33kVzonesubstationswhich,willensureastandardisedoperatingprocedureandonlyonesetofsparepartsrequiredtobemaintained.WiththereplacementofCB1andprotectionrelaysplannedforthesamefinancialyear,thisprovidesanidealtimetoupgradeT1protectionwithmodernSELrelaysinlinewithotherupgradedzonesubstations.

Waitaha Zone Substation – Replace regulator with single-phase units (2015/16 – 2016/17) - $194,000

Theexisting1MVAinductionregulatorwaspurchasedsecond-handfromTranspowerintheearly1990s.Themanufacturedateisunknownbutisthoughttobeinexcessof60years.Itisproposedtoreplacetheexistingthree-phaseunitwiththreesingle-phaseunits.

Duetoitscloseproximitytotheseaandthehighrainfallinthearea,theregulatorhasstartedrustingaroundthebottomandneedsattention.DissolvedGasAnalysis(DGA)testsalsoindicatethattheunitrequiresreplacing.Ithasbeendecidednottocarryoutanyexpensiverepairsonthisregulator.

Withthethreesingle-phaseunitsinstalled,theRegulatorwouldbeasperWestpower’sstandarddesign,(andthus spares are already in stock) andwould provide amore reliable voltage support, with room for futuregrowthinthearea.RemoteoperationcanbeachievedthroughSCADAcommunications,whichisunabletobeaccomplishedwiththecurrentregulator.SCADAcommunicationsarealreadyestablishedatthezonesubstation.$26,000hasbeenallowedfordesign/drawingsfor2015/16withtheremaining$168,000tocompletetheprojectin2016/17.

Figure5.13-Rapahoe11kVCircuitBreaker


Waitaha Zone Substation – Replace CB1 with viper and protection relay (2016/17) - $95,000

KFEtypereclosershaveprovedtobeunreliableoflate.Theirsettingselectionislimitedandtherehavebeenseveralauxiliaryswitchfailures.CB1Cooperoil-filledrecloseristobereplacedwithViperrecloser.ProtectionwillbeupgradedwithaSEL351Styperelayenablingbetterfaultanalysis,protectionsettings,loadtrendingandSCADAcommunications.

Development

Therearenodevelopmentcapitalprojectsplannedinthe2-5yearperiod.

5.8.1.3 Excess5yearsProjects

Enhancement

Hokitika Protection Upgrade - Design and installation and as built drawings (2018/19) - $315,000

TheHokitikazonesubstationwascommissionedin2002.Duetoprogressincommunicationsandtechnology,theexpectedlifeofdigitalprotectionrelaysis15years.Thesumof$315,000hasbeenallowedtocompletethisupgrade.

Replacement

Ross Zone Substation - Replace CB1 and 3 with vipers and upgrade protection (2017/18) - $126,000

ReplaceCoopertypeKFErecloserswithVipervacuumreclosersandreplaceprotectionwithSELrelays.

Ross Zone Substation – T1 protection upgrade (2017/18) - $95,000

ReplaceT1olderCombiflexprotectionwithamodernSELrelay.TocoincidewithCB1and3replacementandprotectionupgrade.

Dobson Zone Substation – Replace T6 (2019/20) - $735,000

ReplaceexistingDOBT6transformer.

Fox Zone Substation – Replace T1 (2020/21) - $735,000

ReplaceexistingFOXT1transformer.

Whataroa Zone Substation – Replace regulator with single phase units (2021/22) - $147,000

Replaceexistingthreephaseregulatorwiththreesingle-phaseregulators.

Ross Zone Substation - Replace regulator with single phase units (2021/22) - $147,000

Replaceexistingthree-phaseregulatorwiththreesingle-phaseregulators

Development

Therearenodevelopmentcapitalprojectsplannedinexcessoffiveyears.

5.8.2 MVSwitchgear

5.8.2.1 Twelve-monthperiod(over$30,000)

Detaileddescriptionofcapitalworksover$30,000inthenext12months.Someoftheseprojectsareon-goingthroughouttheentireAMPtimeframe:


Enhancement

56005: Install Automation to Various Disconnectors

Costs: $71,000


Remoteautomateddisconnectorshaveprovidedsignificantbenefitsto the network, and allow controllers to open and close switcheswithout having to call on standby staff. Each year, Westpower isupgradingitsstrategicswitcheswithautomatedunits.Twolocationshavebeenidentifiedthisyear.AllnewautomationistobeachievedwiththeuseofNTECloadbreakswitches.

Justification

NetworkfaultanalysishasidentifiedkeyareasontheWestpower11kVnetworkwhichrequireautomaticisolationoffaultsandremoteoperationoftieswitchestoretainsupplytobuilt-upareasandlargecustomers.

Theadditionofextraautomation to thenetwork improves systemreliabilityandfaultselectivity.TheNTECloadbreakswitchesarealsocapableofautomaticfaultisolationonsmallerspurlines.

TheNTEC loadbreakswitcheshavenoexternalmovingpartsandarethereforemorereliable.Theyarealsovirtuallymaintenancefree.

TheEntecloadbreakswitchescanbeinterrogatedforfaultanalysisandqualityofsupply,providingimprovedoperatingdatatothecontrolroomSCADAandtheengineersviaremoteaccess.


ThenextbestoptiontousingtheNTECwastofitmotordriveunitstodisconnectors.Thiswasrejectedasmotordriveunitshaveproventobeunreliablewhenrequiredforoperation.Theycansitforlongperiodsoftimeandexternal parts seize up.NTEChaveno externalmovingparts, have internal CT’s andVT’s, are competitivelypriced,andprovidefaultselectivityandfaultinterrogation.

InstallingNTECloadbreakswitchesatidentifiedlocationswasconsideredthebestoption.

56008: Fusing of Spur Lines by Feeder Classification

Costs: $40,000


AdetailedstudyhasbeenconductedtoclassifyallfeedersandlinesontheWestpowernetwork.Thereasoningtogive these feedersand lines classificationwas tohelp indeterminingwhat levelof securitywas requiredtomaintain supply to these feeders/lines. Factors taken into accountwith this study included feederswithhospitals,CBDs,commercialandlargeindustrialcustomers;feedersectionswithhighSAIDIhistories,criticalsubtransmissionlineswithnoalternativemeansofsupply;sectionsalreadyprotectedbyreclosers/sectionalisersorfused;andvegetation.Thesefeeders/lineswereclassifiedrangingfromF1(Critical),F2(VeryHigh)throughtoF5(Low).

Overthenextfewyears,itisplannedtofuseallpossiblespurlinesofffeeders/linesclassifiedasF1andF2.

Figure5.14-ENTECLoadBreakSwitch


Justification

Further investigationwillbedone todeterminewhichspur linescanbe fusedbyDDOFuses.This is tohelpmaintainsecurityonmainfeederLines,reduceSAIDI,andtohelpreducetheoutageareaaffectedandtobepatrolledwhenafaultoccursonthesespurlines.

Alternatives Options Considered

WhereitispossibletoinstallDDOfuses,previousexperiencehasshownthatDDOfusesareagoodoptionbothinperformanceonspurlinesandinprice.Quiteoften,itmakessensetofuseaspurline,ratherthanincurringthecostsofclearingtreesorlineupgrade.Largerspurlineswithgreaterloadwillbeidentifiedandconsideredforinstallationofarecloser(newspurlinereclosersbudget).

Replacement

46002: Replace Faulty Actuators - ENTEC load break switch or hydraulic actuator

Costs: $45,000


ExistingremoteautomateddisconnectorsfittedwithDulmisonmotordriveunitshaveproventobeunreliableandhavehighmaintenance/repaircosts.

Overthelastthreeyears,theseunitshavebeenreplacedwiththeENTECloadbreakswitches.TheENTECloadbreakswitcheshaveproventobemorereliable,andhavenoexternalmovingpartsandconsequentlyrequireminimalmaintenance.

Onlyoneunitremainsonthenetwork,whichisplannedforreplacementitthisyear.Thisunitisusedasatieswitchandhasbeencausingproblemsoverthelast12months.Currently,remoteoperationoftheswitchisnotpossible.Operationismanualonlyatpresent.

Thisisthelastyearforthisproject.

Justification

This location has previously been assessed as necessary. The replacementwith an Entec load break switchimprovesthenetwork’ssystemreliability,faultselectivity,qualityofsupplyanalysis,unplannedoutages,SAIDIandcustomersatisfaction.

AlloftheotherDulmisonautomateddisconnectorshavebeenremovedfromthenetworkandreplacedwithEntecloadbreakswitches,becausetheDulmisonunitsnolongerworkingorbeingunreliable.Thislastremainingunitisusedasatieswitchtoretainsupplytobuilt-upareasandlargercustomers.

TheEntecloadbreakswitchesarevirtuallymaintenance-free.Theycanbeinterrogatedforfaultanalysisandqualityofsupply,providingimprovedoperatingdatatothecontrolroomandtheengineersviaSCADA.

Removal of the last Dulmison unit with an NTEC ensures that all automated switches and tie switches arestandardised,thereforeonlyonestandardoperatingprocedureisrequiredandonlyonespareunitisrequiredaswell.


ThenextbestoptioninsteadofusingtheNTECwastofitmotordriveUnitstodisconnectors.ThiswasrejectedasMotorDriveunitshaveprovedtobeunreliablewhenrequiredforoperation.Theycansitforlongperiodsoftimeandexternalpartsseizeup.Entecshavenoexternalmovingparts,haveinternalCT’sandVT’s,arecompetitivelypriced,andprovidefaultselectivityandfaultinterrogation.


InstallingNTECloadbreakswitchesatidentifiedlocationswasconsideredthebestoption.

46003: Disconnector Replacements

Costs: $32,000


Disconnectorsnormallyfailduetodeteriorationoftheoperatingarmswithcorrosion,orfromanarcdevelopingacross two ormore phases. By identifying under-rated or defective disconnectors and replacing these, theincidenceofarcingfaultsshouldbereduced.

This isanongoingproject; fundsareallocatedeachyear.With thedisconnectormaintenanceprogramme inplacedisconnectorsare identified that aremore costefficientand safer to replace thanmaintain, thereforethenumberofdisconnectorstobereplacedvariesfromyeartoyear.Thisbudgetallowsfordisconnectortobereplacedwhentheyhavebeenidentifiedasreachingtheendoftheireconomicandserviceablelife.

46006: Ring Main Unit Replacement

Costs: $40,000


Anumberofoil-filled ringmainunitshavebeen identifiedas reaching replacementage.Abudgethasbeenallowedforaprogressivereplacementprogrammewhichwillseeoneunitperyearreplacedeveryfouryears.Furtherinvestigationisneededtodeterminethelocationtobereplacedinthisfinancialperiod.

Justification

Theolderoil-filledringmainunitshavebeenprogressivelyreplacedovertheyearswiththemodernABBSafelinkSF6Gasfilledringmainunits.Replacingtheoilfilledunitsreducestheriskofoilcontaminationtotheenvironment.ThenewerSafelinkunitscanberemotelycontrollediffittedwithamotordriveunitviaSCADA,givingthecontrolroommoreflexibilityinafaultsituationandreducingtheneedtocalloutaFaultmen.Replacingtheoil-filledunitwithanABBSafelinkringmainunitensuresthatthereplacementisthesameasothersreplacedorinstalledonthenetwork.Thishelpswithmaintainingstandardisedoperationalproceduresandalsostandardisingthesparepartsrequired.


Theoptionofrefurbishingandmaintainingtheexistingunitswasrejectedbecauseastheoil-filledringmainunitsage,theirmaintenancecostsincreasedandsparepartsfortheseunitsbecomehardertosource,andsomeoftheseunits,dependingontheirlocation,havehadtohavesectionsoftheoutsidebodyreplacedorrepairedduetoRust.

The ABB Safelink units are virtuallymaintenance-free and therefore, apart from periodic checks, they havereducedmaintenancecosts. InstallingaSafelinkunithelpstomaintainastandardisedoperationalprocedureacrossthenetworkandalsostandardisesthesparepartsrequired.Gradualreplacementoftheoil-filledRingMainunitswithABBSafelinkunitswasdeterminedtobethebestoption.


Development

66002: New Spur Line Reclosers on various Spur Lines

Costs: $40,000


ReclosersarebeingstrategicallypositionedthroughouttheWestpowernetworktoisolateproblematicspurlines,reducemainlinetrippingsandreduceinconveniencetoconsumersandSAIDI.

Reclosersarebeingfittedtospur lines,wherethenumberandsizeofconsumers are too great to fitDDOs. Three new locations have beenidentifiedthisyear.ItisproposedtoinstallKFMEtyperecloserstotheselocations.

Justification

NetworkfaultanalysishasidentifiedkeyareasontheWestpower11kVnetworkwhichrequiresautomaticisolationoffaultstoretainsupplytobuilt-upareasandlargercustomers.

Theadditionofextrarecloserstothenetworkimprovessystemreliability,faultselectivity,unplannedoutages,SAIDIandcustomersatisfaction.

Due to several recloser locationsonmain linesbeingupgraded toViper reclosers,Westpower currentlyhasenoughKFME reclosers in good condition in stock to re-useon thenetwork. TheKFME type reclosershaveprovidedgoodserviceonthenetwork.

InstallingKFMEtypereclosersonspurlinesdownstreamofViperreclosershashelpedinreducingtheoutageareaaffected ina fault, reducingmain lineoutagesand reducing thearea required tobepatrolled for faultfinding.


Forreliabilityandfault isolation,reclosersarethebestoption.Thenextbestsolutionof installingNTECloadbreak switcheswas rejected. The load break switches are not ideal formain line fault isolation, protectiongradingisrestrictedandtheoperationofthemainfeederrecloseratthezonesubstationisrequiredtotriggertheloadbreakswitchtoopen.Thismeansallcustomersonthatfeedersupplyisbeinginterruptedunnecessarilytoisolatethefaultedsection.

66005: Automate Capacitors at various Locations

Costs: $42,000


SupplytotheWestCoastingeneralisvoltage-constrainedandthisispartlyduetothelonginductivetransmissionlines.Whenalineoutageoccursduetofaultsorplannedmaintenanceevents,voltagecollapsecanoccurunlesssignificantsupportisavailablefromlocalgeneration;this,inturn,maydependonwateravailability.

Westpowerhave installed capacitors throughout the11kVnetwork tohelpmaintain voltage levels in areaswherethereisalargeindustrialloadorwherethereisloadonalongfeeder.Itisproposedtocarryoutadetailedinvestigationtodetermineasolutiontoautomateexistingcapacitorlocationsonthenetwork.

Figure5.15-ViperRecloser


Justification

Currently in areaswhere capacitors are installedwithlargeindustrialloads,voltagescanrisewhenthissignificantloadisreducede.g.atnightwhenproductionceases,orwhenplannedmaintenanceiscarriedoutandtheloadisturnoff.Atpresent,the capacitors are in service at all times. Withautomationof thesites, thecapacitorswouldbetakenoutofserviceswhenthevoltagesincreases,or by remote control from the control room viaSCADA. This will help Westpower maintain thevoltagewithinregulatedlimits.


As part of the investigation, all options will beconsidered.

66010: Amethyst Hydro – 33 kV connection

Costs: $200,000

Project Justification Score: Customer Driven

AspartoftheconstructionoftheAmethystHydroschemeaconnectiontotheSouthWestland33kVnetworkisrequired.Thiswillinvolvetheinstallationoftwonew33kVdisconnectorsandreclosers,andvoltagetransformerwillberequired.

Justification

ThisprojectiscustomerdrivenbyAmethystHydroLimited.Asstatedpreviously,aconnectionisrequiredfromthepowerstationtothe33kVWestpowernetwork.All(100%)ofthecostsfromthisprojectaretobepaidbyAmethystHydroLimited.

5.8.2.2 Twelve-monthperiod(under$30,000)

A summary of capital projects under $30,000 in the next 12months,someoftheseprojectswillbeon-goingthroughouttheentireAMPtimeframe.

Enhancement

56004: Distribution Intelligent Fault Isolation System – Study/design - $2000

AdetailedstudyofWestpower’snetworkistobecarriedouttodeterminethebestlocationforreclosers,GEDO’s,sectionalisingdisconnectors, automated disconnectors, etc. for isolation offaults and automatic restoration of supply to customers. Thenumber of customers affected, length of line and possiblealternative points of supply are some of the items to beconsideredinthestudy.

Figure5.16-CapacitormountedinsidePad-mountedcabinet

Figure5.17-EarthFaultIndicator


56006: Fit Earth Fault Indicators - $6000

Earth fault indicatorsare tobefitted tochosenunprotectedcables todetectcurrentpassagedue toa faultdownstream.Thesewillallowfaultcrewtoquicklyidentifyafaultycabletospeeditsisolationandrestorethefeederpromptly.

Replacement

46004: Remote Locations Battery Replacement - $6000

Afive-yearreplacementprogrammeisinplaceforbatteriesatremotelocationsinthenetwork.Thisisanon-goingprojectandfundshavebeenallocatedtoachievethis.

Development

66001: New Main Line Recloser Sites (Dilmans) - $25,000

MainlinereclosersarebeingstrategicallypositionedthroughouttheWestpower network to reduce the number of consumeroutagesincurredduringfaults,thusreducingSAIDI.

AViperistobeinstalledintheDilmansareathisyear.Thiswillallow for the DIL4 recloser and associated equipment to beremovedfromTrustpower’sDilmanspowerstation.

66007: New Disconnectors - $27,000

Several new disconnectors are to be installed to furthersectionalisethenetworkandtoreducethenumberofcustomersaffected by 11 kV switching operations. These disconnectorinstallationswillalsoassistinthelocationoffaults.

66008: New Ganged DDO Fuse Unit Locations - $10,000

Ganged DDO fuse units (Figure 5.19) are being strategicallypositioned throughout the Westpower Network to isolateproblematic spur lines, and to reduce inconvenience toconsumersandSAIDIoutageminutes.

5.8.3 SCADA,CommunicationsandProtection


Detaileddescriptionofallcapitalprojectsover$30,000inthenext12months:

Enhancement

Noplannedenhancementprojectexceeds$30,000.

Replacement

Noreplacementprojectexceeds$30,000.

Figure5.18-PolemountedRecloser

Figure5.19-GangedDDOfuse


Development

67011: South Westland, IP Expansion VHF Digital Radio Costs: $70,000

This isaprojectwillbebrokenup intoseveral smaller jobs, includingextending the footprintofWestpowerdigitalIPnetworksouthofGreymouth.WiththisexpansionofthedigitalIPfootprint,anumberofcurrentzonesubstationsandpoletopdeviceswillnowbeabletobeconvertedtoIP.

Justification

Convertingthesesitesallowsremoteengineeringaccess,real-timeSCADAmonitoringandprotectionsignallingifrequired.

67036: Comms to New 11 kV Switch Room Kumara: $40,000

Justification

TrustpowerhaverequestedWestpowertoremovetheir11kVswitchgearfromthepowerstationbuildingby2013.TrustpowerwillberelocatingthegeneratorCB31tothegeneratorwellandWestpowerwillberelocatingCB’s1,2,3and38toanewcontrolroomintheswitchyard.

WiththeconstructionofthenewswitchroomatKumara(seeStationsproject44025)communicationswillhavetobeinstalledtoallowremoteengineeringaccess,real-timeSCADAmonitoringandprotectionsignalling.


Retainingthestatusquowasnotanoptionasadeadlineofshiftingoutofthepowerhousebuildingby2013hasbeenset.Westpoweralreadyownstheoutdoorswitchyardadjacenttothepowerstation.

Theonlyoptionavailableistoconstructanewcontrolroominsidetheswitchyard.

67037: Amethyst 33 kV Connection: $100,000

Justification

With the construction of the new power station at Amethyst, communicationswill have to bemodified toallowremoteengineeringaccess,real-timeSCADAmonitoringandprotectionsignalling. Thismodificationtocommunications systemwill require constructionof anew radiopath toMtHercules that is capableof therequirementsforprotectionsignalling.

5.8.3.2 ProjectsoverFive-Years

57001: Modification of the Load Control System - $10,000

TheWestpower loadcontrol system isacritical componentof theSCADAsystem. Withchanges in thewayTranspowerchargeWestpower,loadcontrolsneedtobemodifiedtosuittheirrequirements.

57003: Mt Bonar Repeater - $4000

Generalhardware/sitedevelopmentforthisradiorepeater.

57011: SCADA Critical Spares - $15,000

Asnewtechnologiesarepurchased,spareunitsarerequired.

57012: IP Firewall/Security/Remote Secure Access - $6000

Withtheincreasednumberofradiolinksusingpublicbandfrequencies,securingofthecommunicationsnetwork,dataandequipmentfromhackersandvirusesneedstobeaddressedandkeptcurrent.


57022: SCADA Master Station - $10,000

TheSCADAmastersystemneedstobekeptuptodatewithsoftwarechangestoenablethesystemtohavemaximumfunctionalityandtoextendthelifeofthecurrentsystem.

57025: Inter-Control Centre Communication Protocol Feed from Transpower - $10,000

TranspowerhaveidentifiedthatanInter-ControlCentreCommunicationProtocol(ICCP)linktogenerators/ELBs/directlyconnectedcustomersisastrategicpriority.

Development

67009: Whataroa Communications - $30,000

With theplanned zone substationprotection relay upgrade (seeproject 44022), significant communicationsmodificationstothesubstationwillberequiredforremoteengineeringaccess,real-timeSCADAmonitoringandprotectionsignalling.

67011: SCADA Off-Site Backup - $5000

ForextrasecurityoftheSCADAsystem,off-sitebackupofdataneedstobeaddressed.

67013: Paparoa move all Antennae to Triangle Tower - $15,000

WiththechangeinratingofthePaparoasitebyKordiatoaG2site,Westpowerstaffcannownolongerclimbthelargetowertomaintaincriticalaerialequipment.Itisproposedthatallaerialsbemovedtoastrengthenedtriangletower,asourstaffhaveaconcessiontoclimbthistower.

67014: Fast IP Comms to Recloser Sites for DIFIS Project - $20,000

Investigateandimplementthebestcommsoptionsforallnewpoletopcommssites.Thisisrequiredfortheimplantation ofDistribution Intelligent Fault Isolation System (DIFIS). The new circuit breakers and switchesbeinginstalledintoWestpower’slinesnetworkrequireanewhigh-speedcommunicationslinktoeachsite.Thislinkwillgivethecontrolsystemtheabilitytoautomatically,reconfigurethepowerflowthroughthenetworkwithintheallowedtimestoisolatethefault,thussavingvaluableSAIDIs.

67017: International Standard 61850 Rollout - $10,000

WiththeplannedchangetotheInternationalStandard61860communicationsprotocol,newequipmentwillberequiredfortestingandimplementation.

67018: Meter Reading - $10,000

Thenewmeteringequipmentmodificationtothenetworkandreadingsoftwareneedstobeinstalled.

67019: VMWare Server Configuration/Equipment - $10,000

AsthecreationofnewvirtualserversisrequiredonVMWarehardware,licencesandextraequipmentmayneedtobepurchased.

67026: Blue Spur Repeater Site - $30,000

MetservicehavebuiltanewrainradaratBlueSpur.Thisnewsiteistobedevelopedasarepeatersite.

67031: Comms to MV Switchgear Disconnector Automation and New Reclosers - $30,000

Anallowance for threenewdisconnectors, threeKFMEand fourViper reclosershasbeenallocated fornewcomms.


67033: Comms to Automate Capacitors - $15,000

ThisisanallowancefornewcapacitorsthataretobemonitoredbySCADA.

67034: Comms to Ring Main Unit’s - $20,000

AnallowancefornewRMU’stobemonitoredbySCADA.

Inspection, Service and Testing

BelowisalistofallmaintenanceworkstobecompletedforSCADACommsinthenext12months.Theseareallon-goingbudgetsthatarecarriedoutyearlyforthedurationoftheAMPperiod.

17001: Communications Configuration in Server Room - $6000

AsequipmentinthemainserverroomiscriticaltoSCADAasumhasbeenallowedforISTofthisequipment.

17002: Abbey Support Contract - $4000

ThisisanannualmaintenancefeeforAbbeySystemssupport.

17003: Power System Consultants Support Contract - $20,000

ThisisanannualmaintenancefeeforPowerSystemConsultants(PSC)support.

17004: Realflex Datac Support Contract - $18,000

ThisisanannualmaintenancefeeforRealflexDatacSupportContract.

17005: SCADA General Licences - $19,000

RockwellandTelemecaniquenlicenseagreementsrequiredforSCADAsystemtooperate.Alsoacontingencyhasbeenallowedforothersoftwarelicensesasneeded.

17006: MED Radio Licences - $12,000

AnnuallicencefeestotheMinistryofEconomicDevelopmentfortheradiofrequenciesusedbyWestpower.

17007: Repeater Site Co-locations Fees - $90,000

AnnuallicensefeestothesiteownersforradiorepeatersitesusedbyWestpower.

17008: General Battery Testing and Replacement - $30,000

Most control devices in the network are supplied from batteries. These are regularly discharge tested andwhenfoundtobenearingtheendoftheirlife,arereplaced.Thisbudgetallowsfortestingnewbatteriestobepurchasedwhenrequired.

17009: Continual Document and As-build all Comms - $6000

AnallowanceforcontinuedimprovementofWestpower’scommunicationsrecords.

17010: Abbey Sites SCADA, Comms, I,S&T - $20,000

SumforthemaintenancevisitstoWestpowerpoletopsitesthesesitesareusuallyAbbeysitesbutmoreIPpoletops.

17011: Repeater Sites SCADA, Comms, I,S&T - $30,000

SumforthemaintenancevisitstoWestpowerrepeaterSites.


17012: Zone Subs SCADA,Comms, I,S&T - $40,000

SumforthemaintenancevisitstoWestpowerzonesubstations.

17013: Mt Bonar RSM 25 kHz Frequency Change - $15,000

Configuresitetobecompliantforchancesto25kHzfrequencyChangerrequiredby1November2015.

17014: Mt Kak RSM 25 kHz Frequency Change - $15,000

ConfiguresitetobecompliantforChancesto25kHzfrequencyChangerrequiredby1November2015.

17015: ICCP I,S&T - $35,000

WiththenewproposeddirectICCPlinktoTranspower,anannualconnectionfeeisrequired.Transpowerhasprovidedanestimatedoffuturecosts.

5.8.4 Subtransmission

5.8.4.1 Twelve-monthlyperiod(over$30,000)

Replacement

40005: HKK-WTH 33 kV Pole Replacement

Costs: $780,000 Project Timeline: April 2012 – December 2012


ThehardwoodpolelinebuiltoriginallybytheStateHydroCommissionin1965betweentheHokitikasubstation(whichreplacedtheoldArahurasubstation)andtheHariharisubstationhasreachedtheendofitsserviceablelife.Manyofthepolesareinpoorcondition.TwoyearsagoaprojectwasinitiatedtoreplacethepolesbetweenWaitaha andHokitika. A significant section of pole replacement has been completed between theWaitahasubstationandtheRosssubstation;however,thependingconductorupgradebetweenWaitahaandHokitikahashastenedtherestofthepolereplacementprogramme.Originallyplannedtobecarriedoutoverthreeyears,thisprojectisnowtobecompletedbyDecember2012tocoincidewiththecommissioningoftheAmethystHydropowerstation.Thescopeofthisprojectwillincludethedesignandsubsequentreplacementofallhardwoodpoles andwill be reconfigured to complywith the standard66 kV17mStresscretedeltapoledesign. It isestimatedthat$780,000willbespenttocompletetheproject.

It must be noted that a number of poles between the Waitaha Substation and the Amethyst PowerStation that may need replacement while outages are still possible. Several poles (yet to be identified)may not be able to be replaced using live line techniques, and with outages likely to be few and farbetween when Amethyst power station becomes operational, pole replacement would become extremelydifficult.

Justification

TheSouthWestlandareafromRosstoParingaisdependentonsupplyfromthis33kVspurline,withonlylimitedredundancyinareasaroundtheWahapopowerstation.Althoughcapableofwithstandingdesignloads,thepoorconditionofmanyofthepolescouldfailifsubjectedtoextremeweathereventsfrequentlyexperiencedinSouthWestland.Failureofanyofthesepolesinanunplannedeventcouldposeseriousaccessissuesandsignificantlyextendedoutagetimes.TheintroductionoftheAmethysthydroschemewillprovideadditionaldriversfortheproject,particularlytoprovidesuitablesupportforthestringingoftheheavyOxygenconductor.



Noalternateoptionsareavailable,asthissupplytoSouthWestlandisaspurlinewithonlylimitedalternatefeedvialocalgeneration.

40006: Replace Waitangitaroa River Crossing

Costs: $43,000 Project Timeline: May 2012 – June 2012

Thegradualincreaseofriverbedgravelbeneaththe33kVlinecrossingtheWaitangitaroaRiverinSouthWestlandhascompromisedthepreviouslycompliantclearancetotheriver.Areportwascommissionedin2011toobtainthemosteffectivemethodtoregainsufficientclearance,withtherecommendationtoreducethespanlengthsbyinstallingapiledstructureinthemiddleoftheriverbeingadopted.Thisoptionwouldservetoincreasethegroundclearancetoalevelwheretheeffectsofriverbedbuild-upisminimisedandalsoreducetheexcessiveloadsonallexistingequipment.

Theexistingspanis343mlongwhich,byanystandards,isalongspan.Thisismadeworsebythefactisthespanisessentiallyflat,meaningallgroundclearanceisachievedbyusingtallpolesorincreasingtheconductortensiontoreduceconductorsag.

The existing structures at each end of the river crossing span are in relatively good condition. They areapproximately13.7mlongonwoodenpileswhichsupportthepolesoasthefulllengthofthepoleisutilised(thebottomofpoleisatgroundlevel).Cross-armsareSteeltrefoiltypeasusedontheFoxtoParingaLine.Thesepoleswillnotrequireupgradingtoimprovethegroundclearanceissues.

Justification

TheSouthWestlandareafromWhataroatoParingaisdependentonsupplyfromthis33kVspurline,withonlylimitedredundancyinareasaroundtheWahapopowerstation.Withtheeverincreasingriseofriverbedgravel,theclearancefromthewatertothelinewillbecomeless,toapointwheredebrisfloatingdowntherivercouldstrikeanddamagetheconductors,resultinginlengthyoutagesforalargenumberofconsumers.


Re-tensioningtheconductortoachievetheregulatory6.5mgroundclearancewasconsidered;however,thiswouldincreaseloadingsonequipmenttoanunacceptablelevel.Adesktopstudyonthissectionoflineshowsthatalthoughthestructuresappearsound,theyareoverloaded.Thepolesoneachendoftherivercrossingspanareatriskshouldtheveryworstdesignweatherconditionseventuate.Forthesereasons,retensioningtheconductorshasnotbeenadopted.

Replacingtheexistingpoleswithtallerpoleswasalsoconsidered,howeveritwasdecidedthatthiswouldbeashorttermfixandalthoughtheywouldgainacceptablegroundclearance,thespanswouldnotbeanymoresecurethanatpresentandtheconductorwouldremainoverloaded.

40012: Replace Waiho River Crossing

Costs: $50,000 Project Timeline: May 2012 – June 2012

ThecontinualriseoftheWaihoRivernearFranzJosefandthesubsequentriseofthefloodbankhasagainbeguntothreatenthesecurityofthe11kVand33kVsupplyingSouthWestland.Todeterminethebestmethodtoensurethatallregulatoryclearancesareachieved,adesigniscurrentlyunderway.Thisdesign,whichmayincludeplacingpolesonraisedearthworksonbothsidesoftheriverwillbecompletedinFebruaryandwillincludeallpotentialmethodstoalleviatetheclearanceproblem.Acontingencysumof$50,000hasbeenallocatedforthiswork.


Justification

TheSouthWestlandareafromFranzJoseftoParingaisdependentonsupplyfromthis33kVspurline,withnoredundancyinthearea.Withtheeverincreasingriseofthefloodwall,theclearancefromthetopofthewalltothelinewillbecomeless.Shouldthisworknotbecarriedout,theriskofheavyequipmentusedinraisingthefloodwallstrikingthelineisveryreal.


Althoughthedesignphasewillidentifyalloptionsforraisingtheline,itappearsatthistimethatconstructingraisedearthworkseithersideoftheriver,independentofthefloodwall,maybethebestoption.

40012: GYM-KUM 66 kV Pole Replacement

Costs: $40,000 Project Timeline: February 2013

In previous years, poles on theGYM-KUM66 kV cct have been replaced in sections. However, a change inreplacementstrategywillseepolesreplacedonlywhenthepoleshavebeenproventobeattheendoftheirserviceablelife.Acontingencysumof$40,000hasbeenallocatedtoallowthereplacementoffourstructures.

Justification

Builtin1977(approaching35yearsold),theGYM-KUM66kVcctiscriticaltothesecurityofsupplytoGreymouthandthesurroundingareas.Shouldapolefail,particularlyinsomeofthemoreremoteareas,securityofsupplytoGreymouthcouldbecompromised.


Asmentioned,thealternativetoapole-for-polereplacementstrategyisthatofsectionsoflinebeingreplacedasa‘project’.Asthisstrategyisnolongersupported,therearenootheroptionsavailable.

40013: Sub-transmission Condemned Pole Replacement

Costs: $30,000 Project Timeline: April 2012 - March 2013

Previously,mostsubtransmissionpolesreplacedwereincludedinprojectsthatreplacedsectionsoflinedeemedto be reaching replacement criteria.With the shift in assetmanagement strategy to bemoremaintenancefocused,onlysub-transmissionpolesthathavebeenproventohavereachedtheendoftheiroperationallifewillbereplaced.Toprovethis,thoroughinspection,includingscanningandanalysiswiththePortaSCANXBSpoledensityscanningsystem,willberequired.

Fiftyfivesubtransmissionpoleshavebeenidentifiedtobeinpoororworseconditionusingthetraditionaldigandprobemethodofassessment.ConsiderationmustbegiventoPortaSCANXBSresults,whichareverylikelytosignificantlyreducethenumberofpolesrequiringreplacementduetothemoreaccurateassessmentthatthePortaSCANXBSprovides.

Fromtimetotime,itmaybemoreprudenttoreplaceseveralpolesinasectionoflineifconsiderationssuchasreconfiguration,landownerissuesoroutagerestrictionswarrantthis.

Justification

Toensuresafetytoworkersandthepublic,andtoreducefaults,polesmustbereplacediffailureisimminent.Replacementmustbebalancedwith gaining themaximum life frompoles, hence theemphasis ondetailedassessmentbeforepolesarechangedout.


Polesattheendoftheiroperationallivesmustbereplaced.Therefore,noalternativeoptionsareavailable.



10001: Sub-transmission Access Road Maintenance


Keepingaccesstostructuresopenandclearisveryimportantformaintenanceandattimesoffaults.Sometimesaccesstostructurescanbeblockedbyslipsorwashoutsandneedclearing,generallyrequiringexcavatorstocarryoutthework.Occasionallyaculvertmaywashoutandrequirereplacement,furtherinhibitingaccesstostructures.Thebudgeted$44,000isacontingencyforsuchevents.

Justification

Attimeof faults, routine inspectionsor linemaintenance, it is crucial thataccess is clearandcrewscanbedeployedtostructureswithouthavingtomanoeuvrearoundobstaclesortoclearovergrownvegetation.Aswellas speedingupentry to structures, thehealthandsafetyaspectofkeepingaccesswaysclearmustbeconsidered.


Forthereasonslistedabove,accesstostructuresmustbecleared;therefore,therearenoalternativeoptions.

10011: River Protection Works

Costs: Subtransmission - $50,000 distribution - $66,000

Project Timeline: April 2012 - March 2013

ThefrequentheavyraineventsexperiencedontheWestCoastcanoftencauseriverstofloodandthreatensub-transmissionlines.AreasofconcernaretheTaramakauRiverandseveralriversinSouthWestlandthathavethepotentialtobreachtheirbanksandre-routeintothepathofWestpower’sstructures.Forthis,acontingencysumhasbeenallocatedforriverprotection,whichisgenerallyintheformofrockprotection.

Justification

Toensurestructuresareprotectedfromthethreatsthatrivererosionposes,fundsmustbeallocatedtoensurefloodprotectionworkiscarriedoutbeforeanextremeevent.Areasofconcernaregenerallyidentifiedduringroutineorspeciallineinspections.


Forthereasonslistedabove,structuresmustbeprotectedfromthethreatoferosionandtherefore,therearenoviablealternativeoptions.

10012: Weed Spray Access Tracks and various Line Routes

Costs: $60,000 Project Timeline: January 2013 - February 2013

Weedsprayingoftracksandlinerouteshasbecomeanintegralpartofthevegetationcontrolprocessthroughoutthenetwork. In recent years,overgrown trackshavebeenopenedupallowing safevehicleaccess tomostsub-transmissionstructures thusenablingmoreefficientpatrols,access forconditionassessmentand fasterresponsetime incaseof faults. These tracksneed to remainclearand inmostcases regular sprayingwithagrichemicalskeepsthebrushandscrubatbay.


Justification

Aswiththeaccessroadmaintenanceproject,weedsprayingneedstobecarriedoutannuallytoallowspeedyaccesstostructuresandalsotokeeptroublesomescrubthatmaycontactthelineatbay.


Forthereasonslistedabove,accesstostructuresmustbekeptclear.Clearingscrubwithachainsawcouldbeseenasanoption;however,thatmethoddoesnotcontaintheregrowthrateasefficientlyassprayingagrichemicals.Inaddition,clearingscrubwithachainsawisslowandcumbersome.

Tree Trimming and Felling


TheintroductionoftheHazardsfromTreesRegulations2003placedasubstantialemphasisontrimmingandremovingtreesnearpowerlines.From2003tothepresentday,significantprogresshasbeenmadeinkeepingvegetationclearoflinesontheWestpowernetwork.ThisactivityhashelpedtoreduceSAIDI’sandhasvastlyimprovingpublicsafety.Asmentioned,manytreeshavebeenremovedfromnearlinesandwillnotrequirearevisit,andalargenumberoftreeshavebecometheresponsibilityofthelandowner,havingreceivedthefirstcut.InaccordancewiththeHazardfromTreesRegulations2003,theselandownerswillberequiredtofundthenexttrim.Thefactorslistedabovearereflectedinthereductionofthetreetrimmingfundingintheupcomingyears.

Justification

ToadheretotheHazardsfromTreesRegulations2003andtheElectricitySafetyRegulations2010,Westpowermustcontinuetoadministerandcarryouttreetrimmingworktoanacceptablelevel.


Asthedriversforthecontinuedtrimmingandfellingoftreesissafetyandregulatory,therearenoalternativeoptionsavailable.

Sub-transmission Condition Assessment


Conditionassessmentofalllineshasbecomeincreasinglyimportant,particularlywiththerecentlyintroducedmaintenance focused assetmanagement strategy. To ensure optimum life levels are gained for each asset,particularlypoles,assessmentneedstobetimelyandaccurate.

Thereareinexcessof700hardwoodsubtransmissionpolesonthenetwork,althoughsomearereasonablynew(68ontheKUM-KAW66cctconstructedin1997).Mostoftherestareagingandwillrequirecarefulandanalyticinspection,includingscanningwiththerecentlyimplementedPortaSCANpoledensitymeasuringdevice.

Givenafive-yearinspectionschedule,140woodensubtransmissionpoleswillrequiredetailedinspectionandassessmentannually. In addition to thewoodenpoles, thereare1861 concrete sub transmissionpoles thatrequireregularinspection.Asthereisnorequirementforundergroundinspection,inspectionandassessmenttimesforthesearefarlessthanwoodenequivalents;however,analysisofassessmentresultsremainssimilar.

Justification

Bestpracticeassetmanagementcallsforregularinspectionandassessmentofassets,andthereforeinspectionofsub-transmissionassetsisrequired.Theconditionassessmentprogrammeallowsidentificationofdefectivecomponentsandaidsinforecastingassetlives,providingaplatformforreplacementplanning.



Asthedriversfortheconditionassessmentofsubtransmissionassetsaresafetyandregulatory,therearenoalternativeoptionsavailable.

Sub-transmission Line Patrols


Overthe lastthreeyearsthenumbersofsub-transmission linepatrolshaveprogressively increasedwiththeuseofpreventativemaintenancescheduling.Manydefectshavebeenfoundandcorrectedbeforeafaulthasoccurredandtheresultingreportshaveprovedinvaluabletoprovideasnapshotofthestateofeachlineatanytime.

Apatroldiffers fromaconditionassessment inspectionas farasapatrol isabriskvisit toeachstructureoraccesswayandavisualinspectionisallthatisgenerallyrequiredwithanydefectsoranomaliesrecorded.

Aswellasroutinepatrolsotherpatrols,suchasafterextremeweatherevents,arealsocarriedoutandaidinpotentialfaultidentification.TheallocatedfundingallowsforthePreventativeMaintenance(PM)schedulestobecarriedoutandacontingencyforanyspecialpatrolsthatmayberequired.

Justification

Toensuresub-transmissionassetsremainsafeandoperational,regularpatrolsarecritical. Resultingreportscontaining information such as defective components, potential landowner issues, access issues and safetyconcernscangenerallybeaddressedbeforetheybecomeaproblem.


Thepatrollingoflinesonaregularbasishasbeenincarriedoutinearnestonlyrecentlyandhasalreadyprovidedinformationthatcouldhavepreventedfaultsand/orsafety issues. Toceasecarryingoutthesepatrolscouldcontravenepublicsafetyregulationsandcompromisesecurityofsupply.

General Maintenance of Subtransmission Lines


Asum is included in thebudget foranygeneral linemaintenancework thatmayneed tobecarriedoutonanyofthesubtransmissionlinesoccasionally,minormaintenanceisrequired,suchasstepboltreplacements,replacementofdamagedearthleadsormaybearustyclamp.Asum,therefore,needstobeallocatedtoallowforthiswork.

Justification

Astheconditionassessmentandlinepatrollinghasbeenprogressivelyrampedup,sohastheidentificationofthistypeofmaintenancework.


Asmostdefects identifiedrequire remedialaction,noalternativeoptionsareavailable toensurea safeandreliablesub-transmissionsupply.


Enhancement

50002: HKK-WTH 33 kV Conductor Upgrade

Costs: $1,800,000 Project Timeline: April 2012 – December 2012


AmethystHydroisbuildinganewhydroschemeontheAmethystRivernearHarihariinSouthWestland.Thishydroschemewillgenerateupto6MWofelectricityintoWestpower’s33kVlinenearHarihari.ThevastmajorityofthisgenerationwillneedtobetransmittednorthwardtoHokitika,adistanceofsome65km.

Anassessmentwascarriedout todeterminethe losses involvedshouldtheexistingDogACSRconductorberetained.Theresultsofthisassessmentrevealedthatalargenumberoflosseswouldbelikely,whichpromptedastrategicreviewtodeterminethebestmethodoflossavoidanceonthecircuit.ItwasdecidedthatstringingthelargercapacityOxygenAAACfromtheWaitahasubstationtoHokitikawouldbethebestoptiontohelpensuretheoptimumtransmissionconfiguration.


Fouralternativeoptionswereconsideredforthisproject:

• Existingconductortype(Dog)energisedat33kV,

• UpgradingthelineconductortoOxygenandenergisedat33kV,

• Existingconductortype(Dog)energisedat66kV,

• UpgradingthelineconductortoOxygenenergisedat66kV.

5.8.4.2 TwotoFive-YearperiodProjects

Replacement

Mapourika, Replace Substandard Poles (2015-2018) $20,000 p/year

Condition assessment revealed thatmost of the poles on the Hendrix cable section of line traversing LakeMapourikaareinverypoorcondition.AsubsequentinspectionwiththePortaSCANXBSpolescanningsystemdisputedthetraditionalmethodsandfoundthemajorityofpolestohavemanyyearsofoperationalliferemaining,howeverseveralwillneedtobemonitoredandpossiblyreplaced.

Warrens Paddock - Replace structures (2013-2014) $50,000

Thewooden33kVand11kVstructuresatWarrenspaddocknearTaylorvillesupportanintegrallinktotheNorthviatheRapahoeandNgaheresubstations.Inparticular,the33kVlinetoRapahoedoesnotproviden-1security,andtheminesandsurroundingtownshipsrelyheavilyonthissupply.Atpresent,thestructurescouldbedeemedtheweakestlinkforthiscriticallineandalthoughPortaSCANresultindicatethepolesareinreasonableconditionandshouldwithstandnormalloadsplaceduponthem,thecriticalityoftheagingstructuresdeemthisprojectnecessary.Atminimalcost,risktothiscircuitcouldbeachievedbyreplacingthestructures.Itisintendedthatadesignwillbecarriedout2012-13toallowamoreaccuratecostassessment.


5.8.5 Distribution


Replacement

41064: Distribution Condemned Pole Replacement


Aswiththesub-transmissionpoles,mostdistributionpolesreplacedhavebeenincludedinprojectsthatreplacedsectionsof line thatweredeemed tobe reaching replacement criteria.With the shift inassetmanagementstrategytobemoremaintenancefocused,onlydistributionpolesthathavebeenproventohavereachedtheendoftheiroperational lifewillbereplaced. Toprovethis,thorough inspection, includingthescanningandanalysiswiththePortaSCANXBSpoledensityscanningsystemwillberequired.

Six hundred and twenty twodistributionpoles havebeen identified tobe in poororworse conditionusingthetraditionaldigandprobemethodofassessment. ConsiderationmustbegiventoPortaSCANXBSresultswhichwillmostlikelysignificantlyreducethenumberofpolesrequiringreplacementduetothemoreaccurateassessmentthatthePortaSCANXBSprovides.

Fromtimetotimeitmaybemoreprudenttoreplaceseveralpolesinasectionoflineifconsiderationssuchasre-configuration,landownerissuesoroutagerestrictionswarrantthis.

Justification

To ensure safety toworkers, the public and to reduce faults, polesmust be replaced if failure is imminent.Replacementmustbebalancedwith gaining themaximum life frompoles, hence theemphasis ondetailedassessmentbeforepolesarechangedout.


Polesattheendoftheiroperationallivesmustbereplaced,thereforenoalternativeoptionsareavailable.

41002: Blackball-Atarau Rd - 11 kV pole replacement

Costs: $80,000 Project Timeline: July 2012 - August 2012

The 11 kV line fromBlackball through toMoonlight/Atarau has beenprogressively replaced over a numberofyears.Thesectionoflineintendedforreplacementin2012-13isinverypoorconditionandasurveyandsubsequentlinedesignhasbeencarriedouttoprovideoptimumpoleplacementforreplacementpoles.Thisworkisrequiredasthelineneedsreconfigurationandtheconditionissuchthatreplacementonanasrequiredbasiswouldseemuchofthelinereplacednonetheless.

Justification

Thissectionof11kVlinerequiresreplacementtoprovideareliableandsafesupplytotheMoonlightandAtarauareas.Publicandworkersafetyconsiderationsmakethisamustdoproject.


Theonly other alternative to this project is to replace individual poles on an as requiredbasis, however asmentioned,most poleswould be replaced if thiswas the case. The opportunity to reconfigure the line toprovideoptimumpolepositionsalsolendsweighttocompletingasectionoflineasopposedtoindividualpolereplacement.


41016: Kumara Junction to Kumara 11 kV Line Replacement

Costs: $80,000 Project Timeline: July 2012 - August 2012

The line fromKumara Junction through to Kumarahas beenprogressively replacedover a numberof yearswiththefinalsectionofline,intendedtoreplacetheexisting54yearoldlineinverypoorcondition,theonlysectionyettobecompleted.Negotiationswithlandownersarelookingpositiveandafinallinerouteshouldbeestablishedinearly2012.Thelineneedstobereconfiguredtooptimisepolepositionsandtheconditionissuchthatreplacementonanasrequiredbasiswouldseemuchoftheremainingsectionoflinereplacednonetheless.

Justification

Thissectionof11kVlinerequiresreplacementtoprovideareliableandsafesupplytotheKumaraarea.Publicandworkersafetyconsiderationsmakethisamustdoproject.


Theonly other alternative to this project is to replace individual poles on an as requiredbasis, however asmentioned,most poleswould be replaced if thiswas the case. The opportunity to reconfigure the line toprovideoptimumpolepositionsalsolendsweighttocompletingasectionoflineasopposedtoindividualpolereplacement.

41060: Garvey’s Creek 11 kV Line Replacement

Costs: $45,000 Project Timeline: October 2012 - November 2012

The11kVlinefromtheStateHighwaytoGarvey’sCreekminehasbeenprogressivelyreplacedoveranumberofyearswitharelativelysmallnumberofcondemnedpolesremaining.AlthoughthesepoleshavenotbeeninspectedusingthePortaSCANpoledensitymeasuringdevice,previousinspectionshavemadeitclearthattheyneedtobereplaced.

Justification

Thissectionof11kVlinerequiresreplacementtoprovideareliableandsafesupplytotheGarvey’sCreek/CraigsFlatarea.Publicandworkersafetyconsiderationsmakethisamustdoproject.


Theonlyotheralternativetothisprojectistoreplaceindividualpolesonanasrequiredbasis,howevermostpoleswouldbereplacedifthiswasthecase.Theopportunitytoreconfigurethelinetoprovideoptimumpolepositionsalsolendsweighttocompletingasectionoflineasopposedtoindividualpolereplacement.

41062: S670, Ahaura - Relocate 11 kV Line

Costs: $45,000 Project Timeline: April 2012 – May 2012

Apublicsafetyinvestigationwasinitiatedafteracontractorhadestablishedagravelpiledirectlyunderthe11kV linetraversinghisgravelyard,severelyreducingtheconductorclearance. Duringthe investigation itwasdiscoveredthatthe11kVhardwoodpolescrossingthecontractorspropertyareinpoorconditionandareinapositionwheretheycouldbedamagedduetothenatureofthecontractorsbusinessandassociatedvehiclemovements. Itwasdecided that the sectionof11kV line inquestionbe relocatedclearof thecontractorsactivities.

Justification

Toensureasafe11kVsupplythesepolesneedreplacingawayfromthecontractorsyard.



Protectivecoversorwarningflagscouldbeattachedtothelinetoprovideavisiblewarningforthecontractor,howevergiventhepoorconditionofthepolesandthattheyhavereachedreplacementcriteria, ithasbeendeemedprudenttoreplaceandrelocatetheline.

Inspection, Service & Testing

Distribution Condition Assessment



Thereareinexcessof3390woodendistributionpolesonthenetwork,whichwillrequireathoroughinspectionincludingscanningwiththerecentlyimplementedPortaSCANXBSpoledensitymeasuringdevice.

Given a five year inspection schedule, 680 wooden distribution poles will require detailed inspection andassessmentannually.Inadditiontothewoodenpoles,thereare9748concretedistributionpolesthatrequireregularinspection.Asthereisnorequirementforundergroundinspection,inspectionandassessmenttimesarefarlessthanwoodenequivalents,howeveranalysisofassessmentresultsremainssimilar.

Justification

Best practice assetmanagement calls for regular inspection and assessment of assets, therefore inspectionof distribution assets is required. The condition assessment programme allows identification of defectivecomponentsandaidsinforecastingassetlives,providingaplatformforreplacementplanning.


As the drivers for the condition assessment of distribution assets are safety and regulatory, there are noalternativeoptionsavailable.

Distribution Line Patrols


Generallydistribution linepatrolsarecarriedout toestablish thecauseofa fault,however it is intendedtoinclude11kVcriticallinesinPMschedulessimilartothatawardedtosub-transmissionlines.

Apatroldiffers fromaConditionAssessment inspectionasfarasapatrol isabriskvisit toeachstructureoraccesswayandavisualinspectionisallthatisgenerallyrequiredwithanydefectsoranomaliesrecorded.

Aswell as routine patrols, other patrols such as after extremeweather events are also carried out and aidin potential fault identification. The allocated funding allows for thePM schedules tobe carriedout and acontingencyforanyspecialpatrolsthatmayberequired.

Justification

Toensuredistributionassetsremainsafeandoperational,regularpatrolsarecritical.Resultingreportscontaininginformationsuchasdefectivecomponents,potentiallandownerissues,accessissuesandsafetyconcernscangenerallybeaddressedbeforetheybecomeaproblem.



Thepatrollingoflinesonaregularbasishasbeencarriedoutinearnestonlyrecentlyandhasalreadyprovidedinformationthatcouldhavepreventedfaultsand/orsafety issues. Toceasecarryingoutthesepatrolscouldcontravenepublicsafetyregulationsandcompromisesecurityofsupply.

11011: 11 kV Crossarm Replacements


Conditionassessmentandpatrolshaveidentifiedanumberofdistributioncrossarmsthathavedeterioratedtothepointwherereplacementisrequired.

Over600distributioncrossarmshavebeenidentifiedtobein“NeedsReplacing”orworsecondition,howeveritisplannedtocarryoutmoredetailedaerialinspectionstomoreaccuratelydeterminetheextentoftheissue.

Justification

Topreventconductordrop,allcrossarmsneedtobecapableofwithstandingtheloadsplaceduponthem,eveninthemostextremeweatherevents.Giventhis,crossarmsmustbecheckedandreplacedwhererequired.


Ascrossarmsarecriticaltotheoverallsupportofconductors,asmentioned,theymustbecapableofsupportingloadsexpectedofthem.Thereforethereisnoalternativeoptionthantoreplacedefectivecrossarms.

5.8.5.2 TwotoFiveYearPeriodProjects

Enhancement

Light Conductor Replacement (2014-2016) $50,000 p/year

Over recentyears the replacementof light conductor (Mullet,7/.064)hasbeencarriedout for twoprimaryreasons. Thefirstwastoensurethe lineswithina7kmradiusofzonesubstationscouldwithstandthefaultcurrents that theconductorcouldbesubjected towithout failing, theother reasonwas the lackof suitablespares,particularly jointingsparesfortheflatbodiedMulletACSR. Manyofthesetypesofconductorshavebeenreplaced,howeverpocketsstillremain.Althoughacontingencysumhasbeenallocatedeachyearfrom2014-2016replacementoftheseconductors,detailedanalysishasnotyetbeencarriedouttodeterminehowmuchremainsandthecosts toreplace. Inaddition,suitable jointingmethodshavebeendevelopedfor theMulletconductorwhichmayprovetobeanacceptableriskonthenetworkparticularlyininlandareas.Detailedanalysisistobeundertakeninthe2012-13yearwithascopeofworkresultingfromthesestudies.

Replacement

Nelson Creek State Farm, Re-route and Replace 11 kV Line (2013-2014) $80,000

An assessment in 2008 of hardwood poles at theNelson Creek State Farm showed that at least four polesneedreplacingwhileanumberofothersaredeemedtobeinverypoorcondition.Thisfinancialyearwillseeadesigncarriedouttoinvestigatethefeasibilityofre-routingthelinealongarecentlyformedroadtoavoidtheinhospitableterraincurrentlyencounteredbyworkers.

Park Street – Jollie Street 11 kV Overhead to Underground Conversion (2013-2014) $50,000

A public safety assessment has determined that the 11 kV overhead line, constructedwith concrete poles,traversesa schoolplayingfieldandcouldposeapotentialhazard.Tomitigate thishazardoptionsare tobeinvestigatedandconsideredinthe2012-13yearandifrequired,implementedthefollowingyear.Optionscouldincludetheconversionoftheoverheadlinetoanundergroundcircuit.


Removal of the Seaview 11 kV Line (2013-2014) $85,000

With the relocationof themainHokitika feeders fromArahura toKaniereRoad coupledwith theverypoorconditionofthe11kVlinetraversingtherearoftheSeaviewcomplex,therequirementforthissectionoflinewasassessed.Astudywascarriedoutbydesignstafftodeterminewhetherthe lineshouldberetainedandupgraded,orremovedandhaveexistinginstallationssuppliedfromthe11kVlinetraversingtheStateHighway.

The result of the study,which also considered any potential landowner/easement/access issues and designconstraints,recommendedthatitismoreefficienttoreconfigurethecustomersuppliesthatconnecttothe11kValongtheStateHighwaythanattempttorebuildtheexistinglinemainlybecauseoftheinaccessibilitytomostofthelineduetothebrokennatureofthecountryandrestrictedaccess.

Thisprojectwillseetheremovaloffifteenhardwoodpoles,whichwouldotherwiserequirereplacement,frombushcladterrainandrelocateservicestotheeasilyaccessibleStateHighway.

5.8.6 Reticulation

5.8.6.1 Twelve-Monthperiod(over$30,000)

Replacement

42013: Kaiata LV Line Relocation

Costs: $40,000 Project Timeline: June 2012 - July 2013

ArequestwasreceivedfromalandowneratKaiatawhowishestodevelophispropertyandneedstheLVlinesupplyingneighbouringpropertiesremovedasitrestrictsdevelopments.Asurveyanddesignwascarriedoutandaplanhasbeenestablishedtorelocatetheline,suppliedfromthelineattheStateHighwayasopposedtotraversingrearsections.

Justification

Toensurethelineispositionedonaroutesuitabletoallparties,witheasementsgrantedovertherouteprotectingthelineinfuturethisworkneedstobecarriedout.Accesstothelineforinspectionormaintenancewillalsobeassured.


Severalalternativerouteswereconsidered,howeverconnectingtothelineontheStateHighwaywasdeemedthemostsuitableasitisdirectandthelandowneriswillingtogranteasementsacrosshisproperty.Shouldthelineremaininit’sexistinglocation,accesscannotbeguaranteed.

42014: Reticulation Condemned Pole Replacement


Aswith thesub-transmissionpolesanddistributionpoles,manyreticulationreplacedhavebeen included inprojects that replaced sections of line deemed to be reaching replacement criteria.With the shift in AssetManagementstrategytobemoremaintenancefocused,onlyreticulationpolesthathavebeenproventohavereached theendof theiroperational lifewill be replaced. Toprove this, thorough inspection, including thescanningandanalysiswiththePortaSCANXBSpoledensityscanningsystemwillberequired.

Eightyfivereticulationpoleshavebeenidentifiedtobeinpoororworseconditionusingthetraditionaldigandprobemethodofassessment. Considerationmustbegiven toPortaSCANXBS resultswhichwillmost likelysignificantlyreducethenumberofpolesrequiringreplacementduetothemoreaccurateassessmentthatthePortaSCANXBSprovides.


Fromtimetotimeitmaybemoreprudenttoreplaceseveralpolesinasectionoflineifconsiderationssuchasre-configuration,landownerissuesoroutagerestrictionswarrantthis.

Justification





12014: Reticulation Condemned Crossarm Replacement


ConditionAssessmentandpatrolshaveidentifiedanumberofreticulationcrossarmsthathavedeterioratedtothepointwherereplacementisrequired.

590reticulationcrossarmshavebeenidentifiedtobein‘Poor’orworsecondition,howeveritisplannedtocarryoutmoredetailedaerialinspectionstomoreaccuratelydeterminetheextentoftheissue.

Justification

Topreventconductordrop,allcrossarmsneedtobecapableofwithstandingtheloadsplaceduponthem,eveninthemostextremeweatherevents.Giventhis,crossarmsmustbecheckedandreplacedwhererequired.


Ascrossarmsarecriticaltotheoverallsupportofconductors,asmentioned,theymustbecapableofsupportingloadsexpectedofthem.Thereforethereisnoalternativeoptionthantoreplacedefectivecrossarms.

Reticulation Condition Assessment



Thereareinexcessof2140woodendistributionpolesonthenetwork,whichwillrequireathoroughinspectionincludingscanningwiththerecentlyimplementedPortaSCANXBSpoledensitymeasuringdevice.

Given a five year inspection schedule, 428 wooden distribution poles will require detailed inspection andassessmentannually.Inadditiontothewoodenpoles,thereare1878concretereticulationpolesthatrequireregularinspection.Asthereisnorequirementforundergroundinspection,inspectionandassessmenttimesarefarlessthanwoodenequivalents,howeveranalysisofassessmentresultsremainssimilar.

Justification

Best practice assetmanagement calls for regular inspection and assessment of assets, therefore inspectionof reticulation assets is required. The condition assessment programme allows identification of defectivecomponentsandaidsinforecastingassetlives,providingaplatformforreplacementplanning.



Asthedriversfortheconditionassessmentofreticulationassetsaresafetyandregulatory,therearenoalternativeoptionsavailable.

43001: Condemned Service Pole Replacement


Overanumberofyearsmanyservicepoleshavebeendeemedtohavereachedreplacementcriteriaandhavebeenreplacedaccordingly.Thispracticeistocontinue,howevertheassessmentofservicepoleswillbemorethroughthan inthepast. Thenumberofservicepolesrequiringreplacementhasreducedoverthe last fewyears,hencetherelativereductioninfunding.

Justification




5.8.6.2 TwotoFive-YearsPeriodProjects

Development

Cowper Street – Develop LV Link (2013-2014) $50,000

TheconstructionofthedistributionsubstationattheHighStreetBusinessParkextendedthenetworksufficientlytoallowaLVlinkalongCowperStreetbetweentheBusinessParkandintoCowperStreet.Installingapproximately55m(x2)ofLVcable intotheexistingductsfromtheBusinessParksubstationto join intotheexistingcablealongCowperStreetwillcreatemorediverseswitchingoptionsandallowforimprovedloadsharingbetweensubstationsinthearea.

5.8.7 DistributionSubstations

5.8.7.1 TwelveMonthPeriod(over$30,000)

Development

65003: New 11 kV Connections


Aswithnewserviceconnections,new11kVconnectionsarelargelydrivenbydevelopmentinthearea.Numbersmayvary,forexample78applicationsfor11kVsupplywereprocessedin2008yetthenumberin2011reducedto38.Giventhisvariation,fundinghasbeensetatamedianleveloverthelast4years.

Justification

Westpowerprovides an11 kV connection servicewhich generally includes installationof appropriate fusing(networkconnectionpoint)andphysicalconnectiontothenetworkconnectionpoint.


Asthedriversfortheconnectingofnewservicesisbythecustomer,therearenoalternativeoptionsavailable.


68001: Purchase of New Transformers

Costs: $449,000 Project Timeline: April 2012 – March 2013

Aswithnewserviceconnectionsand11kVconnections,thepurchaseofnewtransformersarelargelydependentondevelopmentinthearea. Thepurchaseofnewtransformersfluctuatesrelativeto11kVconnections,forexample65transformerswerepurchasedin2008asopposedto31in2011.

Justification

Aswiththe11kVconnectionserviceWestpowerwillprovideatransformerandcontinuetoownandmaintainthetransformerforhose11kVconnectionsrequiringone.


As thedriver for thepurchaseof transformer is generallyby the customer, therearenoalternativeoptionsavailable.

Enhancement

55002: Increase Transformer Site Capacity (Uprate)


Asmoreanalysisisbeingcarriedoutontransformerutilizationwithinthenetwork,thenumberoftransformersreplacedwithhigherratedunitshasincreased.Thishelpstoensureanacceptablequalityofsupply.

Justification

Westpowerisobligedtodeliveraqualitypowersupplyandacorrectlyratedtransformercanassisttoensuresuchasupply isavailable. WestpowerAssetManagementprocessesallowthemonitoringofthenumberofconnectionstoatransformerandsizeaccordingly.


Asthedriversfortheconnectingof installationstotransformers isbythecustomer,therearenoalternativeoptionsavailable.

55001: Greymouth CBD Sub Upgrade (S44 Badger Lane)

Costs: $66,000 Project Timeline: May 2012 - June 2012

The Greymouth CBD Subs Upgrade project has been in progress for a number of years, refurbishing CBDsubstationsasrequired.AreportrecentlysubmittedregardingtheconditionofS44atBadgerLanesuggestedthattheLVpanelsrequiredupgradetoensureasafeenvironmentandsecuresupply.

ItisintendedtoreplacetheagingmetalcladswitchboardwithamodernequivalentcompletewithJeanMullerfuseunits.ThiswillincludereconfiguringtheLVbusandre-routingsomecablestosuit.ThisprojectwillbealogisticalchallengeassupplywillneedtobemaintainedtotheCBDatalltimes.

Justification

It is critical that the supply to the Greymouth business area is maintained to a high standard. S44 wascommissionedin1958withmuchoftheoriginalequipmentstillinservice.Thisequipmenthasreachedtheendofitsoperationallifeandneedstobeupgradedwithmodernequivalentequipment.



Astheequipmentinquestionisatanagewherereplacementisnecessary,nootheroptionsareavailable.

Replacement

45003: S1544 Otira – Upgrade LV panel

Costs: $30,000 Project Timeline: November 2012 - December 2012

S1544atOtira,aconcreteblockbuildingsubstation,housesageingLVswitchgearinpoorconditionthatneedstobereplacedwithmodernequivalents.Load intheareahasdecreaseddramaticallyoverrecentyears, thiscoupledwithKiwiRailabandoningtheswitchgearthattheypreviouslyownedandmaintainedhasresultedinanumberofredundantorunder-utilizedLVswitchingunits.

ItisintendedtooptimisetheexistingLVarrangement,replacingthe1960’sstylemetalcladswitchboardwithmodernLVpanelcompletewithJeanMullerfuseunits.Thesubstationbuildingwillalsoberefurbishedincludingpaintingandsealingtheinteriorandexterior.

Justification

Althoughasmentioned,theloadinOtirahasdeclinedoverrecentyears,areliablesupplyintheareaiscritical.Giventheremotelocation,faultresponsetimescanbelengthy,justifyinganyexpenditurewhichhelpstoreduceunplannedoutages.


Demolishingthebuildingandinstallingapadmountsubstationhasbeenconsideredhoweverthebenefitsthatthebuildingbringsforstorageoffaultsparesetc.lendsweighttomaintainingtheexistingstructure.


15006: Sub (Site) Upgrades


Distributionsubstationupgradesarecarriedoutwhenasubstationhasbeenidentifiedashavingsubstandardequipmentattachedandneedtobeboughtuptoanacceptableleveltoprovideareliableandsafesupply.Thenumberofsubupgradesisexpectedtorisewiththeinceptionofthesubinspectionprogrammewhichwillseeeverysubvisited,testedandassessedinfiveyearlycycles.

Justification

To ensure a safe and reliable supply, transformer sites on the networkmust be kept at a high standard ofmaintenance.Publicsafetyisparamount,thereforeanyworkrequiredtominimiseoreliminatepotentialhazardsfromcomponentssuchasearthdroppersmustbepromptlyattendedto.


Assafetyandreliabilityofsupplyaretheforemostdriversforsubstationupgradestherearenoalternateoptionsavailable.


15012: Distribution Sub Inspections – Testing of Earths etc

Costs: $130,000 Project Timeline: May 2012 - June 2013

In accordancewith best industry practice, all distribution substations are to be visited and inspectedon anannualbasisandthoroughlyinspectedatfiveyearcycleswhichincludeearthtestingandageneralassessmentofconditionobservedandrecorded.Ofthe2320activedistributionsubsonthenetwork,464aretobethoroughlyinspectedeachyear.

Justification

To ensure a safe and reliable supply, transformer sites on the networkmust be kept at a high standard ofmaintenance.Publicsafetyisparamount,thereforeanyworkrequiredtominimiseoreliminatepotentialhazardsfrommustbepromptlyattendedto.


Assafetyandreliabilityofsupplyaretheforemostdriversforsubstationupgradestherearenoalternateoptionsavailable.

15009: Relocate Sub Fuses for 11 kV Spurs

Costs: $50,000 Project Timeline: April 2012 – March 2013

Toassistinminimisingoutagesonmainlinefeeders,aprojectistobeinitiatedtorelocateanyHVfusesonspurlinesfromthesubstationpoletothemainlinetake-off.Thiswillensurethatanyfaultedcomponentonthespurwillonlyblowthefusesonthespurandnottripthenearestmainlineprotectiondevice.

Justification

Relocatingspurlinefusestothemainlinetake-offwillreduceoutageson11kVfeedersbyisolatingthefaultedspurline,avoidingmainlinecircuitbreakertrips.


Asreliabilityofsupplyistheforemostdriverforrelocatingfusestothemainlinetakeoffpoles,therearenoalternateoptionsavailable.

5.8.8 Services

5.8.8.1 Twelve-MonthPeriod(over$30,000)

Development

63001: New Service Connections


Newconnectionsarelargelydrivenbydevelopmentinthearea.Numbersmayvary,forexample309applicationsforsupplywereprocessedin2008yetthenumberin2011reducedto181.Giventhisvariation,fundinghasbeensetatamedianleveloverthelast4years.

Justification

Westpowerprovidesaconnectionservicewhichgenerallyincludesinstallationofappropriatefusing(networkconnectionpoint)andphysicalconnectiontothenetworkconnectionpoint.



Asthedriversfortheconnectingofnewservicesiscustomer,therearenoalternativeoptionsavailable.

5.9 Overall Work Plan

Westpowerhasapolicyofretiringolderassetsthathavereachedtheendoftheireconomiclifewherethereisnoeconomicmeansofprovidinglifeextension.Someofthetriggerswhichwouldsuggestareplacementstrategybeingemployedratherthanongoingmaintenancewouldinclude:

• Morethan50%ofalinesectionreachingreplacementcriteriawithinthefollowingfive-yearperiod;

• Technicalobsolescence;

• Healthandsafetyconcerns(e.g.SeriesIAndelectoil-filledringmainunits);

• Difficultyinobtainingspareparts;

• Inabilitytomeetcurrentneeds.

Westpoweralsoexperiencesseverecorrosioninareasneartothecoast,anditisoftenmorecost-effectivetoinstallnewcorrosion-resistantfittings,forinstance,ratherthancontinuingtorepairexistingfittings.

Thereisanaturalbusinessdrivertomaintainratherthanreplaceintheformoftaxbenefits,andthisprovidesacountervailingforcethatensuresthatareasonablebalanceismaintainedbetweenthesetwoapproaches.

5.9.1 MaintenanceTriggers

Maintenanceworkislargelybasedontheconditionoftheassets,asdescribedinSection6.

ThescopeofworkplannedundereachmaintenanceactivityisquantifiedwhereverpossibletoassistinreviewingWestpower’sachievementinthefuture.Theestimatedmaintenanceexpenditureisprojectedinthissectionandwhere relevant, theconsequencesof theproposedmaintenanceprogrammesarenoted. It shouldbenotedthat analysis ofmaintenance strategies and programmes is an ongoing process and themost cost-effectivemeansofmaintainingthesystemisconstantlyunderreview.Insomeinstances(e.g.polereplacement),furtherinvestigationandanalysisisrequiredtodetermineasuitablestrategy.

Themaintenancerequirementsareinfluencedbydevelopmentprojects,manyofwhich, iftheyproceed,willleadtodismantlinganddecommissioningofassetswhichwouldotherwiserequiresignificantrepairs.

For consistency within this plan, the baseline planned maintenance expenditure projections assume, forconsistencywithin thisplan, thatdevelopmentprojectswill takeplaceasprojected in this section. Itwillbenecessarytomonitorthelikelihoodofeachprojectproceedingclosely,andadditionalremedialworkwillneedtobeprogrammedifcertainprojectsdonotproceedoraresignificantlydelayed.

Table5.20summarisestheplannedmaintenanceprojectsandprogrammesbycategoryfortheplanningperiod.

5.9.1.1 RepairsandRefurbishment

AlllinerepairsarecarriedouttotherequirementslaiddowninWestpower’slinemaintenancestandards.ThesearebasedoninternationalpracticecombinedwithlocalknowledgeandNewZealandlegislativerequirements.

Table 5.20 - Maintenance Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 4180 4446 4468 4580 4650 4477 4648 4862 5099 5323

Faults 541 571 607 641 680 717 759 803 850 899

Repairs 302 318 335 352 371 390 411 432 457 480

Total 5023 5335 5410 5573 5701 5584 5818 6097 6406 6702


5.9.2 ReplacementTriggers

5.9.2.1 MajorRefurbishments

Itisnecessarytoretaininservicesomeolderlines,whichareinpooroverallcondition.Theselinesrequireon-goingrepairsandrefurbishment.

Majorrefurbishmentonalllinetypesisestimatedtoabsorbonlyasmallproportionofthetotalmoneyproposedtobespentonlineworkinanyyear.

5.9.2.2 WoodPolesandCrossarms

Itiscurrentlyprojectedthatapproximately200poleswillneedchangingoverthenextyearinordertocopewithdefectsarisingontheexistingwoodpolelines.

Woodpolesarebeingchangedtoconcreteortreatedsoftwoodwhereverpossible,duetotheincreasinglypoorqualityandincreasingpriceofimportedhardwoodsfromAustralia.Localsoftwoodsoftheheightandstrengthsneeded are beginning to becomemore expensive andmay require ground-line preservation techniques toextendtheirin-servicelife.

Theuseofconcretepoles,providingtheycanbesourcedattherightpricefromthelocalsupplier,canresultinsignificantsavingsinon-goingmaintenance,increasedlinereliabilityandincreasedlineworkersafety.

5.9.2.3 ConductorsandAccessories

Asapolicy,allreplacementACSRisbeingpurchasedwithagreasedcorewire.Wherecorrosionresistanceiscriticalincoastalareas,allAAACisusedforitssuperiorcorrosionresistanceproperties.

Forlargerconductorswithanaluminiumcross-sectionalareaofover95mm2,WestpowerpolicyistouseAAACexclusively.


From the condition assessment programme it is estimated that there are approximately 300 33 kV EPDMstrain insulators requiring replacementover thenextfiveyears toavoidanunnecessary riskof linedroporfaultoutages.Theseinsulatorshavebeenproventodeterioraterapidlyaftertenyears;thereforeaproactiveapproachisrequiredtomanagetheriskoffailure.

Thereplacementofsuchinsulatorsisahighprioritybecauseofitsimmediateimpactonsystemreliability,andbecauseofthesafetyriskoflinedropsiftheworkisnotattendedto.

5.9.3 Enhancement

Table5.22summarisestheplannedenhancementworksfortheplanningperiod.

Thisactivityoutlinesworkwhich isplannedtoenhancethesystem.By this, itmeansthat this increases thecapacityofthesystemto:

• Providemoreload,

• Enhancevoltageregulation,

Table 5.21 - Replacement Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Replacement 2499 1150 611 881 727 842 669 1433 1374 1029

Table 5.22 - Enhancement Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Enhancement 2111 260 246 188 228 203 543 164 223 194


• Improvesecurityandreliability.

Itincludesprojects(atspecificsites)andprogrammesofrelatedworkcoveringanumberofsites.

5.9.4 Development

Thissectionoutlinestheprojectscurrentlyanticipatedovertheplanningperiod.Thenatureofeachprojectisbrieflydescribedalongwiththereasonwhyitappearstoberequired.ThejustificationsforincludingeachoftheprojectsintheplanarecategorisedasdescribedinSection6,namely:

• Specificcustomerrequests(andcommitmenttoincurproject-relatedcharges);

• Anticipateddemandgrowth;

• Tomeetsecurityplanningguidelines;

• Economics(i.e.wheretheprojectproducesoverallcostsavings).

Table5.23summarisestheplanneddevelopmentworksfortheplanningperiod.

Table5.24outlinestheactivityandtheassettypenumbersusedfordevelopingtheprojectnumbers,whicharepresentedinthefollowingformat:year/activity/assettype/projectnumber.

Table 5.23 - Development Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Development 1437 1014 947 1095 1024 1004 1080 1209 1185 1269

Table 5.24 - Format of Project Numbers

Activity AssetType

1 IS&T 0 Sub-transmission

2 Faults 1 Distribution

3 Repairs 2 Reticulation

4 Replacement 3 Services

5 Enhancement 4 ZoneSubstations

6 Development 5 DistributionSubstations

6 MVSwitchgear

7 SCADA/Comms/Prot

8 DistributionTransformers

9 Other


5.10 Subtransmission Assets

Asdiscussed inSection3,thisassetclass involves33kVand66kVpower lines.The66kVassetsare leasedtoTranspowerandareacritical factor inthereliabilityofthenationalgrid inthearea.Accordingly,ahigherstandardofcareandmaintenanceisrequired.

Tables5.26to5.28expandontheIS&T,projectexpenditureplannedintermsofconditionassessmentprogrammesandtreetrimmingprogrammes.

Table 5.26 - Condition Assessment ($’000)

Asset Type 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Distribution 150 159 169 179 189 201 213 226 239 253

ReticulationLines 55 59 62 66 70 73 78 83 88 93

SubTransmissionLines 82 87 92 98 104 110 116 123 131 139

Total 287 305 323 343 363 384 407 432 458 485

Table 5.27 - Tree Trimming ($’000)

Asset Type 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Network 501 486 469 455 444 438 433 431 432 436

0

2000

4000

6000

8000

10000

12000

14000

16000

1 2 3 4 5 6 7 8 9 10

Year

$('

00

0)

Activity Inspection, Service & Testing Development

Replacement Faults Enhancement

Repairs

Figure5.25-ExpenditurebyActivity(incorporatingdatafromTable5.11to5.13)


5.10.1 Greymouth-Kumara66kVLine

Theageofthisassetisapproachingmidlife,requiringincreasedlevelsofinspectiontomanageriskandidentifyearlysignsofdeterioration.

5.10.1.1Maintenance

Routine Patrols and Inspections

Anaerialandgroundpatrolofthislineisperformedannually.Faultpatrolsandfaultrepairsarecarriedoutonanas-requiredbasis.

Inadditiontopatrols,adetailedinspectionoftheentirelineisregularlycarriedout.Duringthisinspection,everyaspectofthelineischeckedandrecorded.Theresultswilldeterminetheextentofmaintenancetobecarriedoutinthecomingyears.

A 100% ground-line inspection, including ultrasonic pole density analysis,was carried out in 1998 to give abaselineforfutureinspections.

Thermographicsurveysarecarriedoutonanannualbasistocheckforhotjointsthatcouldleadtolaterfailure.Thesesurveysarenormallycarriedoutattimesofhighloadsuchasthewinterperiodtoincreasethechancesofdetectingamarginaljoint.

AtreetrimmingregimehasbeenestablishedduetothehighgrowthexperiencedontheWestCoast.Thisentailsthesubtransmissionlinesbeingclearedofvegetationeverytwoyearssoastoreducetheincidenceofaccidentalcontactduringstormyconditions.

5.10.1.2Faults

Theleveloffaultoccurrenceiscloselylinkedtoconditionoftheassetandtoexternalfactorssuchasclimaticconditions.

As far as climatic conditions are concerned, lightning and windstorms are usually the greatest sources ofproblems.Thislinehasalsodevelopedtransientearthfaultsduringwetweatherafterlongdryspells,possiblysymptomaticofinsulatorcontamination,butthisisveryrare.

Itisverydifficulttopredictthenumberoffaultsfromyeartoyearduetoclimaticconditions.AnestimateforfaultworkisprovidedbasedoninformationintheMaximoAssetWorksManagementSystem(AWMS)nowusedbytheassetmanagementdivision.

5.10.1.3RepairsandRefurbishment

AlllinerepairsarecarriedouttotherequirementslaiddowninWestpower’slinemaintenancestandards.Thesearebasedoninternationalpractice,combinedwithlocalknowledgeandlegislativerequirements.

Adecisionwill bemadeonpossible insulation replacement toward themiddleof theplanningperiodoncequantitativedatahavebeengatheredontheactualconditionofthecurrentinsulators.

Table 5.28 - Sub-Transmission - Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 654 674 697 726 759 782 819 865 916 966

Faults 22 23 25 26 28 29 31 33 35 37

Repairs 32 34 36 38 40 43 45 48 51 54

Replacement 948 125 98 102 105 93 97 102 107 113

Enhancement 1800 0 0 0 0 0 0 0 0 0

Development 50 0 0 0 0 0 0 0 0 0

Total 3506 856 856 892 932 947 992 1048 1109 1170


5.10.1.4Enhancement

Asa conditionof the leaseof thisasset toTranspower,a circuit ratingof35MVAmustbemaintained.ThecurrentDogACSRconductorhasa summertimeratingslightlybelowthisvalueand re-conductoringmayberequiredinthefuture.

Notwithstandingthis,Transpowerhaveyettorequestfullratinganditisveryunlikelythatloadgrowthwithintheplanningperiodwillrequiretheextracapacity.

5.10.2 Kumara-Kawhaka66kVLine

5.10.2.1Maintenance


Faultpatrolsandfaultrepairsarecarriedoutonanas-requiredbasis.

Thisline,althoughonly13yearsold,willbeincludedintheconditionassessmentprogramme,with20%ofthelinethoroughlyinspectedannually.Thiswillbeinadditiontoatwice-yearlygroundpatrolandannualpatrol.

Alljointsusedareofthecompressiontypeandwerecarefullytestedwithamicro-ohmmeterduringinstallation.Asaresult,thermographsurveysareunlikelytobeofanybenefitthroughouttheplanningperiodandarenotplannedfor.

5.10.2.2Faults


Asfarasclimaticconditionsareconcerned,lightningisthemostlikelycauseofproblems.Inthetimethatthelinehasbeeninservice,ithasonlysustainedonetransientfault,andthiswasduringaseverelightningstorm.


Norepairsorrefurbishmentisplannedforthisline.Treeslikelytocauseaproblemwereclearedfromtheroutepriortoconstructionandwillnotimpactonthereliabilityofthelineduringthefirsthalfoftheplanningperiod.

5.10.2.4Enhancement

Withtheexceptionofthepossibleinstallationofenhancedlightningprotection,shouldthisprovenecessary,noenhancementprogrammesareplannedforthisasset.

5.10.3 NorthWestland33kVNetwork

WiththeexceptionoftheDobson-Arnoldline,allofthelinesinthisareawereconstructedsince1984,givingamaximumageofonly26years.Themedianageofthisassetgroupislessthantenyears.

TheageoftheDobson-Arnoldline(around60years)warrantshigherlevelsofinspectionandrefurbishment.Inaddressingthismatter,aprogrammehasbeenimplementedtorenewanypoleidentifiedasdefectiveoverafive-yearperiod.

5.10.3.1Maintenance




Inadditiontopatrols,adetailedinspectionofthislineistobecarriedoutonarollingfive-yearbasis,covering20%oftheroutelengthperyear.Duringtheinspection,everyaspectofthelineischecked.TheaimistoidentifyanddocumentallcomponentsthatdonotmeetWestpower’sstandards.

TheDobson-Arnoldlinehadamajorinspectioncompletedin1997whichincludedanassessmentofpoleandhardwareconditionaswellasanestimateofthepolesafetyfactorsintermsofbendingmoment.Allpoleswereshown tobeadequateat thetime;however, theageof the linemeans thatannual general inspectionswillcontinuetobecarriedout.

Allpolehardwarewillbeincludedintheinspections.

Aregularannualthermographicsurveywillbecarriedoutontheselinestomonitortheconditionofthejoints.

5.10.3.2Faults


Asfarasclimaticconditionsareconcerned,lightningandwindstormsareusuallythegreatestsourcesofproblems.

Itisverydifficulttopredictthenumberoffaultsfromyeartoyear,duetoclimaticconditions.AnestimateforfaultworkisprovidedbasedoninformationgatheredintheMaximoandGISsoftwarenowusedbytheassetmanagementgroup.


AlllinerepairsarecarriedouttotherequirementslaiddowninWestpower’slinemaintenancestandards.Thesearebasedoninternationalpracticecombinedwithlocalknowledgeandlegislativerequirements.

Withtheaboveexceptions,norepairorrefurbishmentworkisrequiredontheconcretepolelinesbecauseofthelowaverageage.

The Arnold-Dobson linewill require individual pole replacement aswell as reconductoring and reinsulationwithinthenexttenyearsunlessaplannedenhancementprojectproceeds.

5.10.3.4Replacement

IfthelevelofrefurbishmentontheArnold-Dobsonlinebecomesgreaterthan50%oftheasset,completelinereplacementmaybemorecost-effective.Thiswillbereviewedtowardtheendoftheplanningperiod.

Noreplacementisforeseeableontheconcretepolelines.

5.10.3.5Enhancement

Enhancementofanyoftheconcretepolesectionsisnotenvisagedunlessdrivenbyamajorloadincrease.Inthiscase,reconductoringisthemostlikelyactivity.

ThecapacityoftheexistingArnold-Dobsonlineissufficientforthe3MWArnoldpowerstationtoconnectintothegrid,buthasnosparecapacity.Anysignificantincreaseintheinjectiondemandatthissiteuptoapproximately5MWwillrequiretheArnold-Dobsonlinetobeupgradedbyre-conductoringandpartialpolereplacement.

5.10.4 SouthWestland33kVNetwork

MuchofthenetworkinSouthWestlandwasconstructedatthesametimeasthatinNorthWestlandandthesamecommentsapplytobothareas.

SouthWestlanddoeshavesomeuniquefeatures,withthefullyinsulatedoverheadcableroutesaroundLakesWahapoandMapourika,requiringspecialmanagement.


TheMountHercules line,withanageof34years,hasbeen refurbishedover the last fouryearsdue to thedeteriorationofpolesandconductors.ThislineprovidesanessentiallinktoSouthWestland,thusdemandingprioritywithinmaintenanceprogrammes.

WiththeadditionoftheFoxGlacier33/11kVsubstationonthenetworkin2003,the11kVlinefromFranzJoseftoFoxGlacierwasupratedto33kV.Thislinehadmajorrefurbishmentworkcarriedoutatthistimeandshouldnotneedanyfurthermajormaintenanceworkforsomeyears.

5.10.4.1Maintenance



Inadditiontopatrols,adetailedinspectionofthislineistobecarriedoutonarollingfive-yearbasis,covering20%oftheroutelengthperyear.Duringtheinspection,everyaspectofthelineischecked.TheaimistoidentifyanddocumentallcomponentsthatdonotmeetWestpower’sstandards.

Allpolehardwarewillbeincludedintheinspections.

Aregularannualthermographicsurveywillbecarriedoutontheselinestomonitortheconditionofjoints.

5.10.4.2Faults

TheleveloffaultsinthisareaissimilartothatinNorthWestland.Itmaybereasonablyargued,however,thattheincidenceofheavyrain,strongwindsandlightningisslightlyhigherthaninotherareas.


AlllinerepairsarecarriedouttotherequirementslaiddowninWestpower’slinemaintenancestandards.Thesearebasedoninternationalpracticecombinedwithlocalknowledgeandlegislativerequirements.

5.10.4.4Enhancement

AstheloadinSouthWestlandrises,itwillbenecessarytoprovidemorecapacitybetweenHarihariandWhataroatomeetthesubstantiallyincreasedloadbeingsuppliedsouthofWhataroasubstation.Themaximumacceptableloadonthiscircuitwithoutincurringexcessivevoltagedropis2.0MVA.Thisgiveslittlemarginwhensupplyingthepresenttouristseasonpeakloadof1.6MVA.Additionalreactivesupporthasbeeninstalledalongwiththeinstallationof33kVregulatorsatHarihari in2004toovercomeunacceptablevoltageregulation,particularlywhenWahapopowerstationisnotrunning.AstheloadcontinuestogrowinSouthWestland,adecisionwillneedtobemadeonwhentoincreasethesubtransmissionvoltagefrom33kVto66kV.ThelinefromArahuratoHarihariwasoriginallybuiltasa66kVlinebytheNewZealandElectricityDepartmentinthemid-1960s,andwasthenleasedtoWestpowerforoperationat33kVin1993beforefinallybeingsoldtoWestpowerin2001.Itisthereforerelativelyeasytoreliventhelineat66kVinthefuture.

Ofcourse,thiswillalsomeanthatzonesubstationsatRossandWaitahaneedtobeupgradedtorunat66kVandanew66/33kVsubstationmustbeestablishedatHarihari.

5.10.4.5Development

Nomajordevelopmentworkisplannedonthisnetworkwithintheplanningperiod.Anydevelopmentthatdoescomeaboutwillprobablybedrivenbycustomerrequirements.


5.10.5 Other33kVNetworkProjects

Table5.29summarisesthesubtransmissionprojectsforthisplanningperiod.

5.11 Distribution Assets

TheseassetscomprisethemajorityofWestpower’snetworkbydistanceandvalue.Asalogicalresultofthis,theassettypealsoaccountsforthegreatestshareofmaintenanceandenhancementexpenditure.

Table 5.29 - Sub Transmission Projects

ID Act Description 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

D Amethyst33kVConnec-tionLine 50 0 0 0 0 0 0 0 0 0

40005 RPL HKK-WTHPoleUpgrade 780 0 0 0 0 0 0 0 0 0

40010 RPL GYM-KUM66kVcctPoleReplacement 40 42 45 48 50 54 57 60 64 68

RPL Mapourika,Replacesubstandardpoles 0 0 20 21 22 24 25 27 28 30

40006 RPL ReplaceWaitangitaroaRivercrossing 43 0 0 0 0 0 0 0 0 0

40013 RPLSubtransmissioncon-demnedpolereplace-

ment30 33 33 33 33 15 15 15 15 15

40012 RPL ReplaceWaihoRiverCrossing 50 0 0 0 0 0 0 0 0 0

40011 RPL WarrensPaddock-Re-placeStructures 5 50 0 0 0 0 0 0 0 0

50002 E HKK-WTHConductorUpgrade 1800 0 0 0 0 0 0 0 0 0

10002 I ArnoldDobson33kVLinePoleReplacement 20 21 22 24 25 27 28 30 32 34

10012 IWeedSprayAccess

TracksandVariousLineRoutes

60 64 67 71 76 80 85 90 96 101

10006 IGeneralMaintenance

ofsubtransmissionlines(IS&T)

70 74 79 83 88 94 99 105 112 118

10011 IRiverProtectionWorksforSubtransmission

Lines50 53 56 60 63 67 71 75 80 84

10001 I AccessRoadMainte-nance 44 47 49 52 56 59 62 66 70 74

10004 ICoronaDischargeTestingatVariousSubtransmis-

sionLines5 5 6 6 6 7 7 8 8 8

10013 I SubtransmissionCros-sarmReplacement 25 25 25 25 25 10 10 10 10 10

10014 I AnalysisPortaSCANResults 3 3 3 4 4 4 4 5 5 5

Total 3075 417 405 427 448 441 463 491 520 547


Table5.30summarisesthedistributionprojectsandprogrammesforthisplanningperiodbycategory.

5.11.1 ReeftonArea

ThemainfeedersintheReeftonAreahavebeencompletelyreplacedoverthelasttenyears,withtheexceptionofpartsoftheReeftonTownshipandInangahuatotheIronBridge.

5.11.1.1Maintenance


The2012-13financialyearwillseethecontinuationoftheconditionassessmentprogramme.Eachline(feeder)istobeinspectedonarollingfive-yearbasis,covering20%oftheroutelengthperyear.Duringtheinspection,everyaspectofthelineischecked.


5.11.1.2Faults

FaultsintheReeftonarea,likemanyothers,aredependentonclimaticconditions.

Treeshavebeenamajorprobleminthisarea,particularlyontheGarvey’sCreekline,whichrunsthroughheavilyforestedareas,includingapineplantation.Amajortree-trimmingprojectin1998,coupledwithharvestingofmaturepinetreesinthepineplantation,hasreducedthisrisk,butitisstillconsiderable.

AfaultbasewillbemaintainedintheReeftonareacontractedtoElectroNetServicesfortheforeseeablefuturetominimisetherepairtimesthatareinvolvedduringoutage.


The condition assessment project discussed previously is likely to highlight several components requiringreplacementonthose lines.Thiswillbehandledbya livelinerefurbishmentprogramme including individualpole,crossarm,insulatorandconductorreplacementwhererequired.

5.11.2 GreymouthArea

This is the largestareawithinWestpower’sdistrictandalso involves thegreatestdiversityof line typesandconditions.

5.11.2.1Maintenance


The2012-13financialyearwillseethecontinuationoftheconditionassessmentprogramme.Eachline(feeder)istobeinspectedonarollingfive-yearbasis,covering20%oftheroutelengthperyear.Duringtheinspection,everyaspectofthelineischecked.

Table 5.30 - Distribution Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 1186 1203 1228 1232 1289 1337 1359 1414 1465 1505

Faults 324 343 364 386 409 434 460 487 516 548

Repairs 50 53 56 60 63 67 71 75 80 84

Replacement 435 325 110 110 110 110 110 110 110 110

Enhancement 0 50 50 50 0 0 0 0 0

Development 14 15 16 17 18 19 20 21 22 24

Total 2009 1989 1824 1855 1889 1967 2020 2107 2193 2271


AsfortheReeftonarea,itisexpectedthatthiswillformthebasisofarepairprogrammeinvolvingindividualcomponentreplacementsthroughouttheplanningperiod.


Aregularannualthermographsurveywillbecarriedoutonselectedhigh-densitylinestomonitortheconditionofjoints.

5.11.2.2Faults

FaultsintheGreymouthareaarenormallycausedbywindandlightning.

Treeshavebeenamajorprobleminthisarea,andaregulartree-trimmingprogrammecarriedoutatafeederlevelwillcontainthis.

ThebaseforWestpower’scontractorElectroNetServicesislocatedinGreymouth,andthiswillcontinuetoserveasafaultbaseforthearea.


PreviousinspectionprojectshavehighlightedseveralcomponentsrequiringreplacementontheNelsonCreek,Blackball,HaupiriandKoparalines.

Anon-goingprogrammetoreplaceveryoldservicepoleswillcontinueasrequired.

5.11.2.4Replacement

WithseverallineswithintheGreymouthareaandsurroundingdistrictsreachingtheendoftheireconomiclives,projectshavebeeninitiatedtoreplacetheselines.Someprojects involvethereplacementofconductor,andpoles,whileotherswillonlyseethepolesbeingreplaced.

5.11.2.5Enhancement

AsforReefton,itispossiblethatunanticipatednewindustrialloadcouldtriggertheneedtoenhancethenetwork.Notwithstandingthis,thenetworkisrelativelystrongintheGreymouthandlowerGreyValleyareas,withsupplyfrommajorsubstationsatDobsonandGreymouth,andrelativelynewfeedersemanatingfrombothsites.

5.11.2.6Development

NomajordevelopmentprojectsareplannedfortheGreymoutharea.

5.11.3 HokitikaArea

TheoverallconditionofdistributionlinesintheHokitikaisverygood,withalmostall linesconstructedusingeitherconcreteortreatedwoodpoles.

5.11.3.1Maintenance


A condition assessment programmewill be continued to identify substandard components or constructionmethods.

SimilartothatintheReeftonarea,itisexpectedthatthiswillformthebasisofarepairprogrammeinvolvingindividualcomponentreplacementsthroughouttheplanningperiod.Aftertheinitialinspection,thelineistobeinspectedonarollingfive-yearbasis,covering20%oftheroutelengthperyear.



5.11.3.2Faults

FaultsintheHokitikaareaarenormallycausedbywindandlightning,withtreesfallingthroughthelinealsobeingacommonoccurrence.

AfaultbasewillbemaintainedintheHokitikaareaandcontractedtoElectroNetServices.


Anon-goingprogrammetoreplaceveryoldservicepoleswillcontinueasrequired.

5.11.3.4Enhancement

Apartfromthespecificprojectsdiscussed,thereisnogeneralenhancementprogrammeplannedforHokitika.

5.11.3.5Development

The66/11kVHokitikasubstationprovidesastrong11kVbusneartothemajorloadsinHokitika,andthereforeremovesaneffectivevoltageconstraintthathasexistedforseveralyears.Thisallowsmajornewloadsintheareatobesuppliedwithoutsignificantdevelopmentofdistributionlineinfrastructure.

Ofcourse,anymajorloadseithersomedistancefromHokitikaorsomedistancefromtheassociateddistributionlineswillrequirenewlinedevelopment.

5.11.4 SouthWestlandArea

ThedistributionnetworkinSouthWestlandiscontainedinpocketsbasedaroundWaitaha,Harihari,WhataroaWahapo,FranzJosefGlacierandFoxGlaciersouthtoParinga,andisgenerallyingoodcondition.

5.11.4.1Maintenance

ThelinesaroundWaitaha,HarihariandWhataroahavebeensubstantiallyrebuiltoverthelasttenyearsandaregenerallyinexcellentcondition,requiringlittleplannedmaintenancework.


TheOkaritoline(fromtheWahaposubstation)isawoodpolelineconstructedinthe1970s.Althoughthislineisinreasonableconditionforitsage,itwillnowrequireahigherlevelofinspectionandservicingasitreachesmid-life.

Asforotherareas,itisexpectedthatthiswillformthebasisofarepairprogrammeinvolvingindividualcomponentreplacementsthroughouttheplanningperiod.

Thelineistobeinspectedonarollingfive-yearbasis,covering20%oftheroutelengthperyear.


5.11.4.2Faults

FaultsintheSouthWestlandareaarenormallycausedbywindandlightning.

AnotablefeatureofSouthWestland,particularlytheWhataroaarea, istheincidenceofverystrongeasterlywinds. This can, at times, result in outages as branches andother debris gets caught up in the distributionnetwork.

AfaultbasewillbemaintainedintheHarihariareaandcontractedtoElectroNetServices.


Anongoingprogrammetoreplaceveryoldservicepoleswillcontinueasrequired.


Any poles identified as reaching replacement criteria as a result of the pole inspection programmewill bereplacedasrequired,butthesearenotexpectedtocompriseasignificantnumberbecauseoftheageinvolved.

5.11.4.4Enhancement

AsmanyofthedistributionlinesintheSouthWestlandareahaverecentlybeenrebuiltorupgraded,thereisunlikelytobearequirementforcapacityenhancement.Thereisapossibilitythatsomesmallareasmayrequirethiswork,however,asaresultofin-filldevelopment.

5.11.4.5Development

Extensionofthe11kVundergroundnetworkislikelyinFranzJosefasthetownexpands.Amajornewresidentialsubdivisionprojectisunderway,butcurrentindicationsarethatitcouldbedevelopedinapiecemealfashionoverseveralyears.

Table5.31detailstheplannedexpenditureovertheAMPperiodforeachoftheabovedescribedprojects.

Table 5.31 - Distribution Projects


E LightConductorRe-placement 0 50 50 50 0 0 0 0 0

41061 RPLMawheraitiThomp-

sonsRoad,11kVPoleReplacement

25 0 0 0 0 0 0 0 0 0

41002 RPL Blackball-AtarauRd-11kVPoleReplacement 80 0 0 0 0 0 0 0 0 0

41016 RPLKumaraJunctiontoKumara-11kVLine

Replacement80 0 0 0 0 0 0 0 0 0

41061 RPLNelsonCreekStateFarm,Re-routeandReplace

11kVLine10 80 0 0 0 0 0 0 0 0

41065 RPL RemovalofSeaviewFeeder 0 85 0 0 0 0 0 0 0 0

41062 RPL S670,Ahaura-Relocate11kVLine 35 0 0 0 0 0 0 0 0 0

41060 RPL GarveysCreek11kVPoleReplacement 45 0 0 0 0 0 0 0 0 0

41063 RPLParkSt-BonarDrive11kVOverheadtoUG

Conversion10 50 0 0 0 0 0 0 0 0

41064 RPL ReplaceCondemnedDistributionPoles 150 110 110 110 110 110 110 110 110 110

11003 I PurchaseofAerialPho-tography 25 5 5 5 25 25 25 25 25 5

11001 I FitPoleCapstoSoft-woodPoles 2 2 2 0 0 0 0 0 0 0

11005 I RiverProtectionWorksforDistributionLines 66 70 74 50 53 56 60 63 67 70

11008 I DevelopNetworkStan-dards 20 20 10 0 0 0 0 0 0 0

11006 I AnalysisofNetworkComponents 10 11 11 12 13 13 14 15 16 17

11011 I 11kVCrossarmreplace-ments 50 50 50 50 50 50 25 25 15 15


5.12 Reticulation Assets

Westpower owns a diverse range of reticulation assets, ranging frombrand new underground subdivisions,throughto50-year-oldoverheadwoodpolelines.

Tables5.32and5.33summarisetheplannedexpenditureovertheAMPperiodbycategoryforthereticulationassets.

5.12.1 ReeftonArea

TheReeftonareacomprisesamixtureofrelativelynewundergroundconstructionandveryoldoverheadwoodpolelines,withverylittleinbetween.OneadvantageofthisareaisthatitiswellawayfromtheseacoastandsufferslessfromtheeffectsofcorrosionthanmostotherareaswithinWestpower.Forthisreason,theoverheadlinescanstillbeinserviceableconditionatanolderagethaninotherareas.

Table 5.32 - Reticulation Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 234 245 245 235 189 180 191 203 215 227

Faults 22 23 25 26 28 29 31 33 35 37

Repairs 20 21 22 24 25 27 28 30 32 34

Replacement 90 27 29 30 32 20 21 22 24 25

Development 0 50 0 0 0 0 0 0 0 0

Total 366 366 321 315 274 256 271 288 306 323

Table 5.33 - Reticulation Projects


12015 RPL KaiataLVLineRelocation 40 0 0 0 0 0 0 0 0 0

D CowperSt-DevelopLVLink 0 50 0 0 0 0 0 0 0 0

12005 RPL ReplaceCondemnedReticulationPoles 50 27 29 30 32 20 21 22 24 25

I Hokitika,HampdenSt-RemoveLV 0 0 0 0 0 0 0 0 0 0

12009 I PillarBoxReplacement 22 23 25 26 28 10 11 11 12 13

12008 I ReplaceLVLinks 5 5 6 6 6 7 7 8 8 8

12001 I DataCollectionofLVCircuits 25 25 25 5 0 0 0 0 0 0

12007 I Retrofitstreetlightswithindividualfusing 15 15 5 5 0 0 0 0 0 0

12014 I Replacecondemnedreticulationcrossarms 45 47 47 47 0 0 0 0 0 0

Total 202 192 137 119 66 37 39 41 44 46

Table 5.31 - Distribution Projects


11012 I AnalysisPortaSCANResults 15 16 17 18 19 20 21 23 24 25

11013 I PortaSCANXBSLease 21 21 21 26 26 26 26 26 28 28

Total 644 570 350 321 296 300 281 287 285 270


5.12.1.1Maintenance


Aswiththedistributionlines,the2012-13financialyearwillseethecontinuationoftheconditionassessmentprogramme.Eachline(feeder)istobeinspectedonarollingfive-yearbasis,covering20%oftheroutelengthperyear.Duringtheinspection,everyaspectofthelineischecked.

Asforotherareas,itisexpectedthatthiswillformthebasisofarepairprogrammeinvolvingindividualcomponentreplacementsthroughouttheplanningperiod.


5.12.1.2Faults

Faultsarelimitedtotheoccasionalsubstationfuseblowingorthefailureofapole,eitherduringhighwindsorwhenhitbyavehicle.Faultstaffintheareaareabletohandlethesefaultslocally.


Anypolesidentifiedasreachingreplacementcriteriaasaresultofthepoleinspectionprogrammewillbereplacedasrequired,andifthelevelinparticularsectionsoflineexceeds50%ofthelinevalue,thiswillbeupgradedtoareplacementprogrammeforthatsection.

Itisexpectedthatmostremedialworkwillbeaccomplishedthroughsimplecomponentreplacement.

5.12.1.4Replacement

DuetopreviousreticulationlineupgradesintheReeftonarea,replacementsarenotrequiredinthisfinancialyear.Theon-goingconditionassessmentprogrammemayidentifyreplacementsforlateryears.

5.12.1.5Enhancement

Nomajorenhancementprogrammesareplannedforthisarea.

5.12.1.6Development

TherearenosignificantdevelopmentworksplannedfortheReeftonarea.Anydevelopmentthatdoesoccurwillbeonthebasisofnewcustomerrequirements.

5.12.2 GreymouthArea

The comments that applied toReefton reticulationassets apply also toGreymouth, except that the relativeamountofveryoldwoodpolelinesisgreatlyreduced.Thereasonforthisisthemajorreplacementprogrammecompletedinthe1990sasdiscussedinSection3.3.4.1.

5.12.2.1Maintenance


AswithReefton,adetailedconditionassessmentprogrammewillbecontinued.


5.12.2.2Faults

Faultsarelimitedtotheoccasionalsubstationfuseblowingorthefailureofapole,eitherduringhighwindsorwhenhitbyavehicle.

Faultstaffintheareaareabletohandlethesefaultslocally.



Any poles identified as reaching replacement criteria as a result of the pole inspection programmewill bereplacedasrequired.Ifthelevelinparticularsectionsoflineexceeds50%ofthelinevalue,thiswillbeupgradedtoareplacementprogrammeforthatsection.


5.12.2.4Enhancement

AsmostofthereticulationintheGreymouthareahasrecentlybeenrebuilt,thereisunlikelytobearequirementforcapacityenhancement.There isapossibility thatsomesmallareasmayrequire thiswork,however,asaresultofin-filldevelopment.

5.12.2.5Development

NewsubdivisionsofteninvolvethedevelopmentofreticulationnetworksthatarehandedovertoWestpoweroncompletion.Inmostcases,thedeveloperbuildsthesetoWestpower’sstandards.

5.12.3 HokitikaArea

MostofthereticulationinHokitikahasbeenundergroundedaspartofmajorreplacementprogrammesinthe1980s.Asresult,theseassetsareinexcellentcondition.Onlyasmallnumberofpocketsofoverheadreticulationremain,andthosethatdoareconcretepolelines,alsoingoodcondition.

5.12.3.1Maintenance


Noplannedinspectionsareplannedontheundergroundreticulation.


5.12.3.2Faults

Faultsarelimitedtotheoccasionalsubstationfuseblowingorthefailureofapole,eitherduringhighwindsorhitbyavehicle.Faultstaffinthearea,areabletohandlethesefaultslocally.



5.12.3.4Enhancement

AsmostofthereticulationintheHokitikaareaisalreadyundergroundwithsignificantsparecapacity,thereisunlikelytobearequirementforcapacityenhancement.

NofurtherundergroundingworkisplannedunlesssubsidisedbythelocalDistrictCouncilortheenduser.Anexceptiontothisisthecasewhereasmallsectionofoverheadlineisreplacedinanotherwiseundergroundarea,forinstance.

5.12.3.5Development



5.12.4 SouthWestland

MostofthereticulationinthetownshipsofHarihari,FranzJosefandFoxGlacierwasundergroundedaspartofmajorreplacementprogrammesinthe1980s.Asaresult,theseassetsareinexcellentcondition.Onlyasmallnumberofpocketsofoverhead reticulation remain,and those thatdoare concretepole lines, also ingoodcondition.

5.12.4.1Maintenance


Noinspectionsareplannedontheundergroundreticulation.


5.12.4.2Faults

Faultsarelimitedtotheoccasionalsubstationfuseblowingorthefailureofapole,orwhenapillarboxishitbyavehicle.Faultstafffromthearea,areabletohandlethesefaultslocally.



5.12.4.4Enhancement

Noenhancementprojectsareplannedforthisarea,asthereisamplecapacitygenerallyavailable.

5.12.4.5Development


5.13 Services

In general, Westpower does not carry out maintenance on customer-owned service lines. These are theresponsibilityofthecustomertomaintainandtheycanuseanycompetentcontractortodoso.Thereareseveralexceptionstothisgeneralrule,however,including:

• Replacementofblownservicefusesduetofaults;

• Repairofsubstandardservicelineswherethesewereneverbroughtuptostandardpriortotransferringtothecustomer;

• ReplacementofservicepolesonthestreetwherethesewerepreviouslysharedwithTelecomandarenowsubstandard;

• Repairstonetworkconnectionequipment;

• Repairstoservicespansacrossroadreserves.

Financialcontrolproceduresmeanthatonlyapprovedworkiscarriedout,andthatthecustomerwillberequiredtopayformostworkoncustomer-ownedservicelines.


Table5.34summarisestheplannedexpenditurebycategoryforservice-relatedprojectsduringtheAMPperiod.

Theon-goingreplacementofrewireablefuseswithHRCtypesaspartofLVreplacementprojectshassignificantlyreducedthenumberofprematureservicefusefailures,whichshouldbereflectedinareducedcostoffaultwork.

Servicelinesaregenerallyownedbytheendcustomerand,assuch,arenotmaintainedbyWestpower.However,as discussed above, there are some notable exceptions to this and these create amaintenance liability forWestpower.

Table5.35liststheplannedexpenditureforserviceprojectsovertheAMPperiod.

5.14 Zone substations

Table5.36summarisestheplannedexpenditurebycategoryforzonesubstationsprojectsduringtheAMPperiod.

5.14.1 Inspections,ServicingandTesting

Westpower’s station equipment is to be routinely inspected, tested and serviced in accordance with therequirements of Westpower’s maintenance standards relevant to the actual equipment. These standardrequirements, which define the scope and frequency of work, are reflected in maintenance schedules forindividualstations.

Preventativemaintenanceplans (PMs)havebeenprepared foreachstationasset typeset toa frequencyasdeterminedbyWestpower’smaintenancestandardsforthatspecificassettype.

JobplansareattachedtoeachPMdetailingtheworkplanforthemaintenancerequired.

Table 5.35 - Service Projects ($’000)


63001 D NewServiceConnec-tions 75 80 84 89 95 100 106 113 120 127

13002 RPL ServicePoleReplace-ment 60 64 67 71 76 80 85 90 96 101

13001 I Greymouth,UpgradeUnderverandaLighting 11 12 0 0 0 0 0 0 0 0

Total 146 156 151 160 171 180 191 203 216 228

Table 5.34 - Service Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 65 69 60 64 68 72 76 81 86 91

Faults 84 89 94 100 106 112 119 126 134 142

Repairs 6 6 7 7 8 8 9 9 10 10

Development 85 90 94 99 105 110 116 123 130 137

Replacement 60 64 67 71 76 80 85 90 96 101

Total 300 318 322 341 363 382 405 429 456 481

Table 5.36 - Zone Substation Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 645 706 777 873 823 867 911 959 1007 1057

Faults 12 14 15 16 17 18 19 20 21 22

Repairs 94 99 104 109 114 120 126 132 139 146

Replacement 668 620 173 348 286 245 25 761 761 321

Enhancement 36 0 0 0 0 0 315 0 0 0

Total 1455 1439 1069 1346 1240 1250 1396 1872 1928 1546


Theintervalsvaryaccordingtotheequipmentanditslocation.Specialinspectionsandtestsarealsoincludedinmaintenanceschedulesormaybearrangedasrequired.

Workidentifiedasaresultoftheroutineinspectionsandtestsisbudgetedforasrepairsandrefurbishment.

5.14.1.1StationInspectionsandTesting

Westpower’sstationmaintenance involvesageneralmonthlystation inspection inaccordancewithspecifiedprocedures,fromwhichreportsarederived.OtherstationinspectionsincorporateannualThermovision,coronadischarge,partialdischargeinspections,fireprotectionandsecurity.

5.14.1.2Switchgear

Oil-insulatedswitchgearisregularlyinspectedandtheoilischangedasnecessarydependingontheresultsofbreakdowntests,orwhenthereareobviousvisualsignsofhighcarboncontent.Extraservicingiscarriedoutwheretheswitchgearhassustainedahigherthannormallevelof“heavy”faults.

Maleandfemalecontactsarecheckedforwear,anddressedorreplacedasnecessary.

VacuumorSF6gasinsulatedswitchgearundergoesregularvisualinspectionincludingchecksofSF6gaspressure.

Abaselineultrasonicdischarge investigationwas carriedout early in 1999 for substationswith11kV indoorswitchgear,andthishasformedthebasisforfuturestudies,whicharecarriedoutatregularintervals.

Thermovisionandpartialdischargeinspectionsarecarriedoutonallswitchgearonanannualbasis.

5.14.1.3PowerTransformerServicingandTesting

As part of Westpower’s maintenance programme, all major power transformers have an annual minormaintenanceservicewhichencompassesavisualinspection,routinediagnostictestsandminorrepairworkinaccordancewithWestpower’sstandardswhichincorporatemanufacturers’recommendationsandWestpower’sexperience.

Ingeneral,maintenanceonthetransformersconsistsofmaintainingoilwithinacceptabledielectricandaciditystandards,patchingupcorrosion,fixingoilleaksandannualdiagnostictestsontheinsulatingoil.Inaddition,theunitsfittedwithOLTCsrequireperiodicinspectionofthetapchangers,andthecontactsaredressedorreplacedasnecessary.AdditionalremedialworkrequiredoutsidethescopeofthemaintenancecontractisreferredtoWestpowerforfurtheractionandbudgetedasrepairsandrefurbishment.

5.14.1.4OilTesting-OilConductivityandDissolvedGasAnalysis

Over the last sevenyears,all zonesubstationshavehadDissolvedGasAnalysis (DGA) tests carriedout,andthesehaveidentifiedpotentialproblemsthatneedmonitoring.ThiswillbefollowedupbyfurtherannualoilconductivityandDGAtestsuntiltrendsarereliablyestablished.Oncethisisdone,theperiodwillbereviewed,possiblyonanindividualunitbasis.

Costingforminormaintenanceisverydependentonlocationandhasbeenbasedonthepresentmaintenanceexpenditure.

Costingformajormaintenance,e.g.OLTCs,isnotonlydependentonthelocationofthesitebutalsotheusageandtypesofunit.Someunitshavetobeservicedeverytwoyearsandotherseverysixyears.

5.14.1.5StructuresandBuswork

Theroutinemaintenanceofstructures,busworkanddisconnectorsisusuallyperformedsimultaneouslywhenaparticularcircuitorsectionofbusisreleasedfromservice.


Disconnectorsarescheduledforservicingeveryfouryearsbutthismaybeextendedwhenthereareoperationaldifficulties in gettingamaintenanceoutage. The servicing is non-invasiveand is generally limited to checks,adjustments,lubrication,corrosioncontrolandcleaning.

Busworkandassociatedhardwareisinspectedandmaintainedwithdisconnectors,andincludescheckingandcleaningofinsulators.Atsiteswhicharesubjecttoatmosphericpollution,insulatorcleaningmustbedonemorefrequentlythanusual.Structuresaremaintaineduptoamaximumintervaloffouryears,andworkislimitedtocorrosioncontrol,generalcheckingoffixingsandremovalofanydebris.Woodpolesaresubjecttoacheckforsignsofrotting.Ithasbeendecidedthatformoststations,earthtestingcanbecarriedouteveryfiveyears,andthiswillbecomethepracticeinfuture.

5.14.1.6InstrumentTransformers

AspartofWestpower’smaintenanceprogramme,allinstrumenttransformershaveanannualminormaintenanceservice which encompasses a visual inspection, routine diagnostic tests and minor repair work. Additionalremedialwork required is outside the scopeof themaintenance contract and is referred toWestpower foraction.

5.14.1.7OtherStationEquipment

Thenewbatterybanksarevirtuallymaintenance-free,andonlyabasicinspectionandchargercheckisnecessary.

Fireprotectionandsecurityalarmsystemsaretobeinspectedeverythreemonthsandservicedannually.Otherswitchyardequipmentsuchaslocalservicetransformers,surgediverters,cables,etc.aremaintainedasnecessarywhentheassociatedcircuitistakenoutofservice.

5.14.2 MaintenanceWorks

Thefollowingisasummaryofallmaintenanceworks(I,S&T)tobecompletedinzonesubstationsinthenext12months.Theseareallon-goingbudgetsthatarecarriedoutforthedurationoftheoverallAMPperiod.

14014: Carry Out Thermovision Inspections of Zone Substation Equipment - $7,000

To identify high resistant joints present in zone substations, a Thermovision inspection programme is to becarriedoutatallzonesubstations.Strategiclinesshallalsobeinspectedonarotationalbasis,witheachlinebeingreviewedeverythreeyears.

14015: Corona Discharge Testing at Various Zone Substations - $14,000

To identify any failing insulation in zonesubstations, a Corona Discharge inspectionprogrammeistobecarriedouteverytwoyearsat all zone substations. Strategic lines shall alsobeinspectedonarotationalbasis,witheachlinereviewedeverythreeyears.

14017: Update Zone Substation Drawings and Filing System - $25,000

Fundshavebeenallocatedtoupdatethebacklogof Station drawings and develop a new filingsystem/audittrailforallfuturedrawingupdates.

ThermovisionInspectionPhoto


14019: Oil Filter and Dry Out System for Transformers - $26,000

Anumberof thezonesubstationTransformershavemoisture ingresswhichseverely shortens their life.Theportablefilteranddryoutsystemistobemovedaroundthezonesubstationtransformerstoremovemuchofthismoistureviaonlinefiltering.

14020: Perform Oil Tests at Zone Substations (DGA) - $26,000

Anenhancedbaselineanalysisoftransformeroilconductivityanddissolvedgaseswillbecontinuedthisyeartogainabetterunderstandingoftheassets.

14024: Operator Training, Site Inductions and Site Familiarisation - $14,000

Afundhasbeenmadeavailableforoperatortraining,sitefamiliarisation,inductions,etc.atZonesubstationsandremotelocationsinthenetwork.

14027: Purchase of Portable Earths and Authorisation - $14,000

Ensureanadequatesupplyofportableearthsandpermitequipmentrequiredforoperatingtobeavailableonsite.

14029: Westpower Store – Storage of key assets in a controlled environment - $11,000

CarryoutastudythisyeartodeterminerequirementsforstoringWestpowerassetsinacontrolledenvironment.Studytoinclude–listofassetsandlocation,database,controlledprocedureforbookingin/outassets,locationofstore,indoor/outdoortemperaturecontrolledenvironment.

14031: Zone Substation – Landscaping and beautification - $14,000

Thisisanongoingprojectwhichincorporates,asthetitlesuggests,landscapingandgardeningworkaimedatimprovingtheamenityvaluesatWestpower’szonesubstationsites.

14032: Zone Substation – OLTC and Regulator maintenance - $75,000

Aplannedmaintenance/refurbishmentcyclehasbeendevelopedforallOLTCandregulatorassetstoprolongthelifeofthesecrucialassets.Fundshavebeenmadeavailablefortheongoingcostsrequiredeachyear.

14034: Zone Substation – Transformer refurbishment and maintenance - $50,000

Aplannedmaintenance/refurbishmentcyclehasbeendevelopedforallzonesubstationtransformerassetstoprolongthelifeofthesecrucialassets.Fundshavebeenmadeavailablefortheongoingcostsrequiredeachyear.

14035: Zone Substation – Building maintenance - $41,000

Thisisanongoingprojectwhichcanincludebuildingmaintenancesuchascladdingrepairs,spoutingrepairsetc.onallofWestpower’szonesubstationbuildings.

14037: Zone Substation – WMS relocation, site installation, disconnection costs - $27,000

ThisisanongoingprojectwhichincorporatesasthetitlesuggestsWMSrelocation,transportcosts,installationanddisconnection.

14040: WMS (Mobile Substation) Storage - $14,000

CoveredstorageisrequiredtoprotecttheWMSfortheperiodswhenitisnotinuse.


14041: Zone Substation Preventative Maintenance - $43,000

Four-yearlypreventitivemaintenanceplanshavebeendevelopedforsubstationdisconnectors,BUSsections,etc.toprolongthelifeofthesecrucialassets.Fundshavebeenmadeavailablefortheon-goingcostsrequiredeachyear.

5.14.3 FaultRepairs

Equipmentfailuresoccurrandomlyandwithoutwarning,andrangefromasimplecircuitbreakermechanismfailureduetoabrokencirclip,toacostlytransformerwindingfailure.Thecostbudgetedisthecosttorestoresupplyor the service following the failure,not the costof any repairworkafter supplyor servicehasbeenrestored.

It isestimated that thereareapproximately twosuch faultspermonth. It isexpected this frequencywillbereducedasaged/defectiveequipmentisrefurbishedorreplaced.

Theprojectedexpenditureisbasedonactualexpenditureincurredinrecentyears.Itisnotpracticabletoallocateprojectedexpenditureagainsteachsubstationassetcategory,giventherangeoffaultswhichcanoccur.

5.14.4 PlannedRepairsandRefurbishment

Thisareaofexpenditureincludescorrectiveworkidentifiedfollowinginspectionsandtests,andwhileundertakingroutinemaintenanceorfollowingequipmentfailures.Themagnitudeandcostsoftheworkcanvarygreatly.

Theplannedexpenditurealsoincludesthecostofmaterialsandspares.

Westpowerhasformulateditsreplacementprogrammebasedonthecriteriabelow.

5.14.4.1PowerTransformers

Themajorcausesofpowertransformerfailuresarewindingandinternalconnectionfaults.Thesearecaused,ingeneral,byelectricalcauses,e.g.throughfaultsorlightningstrikes.

Theothermajor internalmaintenanceonapowertransformer isoil refurbishmentanddesludging,which iscarriedoutasrequiredbasedonoilaciditytestresults.ItisnotexpectedthatthiswillberequiredonanyofWestpower’sunitswithintheplanningperiod.

Atmidlife,afulldry-outandcoreretightenisrecommended.

5.14.4.2RadiatorReplacement

Radiatorreplacement isonlycarriedoutoncoolerswherethedesignof theradiatorsorextentofcorrosionmeansrepairscannotbecarriedoutsatisfactorily.

Thecorrosionoccursafter20ormoreyearsofageintransformersincorrosiveenvironments(suchascoastal).The radiators are replaced only once in the life of a transformer. Only two ofWestpower’s current powertransformersmeetthiscriteria.

5.14.4.3Repainting

Paintingiscarriedoutonaregularbasisataperiodofgenerallybetween10and15years,dependingonsiteconditions.

5.14.4.4OtherEquipment

Ongoingrepairsarerequiredtoavarietyofotherstationequipmentincludingportableearthingequipmentandbatterybanks.


5.14.4.5CircuitBreakers-Outdoor

InlinewiththepracticeofoverseasutilitiesasreportedbyCIGRE,Westpowerhasapolicy,subjecttoproject-specificeconomicanalysis,ofreplacementratherthanlifeextensionofagedordeficientbulkoilandminimumoilcircuitbreakersbymajorrefurbishment.

Circuitbreakersarealsoreplacedforthefollowingreasons:

• Wheretheyhavehighmaintenancecosts;

• Wheretheyareunreliableduetoanincreaseddefectrate;

• Whereasystemnoderequiresamaintenancefreecircuitbreaker;

• Wheremaintenanceoutagescannotbetolerated.

Itisinternationallyrecognisedthat40yearsisgenerallythe“timeexpired”lifeofcircuitbreakers.Sometypeshaveaneconomiclifegreaterorlessthanthisfigure.Bulkoilbreakersgenerallyhavealongerlife,whileminimumoilbreakerstypicallylastonly30to35years.

Whileageisnotitselfcriteriaforreplacement,analysisbasedonthelikelytotaleconomiclivesforeachtype,makeandmodelofcircuitbreakerprovidesameansofassessinglikelyfuturereplacementrequirements.Thereplacementsthemselveswouldbedeterminedbysafety,economicsandreliabilityassessmentsatthetime.

5.14.4.6CircuitBreakers-Indoor

Metalclad switchgear deteriorates with age,resulting in aging of insulation materials, e.g.formationofvoidsandpenetrationofmoisture.Visible compound leaks and audible coronadischargeoftenaccompanythis.

Replacementisjustifiedprimarilyonreliability/risk of failure grounds and customer serviceoperating limitations. There is potential forexplosive failure, which occurs infrequently(approximatelyonesuchfailureeverytenyears).PreviousfailuresofSO-HImetalcladswitchgearhaveledtotheGreymouth11kVswitchboard,theonlySO-HItypeinWestpower’sarea,beingreplacedin2003.

Ascontractorsworkclosetotheequipmentandtheequipmentisoil-filled,thereisanincreasedriskofpersonalinjury.Overseasutilitieshaveadopteddesignssuchthatnewoil-filledequipmentisnotinstalledindoors,andblastwallshavebeeninstalledbetweenoldequipmentandplaceswherecontractorsarerequiredtoworkforextendedperiods.

ModernSF6/vacuumreplacementinstallationswithair-insulatedbuschambers,ratherthantheoldcompoundinsulatedtypes,andarevirtuallymaintenance-free.Thereisahighcostassociatedwithmaintenanceofoldoil-filledandcompoundinsulatedequipment,whichrequiresannualmajorserviceandfrequentfaultmaintenance.

ThetypicaleconomiclifeofWestpower’sindoormetalcladswitchgearinstallations(typically11kV)hasbeenassessedtobe50yearsbasedonpastexperience.Atpresent,onlyasmallpercentageareover20yearsold.

5.14.4.7Structures,DisconnectorsandBuswork

Westpower’spolicyofusingeithergalvanisedsteelorconcretesupportcolumnsinswitchyardsmeansthatthereisonlyminimalmaintenancerequiredforbuswork.

Figure5.37-CircuitBreaker-Indoor


Disconnectorsarescheduledforreplacementwhentheydevelopahistoryofunreliabilityorfailures,whentheirmaintenancecostsbecomeunacceptablyhigh,orwhentheyareidentifiedasbeingelectricallyunder-rated.

AprogrammeiscurrentlyunderwaytoreviewtheconditionandsuitabilityofeachdisconnectorinWestpower’snetwork.Ithasbeenfoundthattheoldertypeofdisconnectorwithoutflickerarcinghornsisnotsuitableforuseinmainlineswhenparallelingoffeedersisinvolved,althoughtheyarestillquitesuitableforuseonspurlines.Areplacementprogrammeisinplaceand,forthepurposesofthisplan,acontingencysumhasbeenallowed.

5.14.4.8InstrumentTransformers

Aged instrumenttransformersareonlyreplacedwhentheyfail,orwhentheyareaboutto failasdiagnosedby testing.Theyare thenreplacedwithasimilarunit,usuallyaspare.Other replacementsoccurduringsitedevelopmentworksand,dependingonwhethertheconditionandratingsetc.ofthetransformeraresuitableforuseatanothersite,theymaybescrapped.

AttheGreymouthsubstation,the66kVinstrumenttransformerswillbereplacedovertimewithvandal-resistantunitsusingcompositeinsulatorsbecauseoftheriskoffailureduetoongoingvandaldamage.

5.14.4.9PowerTransformers

DobsonT6andFoxT1Transformersarenearingtheendoftheirserviceablelives.AsumforbothTransformershasbeenallowedtoreplacethesein2019/20and2020/21respectively.

Therearenoplanstoreplaceanyoftheotherexistingpowertransformersduringtheplanningperiod,basedontheageandconditionoftheunits.

Thereisaconcernthatanincreasedreplacementrequirementduetodeterioratingconditionwillberequiredwithinthenext20to30years,sincethetransformerspurchasedinthe1970sarelikelytobegintofailataround50yearsofage.

Regardlessofwhetherapre-emptivereplacementprogrammeisundertaken,itseemslikelythatunitswillfailatanincreasingrateinfuture,andthiswillforcereplacement.Providedsufficientdiagnostictestsareundertakento identify imminent failure andprovided some suitable spare units are available, this should not lead to anoticeabledecreaseincustomersupplyreliability,andcouldbeacost-effectivereplacementstrategyoption.

5.14.5 MaintenanceSummary

Insummary,thezonesubstationmaintenanceexpenditureisshowninTable5.36.

Thereareconsistentexpenditurerequirementsforpowertransformerrepairwork, involvingradiatorrepairs,repainting,repairstointernalconnectionsandoilrefurbishment.

Overall,otherstationexpenditureprojectionsaresimilartopresentexpenditurelevels,withsomechangesandtrendsforspecificassetsandactivitiesresultingfromtheAMPanalysis.

5.14.6 Enhancement

TheageprofileofWestpower’szonesubstationsissuchthatonlyminimalenhancementexpenditureisrequiredthroughouttheplanninghorizon.Thecapacityofalloftheassetsissufficienttohandlenormalexpectedloadgrowthoverthenexttenyears.


Oil Interception Facilities

Oil interception facilities are installed tomeet environmental requirements under theResource Management Act. Previous policydid not set a cut-off criterion for the amountofoilatasitebeforeoilcontainmentfacilitieswereinstalled.Thishasnowbeensetat1500litresinlinewithTranspowerstandards,whichwillpossiblybethemeasureforwhatcouldbeconsidered“reasonablynecessary”intermsoftheAct.

5.14.7 Development

Alldevelopmentprojectsaredependenteitheronnewinvestmentagreementsbeingreachedwith large customers or a clear economicjustification.

TherearenodevelopmentprojectsplannedforthisAMPperiod.

Table5.39liststheexpenditureforthezonesubstationprojectsplannedforthisAMPperiod.

Figure5.38-OilInterceptionFacility

Table 5.39 - Zone Substations Projects


EWaitahaZoneSubstation-PreparesiteforWMS

access36 0 0 0 0 0 0 0 0 0

54021 E

HokitikaProtectionUpgradeDesignand

InstallationandAsBuiltDrawings

0 0 0 0 0 0 315 0 0 0

44010 RPL BatteryReplacementProgramme 19 20 21 22 23 24 25 26 26 27

44015 RPL

WahapoZoneSubsta-tion-ReplaceCombiflexRelays,ProtectionSet-

tingupgrade

108 0 0 0 0 0 0 0 0 0

RPLWahapoZoneSubstation-ReplaceCB1&Protec-

tionRelay71 0 0 0 0 0 0 0 0 0

44020 RPLRapahoeZoneSubsta-tion-33kVdisconnectorupgrade(1002structure)

0 0 26 0 0 0 0 0 0 0

44022 RPLWhataroaZoneSubsta-tion-ReplaceCB1&

protectionrelay0 90 0 0 0 0 0 0 0 0

44023 RPLRapahoeZoneSubsta-tion-Replace11kVmetalcladswitchgear

0 0 126 0 0 0 0 0 0 0

44024 RPL

ArnoldZoneSubsta-tion-ReplaceCB3&4withVipers&upgrade

protection

0 0 0 300 0 0 0 0 0 0




44025 RPLKumaraZoneSubstation-Constructanew11kV

switchroom400 360 0 0 0 0 0 0 0 0

RPLLongfordCornerreplaceregulatorwithsingle

phaseunits70 0 0 0 0 0 0 0 0 0

44028 RPLWhataroaZoneSubsta-tion-ReplaceCB1412withWVE38xtype

0 150 0 0 0 0 0 0 0 0

RPL

RossZoneSubsta-tion-ReplaceCB1&3withVipers&upgrade

protection

0 0 0 0 0 126 0 0 0 0

RPL RossZoneSubstation-T1protectionupgrade 0 0 0 0 0 95 0 0 0 0

44029 RPLWaitahaZoneSubstation-Replaceregulatorwith

singlephaseunits0 0 0 26 168 0 0 0 0 0

44030 RPLWaitahaZoneSubsta-tion-ReplaceCB1&ProtectionRelay

0 0 0 0 95 0 0 0 0 0

RPLCrondanun-ReplaceRegulatorwithnewsinglephaseunits

0 0 0 0 0 0 0 0 0

RPL FoxZoneSubstation-ReplaceT1(TX:2438) 0 0 0 0 0 0 0 0 735 0

RPL DobsonZoneSub-Re-placeT6(TX:2240) 0 0 0 0 0 0 0 735 0 0

RPLWhataroaZoneSubsta-tion-Replaceregulatorwithsinglephaseunits

0 0 0 0 0 0 0 0 0 147

RPLRossZoneSubstation-Replaceregulatorwithsinglephaseunits

0 0 0 0 0 0 0 0 0 147

IKumaraZoneSubstation66kVCBMaintenance

(3)0 0 0 90 0 0 0 0 0 0

IRapahoeSubstation-PaintGantrySteelwork

andReinsulate0 0 33 0 0 0 0 0 0 0

14014 ICarryoutThermovisionInspectionsofZoneSub-

stationEquipment7 8 8 9 9 10 10 11 11 12

14015 ICoronaDischarge

TestingatvariousZoneSubstations

14 15 16 17 18 19 20 21 22 23

14017 I UpdateZoneSubstationDrawings&FilingSystem 25 15 16 17 18 19 20 21 22 23

14019 I OilFilterandDryOutSystemforTransformers 26 27 28 29 30 32 34 36 38 40

14020 I PerformOilTestsatZoneSubstations(DGA) 26 27 28 29 30 32 34 36 38 40


5.15 Distribution Substations

Table5.40summarisestheplannedexpenditurebycategoryfordistributionsubstation-relatedprojectsduringthisAMPperiod.

5.15.1 Inspection,ServicingandTesting

AllofWestpower’sdistributionsubstationsrequireregulartestingeveryfiveyearsforsafetyreasonsinaccordancewiththeElectricityRegulations.Atthesametime,thegeneralconditionofthetransformerischeckedandanoilsampletakentomonitortheinternalstateoftheunit.



14024 IOperatorTraining,SiteInductionsandSite

Familiarisation14 15 16 17 18 19 20 21 22 23

14027 IPurchaseofPortable

EarthsandAuthorisationEquipment

8 9 10 11 12 13 14 15 16 17

14029 IWestpowerStore-Stor-ageofKeyAssetsina

ControlledEnvironment11 12 13 14 15 16 17 18 19 20

I ZoneSubstationBuildingClimateControl 0 0 0 0 0 0 0 0 0 0

14031 I ZoneSubLandscapingandBeautification 14 15 16 17 18 19 20 21 22 23

14032 I ZoneSubOLTC&Regula-torMaintenance 75 79 83 87 91 96 100 105 110 115

14034 IZoneSubstationTrans-formerRefurbishmentandMaintenance

50 53 56 59 62 65 68 72 76 80

14035 I ZoneSubstationBuildingMaintenance 41 43 46 48 51 54 57 60 63 66

14037 IWMSRelocation,SiteInstallation/Disconnec-

tionCosts,etc27 28 29 30 31 32 34 35 36 38

14040 I WMS(MobileSubsta-tion)Storage 14 15 16 17 18 19 20 21 22 23

14041 I SubstationPreventitiveMaintenance 43 46 49 52 55 58 61 65 69 72

Total 1099 1027 636 891 762 748 869 1319 1347 936

Table 5.40 - Distribution Substation Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 750 778 792 770 814 485 512 543 577 613

Faults 17 18 19 20 21 23 24 26 27 29

Repairs 10 11 11 12 13 13 14 15 16 17

Replacement 30 0 0 0 0 0 0 0 0 0

Enhancement 101 37 39 42 44 47 50 53 56 59

Development 90 95 101 107 114 120 127 136 144 152

Total 998 939 962 951 1006 688 727 773 820 870


Table5.41liststheexpenditureforthedistributionsubstationprojectsplannedforthisAMPperiodasdescribedabove.

5.15.2 FaultRepairs

Lightningdamageandingressofwatercausesmosttransformerfaults.

Overthelasteightyears,westpowerhashadaprogrammeofretrofittinglightningarrestorsonallsubstationsthatdonotyethavethesefitted,andthisisnowcompleted.Pastexperiencehasshownthatlightningarrestorsgreatlyreducetheriskoftransformerdamage.

Regular inspection of transformers will also reduce the number of failures due to water ingress caused bydeterioratione.g.rustytanks.

Minorrepairssuchasbushingreplacementscanbecarriedoutonsiteifnecessary,butmostfaultrepairsinvolvetheswappingofatransformerunitwithasparefromthestore.


Corrosionandresultingwatercontaminationoftheinsulatingoilindistributiontransformersisamajorconcern.Aprogrammeofidentifyingbadlycorrodedtransformertankshasbeeninstigated.

Onceidentified,thesetransformerswillberemovedforrepair,retankingorreplacementasdictatedbythestateandageoftheunit.

Majorrewindsoftransformersarenotundertakenunlessthetransformer’ssizeisover50kVAandthetransformerislessthantenyearsold.Thisisbasedoneconomics.

Table 5.41 - Distribution Substation Projects ($’000)


65003 D New11kVConnections 65 69 73 77 82 87 92 98 104 110

65002 D NewTransformerSites 25 26 28 30 32 33 35 38 40 42

55002 E IncreaseTransformerSiteCapacity(Uprate) 35 37 39 42 44 47 50 53 56 59

55001 E GreymouthCBDSubsUpgrade(BadgerLane) 66 0 0 0 0 0 0 0 0 0

45003 RPL S1544Otira-UpgradeLVpanel 30 0 0 0 0 0 0 0 0 0

15006 I Sub(Site)Upgrades 348 369 391 414 439 100 106 112 119 126

15003 I ReplacementofLiveLineTaps 10 10 10 10 10 3 3 3 4 4

15002 IHokitika-RemovePilotConductorfromSubs

andPillarBoxes5 15 15 0 0 0 0 0 0 0

15004 I Installationofearthstir-rupstodropoutfuses 5 5 6 6 6 0 0 0 0 0

15012 IDistributionSubInspec-tions-Testingofsub

earthsetc130 138 146 155 164 174 184 195 207 220

15007 IUpgradeS634TudorSt-newpadandreconfig-

ureLV20 0 0 0 0 0 0 0 0 0

15008 I InstallJanitzaMDI’s 27 27 0 0 0 0 0 0 0

15009 I RelocateSubfusesfor11kVspurs 50 50 50 0 0 0 0 0 0 0

Total 816 746 758 734 777 444 470 499 530 561


5.15.3.1OilRefurbishment/Desludging

Oilrefurbishmentisplannedfortendistributiontransformersperyear.

5.15.4 ReplacementProgrammes

Thereisamajorprogrammeinplaceforreplacingoldertransformersthathavefailedasaresultofoldageorlightning damage. The transformer technician individually assesses each transformerwhen returned to thestore,andanappropriaterecommendationonreplacementorrepairismadebytheengineer.

Thisisameansofprudentlymanagingtheassetandensuringthatanappropriateageprofileismaintained.Adistribution transformer conditionmonitoringprogramme is about to be introduced,whichwill identify theconditionofthecurrentpopulationandprovidesasubstantialbasisforassessinglikelycostsinfutureAMPs.

Current levelsof transformerreplacementsareplannedtocontinue.Typicalprices fornewunits range from$3,000forsmallsingle-phaseunitsto$20,000forurbanpad-mounttransformers.

5.16 MV Switchgear

Table5.42summarisestheplannedexpenditurebycategoryforMVswitchgear-relatedprojectsduringthisAMPperiod.

5.16.1 Inspection,ServicingandTesting

Circuitbreakersaresubjectedtominorand/ormajormaintenanceroutinesinaccordancewiththerequirementsofWestpower’s maintenance standards. Fault maintenance is also carried out when a circuit breaker hascompletedaspecifiednumberoffaulttrippings.

Modernvacuumcircuitbreakersaresubjectedtominorservicesandconditionmonitoringtestsatfour-yearlyintervalsonly.Invasivemajorservicesarenotscheduledandwouldbecarriedoutonlyifrequiredasindicatedbyconditionmonitoringtests.

Aswithpowertransformers,therearetwolevelsofservicing:

• Minorservicing,involvingexternalservicing(non-invasive);

• Majorservicing,whichinvolvesinvasiveservicing.

Belowisalistofallmaintenanceworks(IS&T)tobecompletedforMVswitchgearinthenext12months.TheseareallongoingbudgetsthatarecarriedoutyearlyforthedurationoftheAMPperiod.

16002: Disconnector Maintenance and Operation Check Programme - $95,000

Reliableandsafeoperationofdisconnectorsisimperativeduringswitching.Somedisconnectorsbecomedifficulttooperate(e.g.padlockseizesup).Afive-yearlymaintenanceprogrammeisinplacetomaintainandtest-operateeachofthe400plusdisconnectors.

Table 5.42 - MV Switchgear Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 186 193 173 181 192 203 216 228 241 253

Faults 6 6 7 7 8 8 8 9 10 10

Repairs 44 47 50 52 56 59 63 66 70 74

Replacement 123 39 42 105 48 50 53 133 61 64

Enhancement 119 78 82 40 43 45 47 50 52 54

Development 344 97 60 148 68 72 76 168 85 89

Total 822 460 414 533 415 437 463 654 519 544


16003: Recloser Maintenance – Protection, batteries, etc. - $32,000

Network reclosers require regularprotectiontestsand reclosermaintenanceasdeterminedbyWestpower’sstandards to ensure reliable and safe operation.Ongoing funds have beenmade available to complete thismaintenance.

16004: Perform Partial Discharge Tests on Network Switchgear - $14,000

Carryoutpartialdischargetestsonselectednetworkswitchgear.Thisisanongoingprojecttoassistintheearlydetectionoffaults.

Table5.43liststheexpenditurefortheMVswitchgearprojectsplannedforthisAMPperiodasdescribedabove.

Table 5.43 - MV Switchgear Projects ($’000)


DAmethyst33kVCon-

nection-InterconnectorStructureandProtection

200 0 0 0 0 0 0 0 0 0

46002 RPL

ReplaceFaultyActua-tors-(EntecloadbreakswitchorHydraulic

actuator)

45 0 0 0 0 0 0 0 0 0

46003 RPL DisconnectorReplace-ments 32 33 35 38 40 42 45 48 51 54

46004 RPL RemotelocationsBatteryReplacement 6 6 7 7 8 8 8 9 10 10

RPL RingMainUnitReplace-ment(FoxHotel) 40 0 0 60 0 0 0 76 0 0

56004 EDistributionIntelligentFaultIsolationSystem-

Study/Design2 2 2 2 3 3 3 4 4 4

56008 E Fusingofspurlinesbyfeederclassification 40 42 44 0 0 0 0 0 0 0

E InstallAutomationtoVariousDisconnections 71 34 36 38 40 42 44 46 48 50

E FitEarthFaultIndicators 6 0 0 0 0 0 0 0 0 0

D Newmainlinereclosersites(Dilmans) 25 0 0 84 0 0 0 88 0 0

D NewSpurLineReclosersonvariousSpurLines 40 14 15 16 17 18 19 20 21 22

66005 D AutomateCapacitorsatvariouslocations 42 44 0 0 0 0 0 0 0 0

66007 D NewDisconnectors 27 29 31 33 35 37 39 41 44 46

66008 D NewgangedDDOfuseunitlocations 10 10 14 15 16 17 18 19 20 21

I UpgradeEarthingatDis-connectorLocations 0 0 0 0 0 0 0 0 0 0

16002 IDisconnectormainte-nance,OperationCheck

Program95 100 78 82 87 92 98 103 109 114

IRemotelocationsmain-tenance-Protection,

Batteries,etc32 33 35 38 40 42 45 48 51 54

16004 IPerformpartialdis-

chargetestsonNetworkSwitchgear

14 15 15 16 17 18 19 20 21 22

Total 727 362 312 429 303 319 338 522 379 397


5.16.2 FaultRepairs

5.16.2.1CircuitBreakers

Faultrepairstoswitchgeararecarriedoutasrequired,butasthepopulationofolderbulk-oiltypereclosersdiminishes in line with Westpower’s circuit breakerreplacement programme, the occurrence of thesefaultshasbeengreatlyreduced.

Failures in indoorswitchgeararealso relatively rare.With the planned upgrade of the indoor metalcladswitchgear at Rapahoe and Kumara in the not toodistant future, all ofWestpower’s indoor switchgearwillbeofayoungage,and isexpectedtoprovideareliableandsafeoperationforthisplanningperiod.

5.16.2.2Disconnectors

Disconnectorsnormallyfailduetodeteriorationoftheoperatingarmswithcorrosionorfromanarcdevelopingacrosstwoormorephases.Byidentifyingunder-rateddisconnectorsandreplacingthese,theincidenceofarcingfaultsshouldbereduced.Thepreventativemaintenanceprogrammefordisconnectorsisworkingverywellatidentifyingmostpotentialproblemsbeforetheyoccur.


5.16.3.1CircuitBreakers

Plannedrepairworkinrespecttocircuitbreakerswouldincludeadditionalcorrectiveworkandrefurbishmentidentified during routine services, inspections and tests or following failures. Refurbishment work plannedincludesoverhaulofdecommissionedcircuitbreakers,identifiedassparespriortoplacingtheminstorage.


WestpowerhasdetermineditsreplacementprogrammeforHVswitchgearbasedonthefollowingcriteria:

• Safety-Whereequipmentpresentsahigherthannormalrisktopersonnelduringoperatingormaintainingtheequipmente.g.generictypesofagedbulkoilcircuitbreakerswithhistoryoffailures;Circuitbreakersthatrequirehandclosing.

• Technical suitability - This applies to equipment that is no longer suitable for its service application e.g.Disconnectorsandcircuitbreakersthatareunreliableorinconsistentinperformingtheirfunctionsduetoexcessivelywornmechanisms,equipmentwhichfailstomeetWestpower’sseismicrequirementsorUnder-ratedequipment.

• Economics-Thisiswherereplacementisjustifiedpurelyforeconomicreasons,e.g.equipmentisexcessivelyexpensive tomaintainor repair, thehigh costof sparesorwhere spares canno longerbepurchasedormaintenance-intensiveequipmentinstalledatasensitivesupplylocation.

5.16.4.1CircuitBreakers-Outdoor

InlinewiththepracticeofoverseasutilitiesasreportedbyCIGRE,Westpowerhasapolicy,subjecttoproject-specific economic analysis, of replacement rather than life extension of aged and/or deficient bulk oil andminimumoilcircuitbreakersbymajorrefurbishment.Circuitbreakersarealsoreplacedforthefollowingreasons:

• Wheretheyhavehighmaintenancecosts;

• Wheretheyareunreliableduetoanincreaseddefectrate;

Fig5.44-CircuitBreakers


• Where a system node requires amaintenance-free circuit breaker e.g.maintenance outages cannot betolerated.

Itisinternationallyrecognisedthat40yearsisgenerallythe“timeexpired”lifeofcircuitbreakers.Sometypeshaveaneconomiclifegreaterorlessthanthisfigure.Bulkoilbreakersgenerallyhavealongerlife,whileminimumoilbreakerstypicallylastonly30-35years.

While age is not itself criteria for replacement, analysis based on likely total economic lives for each type,makeandmodelofcircuitbreakerprovidesameansofassessinglikelyfuturereplacementrequirements.Thereplacementsthemselveswouldbedeterminedbysafety,economicsandreliabilityassessmentsatthetime.

Manyoftheexistingolderbulkoilreclosershavebeenreplacedwithmodernlow-maintenancevacuumcircuitbreakers.

Thecontinuingreplacementprogrammeforoutdoorcircuitbreakershasresulted intherebeingnobreakersover25yearsofage.

5.16.4.2AndelectUnits

Westpower has experienced two serious failures of Series Iversions of these oil switch units during routine operation, andtheyareconsideredtoconstituteaserioushealthandsafetyrisk.Areplacementprogrammewasinstitutedfiveyearsagotograduallyreplaceall theseunitswithnewSF6RMUtype.Atpresent, thereare no series 1 type oil switch units in the network.Westpowerstill has series 2 type oil filled Andelect switch units,which havebeen assessed as safe to operate. There are three of these unitsremaining,withnoimmediateplansforreplacement.

5.16.5 Enhancements

Several automated disconnections/sectionalisers (used to isolatefaults on rural lines) are reaching the end of their economiclife and are becoming unreliable. This results in prolonged andmorewidespread power outages than are necessary during faultconditions.

It is no longer possible to source replacement parts formany oftheseunits,andthemaintenancecostshaveincreasedsignificantly.

Areplacementprogrammehasbeeninplaceforthelasttwoyearsandisplannedtobecompletedthisyear.

Figure5.45-RingMainUnit


5.16.6 Development

Reclosers are pole-mounted circuit breakers, which automaticallyisolate a faulted section of the line from the rest of the network(Figure5.35).Wherealargeradialnetworkexists,reclosersareoftenfittedonspur lines toprevent themain line fromtrippingoutduetoa spur line fault. Theadditionofextra reclosers to thenetworkimprovessystemreliabilityandfaultselectivity.Justificationofeachprojectiscarriedoutonacase-by-casebasis.

SupplytotheWestCoast ingeneral isvoltage-constrainedandthisis partly due to the long inductive transmission lines.Whena lineoutageoccursduetofaultsorplannedmaintenanceevents,voltagecollapsecanoccurunlesssignificantsupport isavailable from localgeneration;this,inturn,maydependonwateravailability.

Amethyst Hydro is planned to be completed this year, which willimprovereliabilityofsupplyandtheabilitytocarryoutmaintenanceintheSouthWestlandarea.

VoltagesupportutilisingcapacitorsontheWestpowernetworkhashadvaried success.Atnight,when the load is low, capacitorsmaynotberequired,butarerequiredatpeak loadtimes.Astudy is tobecarriedoutthisyeartofindacost-effectivesolutiontoautomatetheswitching inandoutofexistingcapacitorbanksas required toprovidethisvoltagesupport.

5.17 SCADA, Communications and Protection

Table5.47summarisestheplannedexpenditurebycategoryforSCADA,commsandprotectionrelatedprojectsduringthisAMPperiod.

5.17.1 PeriodicInspections,ServicingandTesting

5.17.1.1SCADASystem

Theintegrityofthemainhardwareandsoftwaresystematthecontrolroomisofthehighest importancetotheongoingmanagementandsafetyof thegridnetwork.Westpower’sassetmanagementstaffmanagethecomputersystemandmaintaintheoperationalstateofthesoftwareandhardwaresystems.Thisisa24-hourtask,withstaffoncall ifrequiredtoensurehighavailabilityofequipment.Themaincomputerhardwareandsoftwareareprotectedbyamaintenancecontractwiththesupplier.

AnapprovedcontractorwillmanageallcommunicationandSCADAequipmentexternaltothecomputersystem.Thisprovidesforcontinuousmaintenanceandfastresponseforfaultrepairs.

Figure5.46-RemoteControlledDisconnector

Table 5.47- SCADA and Comms Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 360 387 383 380 390 417 423 418 432 443

Faults 45 46 48 49 51 52 54 55 57 59

Repairs 45 46 48 49 51 52 54 55 57 59

Replacement 60 35 92 115 70 244 278 215 215 295

Enhancement 55 95 75 56 141 111 131 61 115 81

Development 405 191 172 189 152 82 104 86 88 108

Total 970 800 818 838 855 958 1044 890 964 1045


5.17.1.2Communications

Everyassetistobeinspectedsix-monthlyandservicedonanannualbasis.Thesix-monthlyinspectionis,asfaraspossible,non-intrusive.Noadjustmentsaremadeuntilitemsareoutoftoleranceorperformanceisaffected.

Antennasupportstructures,e.g.woodpoles,towersandmonopoles,areinspectedeverytwoorthreeyears.

AntennaearetobecheckedannuallywithaSpectrumAnalyser.

5.17.1.3Protection

Thepolicyinthisareaistomaintainprotectionschemeswithalternatemajorandminorserviceseverytwoyearsoneachcircuit.

It should be noted that “maintenance” on protection equipment is essentially “recalibration/testing” ratherthantheconventionalviewofmaintenance,whichwouldimplyreplacementofconsumableparts.Protectionmaintenanceismainlyrequiredtoreaffirmthattheprotectioniscalibratedwithintoleranceandwilloperatewhencalledupontodoso.

Thereareinternationaltrendstowardsreducedmaintenance.Typically,intervalsarebeingincreasedtobetweenthreeandfouryearsinotherutilitiescomparabletoWestpower,particularlywheremicroprocessor(numerical)protectionsystemsareused.Theseprotectionshavein-builtself-testingandmonitoringroutineswhichreducethenecessityformanuallydrivenmaintenancetesting.

Anewfully-automatedprotectionrelaytestsetisbeingintroducedtofacilitatemaintenancetesting.Thiswillbeusedforcommissioningofnewprotection(developmentsandenhancements)aswellasmaintenance.



Westpowermaintainscommunicationsassetsatapproximately28basesites,83pole-toporRMUsitesandon10repeatersites.Theplannedrepairandrefurbishmentestimatesarebasedonpastexpenditure.

Contractmaintenancetechniciansareexpectedtorespondtoapproximately12majorfaultsperannum.

5.17.2.2Protection

Theprotectionexpenditureplannedoverthereviewperiodismainlyinthefollowingareas:

• Replacementofoutdoorjunctionboxes;

• Replacementofagedfeederprotectionandcontrols;

• Replacementoflead-acidbatterieswithsealedcells;

• Seismicstrengtheningofprotectionpanels;

• Seismicrestraintsforbatteries;

• InstallationofDirectCurrent(DC)monitoringanddistributionpanels.



Communicationsequipmenthas,ingeneral,ashorterlifeexpectancythanheavyelectricalequipment.Typicallyelectronicequipmentreachestechnicalobsolescencein5-10yearsalthoughtheequipmentcan,ingeneral,besupportedinservicefor10-15years.


5.17.3.2SCADA

Aswithall computer-based systems, it isexpected that severalupgradesof theoperating system, software-applicationsandhardwarewillberequiredthroughouttheplanningperiod.

TheSCADAmastersystemneedstobekeptuptodatewithsoftwarechangestoenablethesystemtohavemaximumfunctionalityandtoextendthelifeofthecurrentsystem.

5.17.4 MaintenanceSummary

Table5.20atthebeginningofthissectionsummarisesexpectedsystemmaintenanceexpenditure.

5.17.5 Enhancement

ThereareseveralsmallupgradejobsplannedfortheSCADA,communicationandprotectionsystemsthroughouttheplanningperiod.

5.17.5.1RemoteControlledDisconnectors

Withtheadventofindustry-wideperformancemonitoring,WestpowerisnowbeingbenchmarkedagainstotherELBsintermsofsystemreliabilityandcontinuityofsupply.Furthermore,customersarebecomingmoreawareoffaultoutages,partlyduetotheincreaseinthenumberofelectronichomeappliancesandtheresultingrelianceonacontinualsupplyofelectricity.Forthesereasons,itisbecomingincreasinglyimportanttocutdownonfaultrestorationtimes.

Onewaytodothisisbyautomatingremoteairbreakswitches.Thisgreatlyreducesthetravellingtimerequiredforafaultworkerduringsectionalisingoffaultedlinesections.Thisalsomeansthatfewerstaffarerequiredtoisolatethefault,reducingtheoverallcostoffaultrestoration.

Table 5.48 - SCADA and Communications Projects


67037 D Amethyst33kVConnec-tion-Communications 100 0 0 0 0 0 0 0 0 0

D ALDCommsUpgrade 0 0 0 40 0 0 0 0 0 0

67026 D BlueSpurRepeaterSiteDevelopment 30 20 0 0 0 0 0 0 0 0

D MtBonar,UpgradeRepeaterSite 0 0 80 50 50 0 0 0 0 0

D MtKakawau 0 0 0 0 20 0 0 0 0 0

67036 D Commstonew11kVswitchroomKumara 40 0 0 0 0 0 0 0 0 0

67013 DPaparoaProposalto

moveallaerialtosingletower

15 10 0 0 0 0 0 0 0 0

67009 D Whataroacommunica-tions 30 20 0 0 0 0 0 0 0 0

67018 D MeteringReading 10 10 10 10 11 11 11 11 11 11

67019 D VMWareServerConfigu-ration/Equipment 10 10 11 12 13 13 14 15 16 16

67011 D SCADAOffSiteBackup 5 5 5 5 5 5 5 5 5 5

67017 D 61850Rollout 10 11 11 12 13 13 14 15 16 16

67012 DSouthWestland,IP

ExpansionVHFDigitalRadio

70 40 0 0 0 0 0 0 0 0




67014 DFastIPCommstoAllReclosersitesforDIFIS

Project20 20 20 20 20 20 20 20 20 20

67031 D

CommstoMVSwitch-gearDisconnectorAutomation&NewReclosers

30 20 20 40 20 20 40 20 20 40

67033 D CommstoAutomateCapacitors 15 15 15 0 0 0 0 0 0 0

67034 D CommstoRMU’s 20 10 0 0 0 0 0 0 0 0

E AtaruIPSwitch 0 0 0 0 0 0 0 0 0 8

57003 E MtBonarRepearer 4 4 4 5 5 5 5 5 6 6

E FibreLinktoGreymouthDepot 0 0 0 0 0 0 0 0 50 0

E ChapelStIPSwitch 0 0 0 0 0 0 0 0 0 8

E CommsModificationfornew66kVbay 0 0 0 0 0 0 20 0 0 0

E HKKProtectionupgrade 0 0 0 0 0 0 50 0 0 0

E RapahoeCommsUp-grade 0 0 20 0 0 0 0 0 0 0

E CommstoupgradedRossZoneSub 0 0 0 0 0 50 0 0 0 0

E WahapoCommsUp-grade 0 40 0 0 0 0 0 0 0 0

57001 E ModificationofLoadControlSytem 10 10 10 10 12 12 12 12 13 13

57022 E SCADAMasterStationEnhancement 10 10 10 10 12 12 12 12 13 13

57025 E ICCPFeed 10 10 10 10 10 10 10 10 10 10

E WaitahaDevelopment 0 0 0 0 40 0 0 0 0 0

E CommstoupgradedWaitahaZoneSub 0 0 0 0 40 0 0 0 0 0

57011 E SCADACriticalSpares 15 15 15 15 15 15 15 15 15 15

57012 E IPFireWall/Security/RemoteSecureaccess 6 6 6 6 7 7 7 7 8 8

RPL PAP-ALDRadioLink 0 0 0 20 0 0 0 0 0 0

RPL APA-ATUmicrotikhoriz 0 0 0 0 15 0 0 0 0 0

RPL AtaruSEL2411 0 0 0 0 0 0 0 0 0 5

RPL PAP-ATUmicrotikvert 0 0 0 0 15 0 0 0 0 0

RPL PAP-ATURadioLink 0 0 0 0 0 0 0 0 0 80

RPL BlackwaterRadioLinks 0 0 0 0 0 0 0 0 0 30

RPL RlackwaterRouter 0 0 0 0 0 0 0 0 0 10

RPL RlackwaterCommsProcessor 0 0 0 0 0 0 0 0 0 20

RPL PAP-CHAPELmicrotikhoriz 0 0 0 0 10 0 0 0 0 0

RPL PAP-CHAPELmicrotikvert 0 0 0 0 10 0 0 0 0 0

RPL Dobsoncommunicationsprocessor 0 0 0 0 0 0 0 25 0 0




RPL PAP-DOBSONRadio 0 0 0 0 0 0 0 70 0 0

RPL PAP-DOBSONFibreCable 0 0 0 0 0 0 0 20 0 0

RPL T6replacement 0 0 0 0 0 0 0 20 0 0

RPL T1replacement 0 0 0 0 0 0 0 0 20 0

RPL CommsProcessor 0 0 0 0 0 0 0 0 20 0

RPL GlobeSubstationcom-municationsprocessor 0 0 0 0 0 0 20 0 0 0

RPL RFN-GLBRadioLink 0 0 0 0 0 20 0 0 0 0

RPL GreymouthsubCom-msprocessor 0 0 0 0 0 0 0 0 0 20

RPL GreymouthsubRouterandSwitches 0 0 0 0 0 0 0 0 0 20

RPLWestpowerControltoGreymouthSubstation

FibreLink0 0 0 40 0 0 0 0 0 0

RPL HKK-PAPRadioLink 0 0 0 0 0 0 70 0 0 0

RPL LandingHilltoIGHRadioLink 0 0 0 0 0 0 0 0 0 70

RPL PAP-KumaraRadioLink 0 0 0 0 0 0 0 0 70 0

47018 RPL Longfordcornerregula-torreplacement 25 0 0 0 0 0 0 0 0 0

RPL IPSwitch 0 0 0 0 0 6 0 0 0 0

RPL PAP-NGHradiolink 0 0 0 0 0 20 0 0 0 0

RPL AllanBradleyPLC 0 0 0 0 0 8 0 0 0 0

RPL PikeSubstationIPSwitch 0 0 0 0 0 0 0 0 0 10

RPL SEL2032 0 0 0 0 0 0 0 0 0 20

RPL RapahoeIPSwitch 0 0 7 0 0 0 0 0 0 0

RPL RapahoeRadioLink 0 0 20 0 0 0 0 0 25 0

RPL ReeftonSubstationIPSwitch 0 0 0 0 0 0 8 0 0 0

RPL RFNBCLtoRFNSubRadioLink 0 0 0 0 0 0 50 0 0 0

RPL SEL2032s 0 0 0 0 0 0 20 0 0 0

RPL ReeftonVoiceRepeater 0 0 40 0 0 0 0 0 0 0

RPL Rosscommunicationsprocessor 0 0 0 0 0 30 0 0 0 0

RPL SCADAMasterStationReplacement 0 0 0 0 10 150 100 70 50 0

RPL GYMCHAPELdepotmicrotikhorz 0 0 0 15 0 0 0 0 0 0

RPL GYMCHAPELdepotmicrotikvert 0 0 0 15 0 0 0 0 0 0

RPL RippleMasterInjector 0 0 0 0 0 0 0 0 20 0

47010 RPL ReplacePLC/RTUUnits 10 15 15 15 0 0 0 0 0 0

47016 RPLCommstoMVSwitch-gearReplacement

Program25 20 10 10 10 10 10 10 10 10

Total 520 321 339 360 363 437 513 362 418 484


5.18 Distribution Transformers

The population of distribution transformers covers a diverse range of sizes, types and ages. As such, it isimportantthatacomprehensivemanagementplanisputinplace,astheconditionoftheassetisnotalwayseasilydiscernibleonanoverallbasis.

Westpower’s policy is to extend the life of distribution transformerswhere this is economically feasible. Insupportofthispolicy,manydistributiontransformersrunwellbelowtheirratedvaluesformuchofthetime,resultinginlonglivesforthecoresandwindings.Providedthatthetanksandoilarewellmaintained,theoverallunitmaybekeptinserviceforupto55years.Inthisway,themaximumreturncanbeleveragedfromthesehighvalueassets.

Table5.49summarisestheplannedexpenditurebycategoryfordistributiontransformer-relatedprojectsduringthisAMPperiod.

5.18.1 Maintenance

5.18.1.1RoutinePatrolsandInspections

Smallerpole-mounteddistributiontransformersareregularlyinspectedonarollingfive-yearbasisinconjunctionwithWestpower’ssubstationearthtestingprogramme.

Theinspectionincludeschecksfor:

• Tankcorrosion,

• Paintchips,

• Breakdown,

• Oilleaks,

• Insulatordamage,

• Breathercondition,

• Terminationfaults.

Wherepossible,theoillevelischeckedandrecorded,andifanoilsamplevalveisavailable(standardissueonallnewtransformers),asampleoftheoilistakenandcheckedfordielectricbreakdown.

Largerpole-mountandallpad-mountunitshaveMaximumDemand Indicators (MDIs)whichare readeveryquarter.Theseindicateloadingtrendstobemonitoredandallowforearlyinterventionshouldaunitbecomeoverloaded.

VerylargetransformersinareassuchastheCBDsofGreymouthandHokitikahaveannualthermographsurveyscarriedouttocheckthetankandterminationtemperatures,aswellastoidentifyanyotherpotentialhotspots.Anyindicationssuggestingthatthetransformerrequiresattentionresultsinprompton-siterepairs;ifthisisnotpossible,thetransformerisswappedwithaspareunitfromthestoreandsentbacktothecontractor’sworkshopforrefurbishment.

Table 5.49 - Distribution Transformers Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 95 101 107 113 120 127 134 143 152 160

Faults 3 3 3 4 4 4 4 5 5 5

Development 449 476 504 535 567 601 637 675 716 759

Total 547 580 614 652 691 732 775 823 873 924


5.18.1.2Faults

Themajorityof faultsarecausedby lightningdamage; it isvery rare foraunit to failbecauseofoldageordeteriorationbecauseoftheregularinspectionandservicingcarriedout.

Mostfaultsarehandledbyswappingthetransformerwithaspareandsendingthedamagedunitbacktothetransformerworkshopforinspectionandrepair,orscrappingifthedamageistoosevere.

Anexceptiontothisisbushingfaultsonlargeunits,wherethebushingcanbeeasilyrepairedorreplacedon-site.


Repairscanrangefromaminorpainttouch-uponearlierpaintedunitsthroughto insulatorrepairsandboltreplacements.Refurbishmentmayincludeoilchanges,rewindsandeventankreplacements.

Rewinds are only attempted on relatively modern units where modular replacement windings are readilyavailable.

Tanksareoftensubjecttocorrosion,especiallyinthecaseofolderpaintedunits.Atthesametime,however,theinternalcoreandwindingsmaybeinexcellentcondition.Forthisreason,tanksareoftenrepairedorreplacediftheunitisotherwiseingoodcondition.

Eachunitisassessedonitsage,conditionandservicehistoryindeterminingwhethertorepairorreplacetheunit.

5.18.1.4Replacement

AllreplacementunitsarepurchasedtoWestpower’spurchasingspecifications,whichprescribegalvanisedtanks,stainlesssteelfixingsandoilsamplingvalvestominimisethecostoffuturemaintenance.

5.18.1.5Enhancement

Littleenhancementworkiscarriedoutondistributiontransformers,astheseareessentiallyastandardmodulewithnocapacityforupgrading.Occasionally,duplexarcinghornsmaybefittedtoexistingunitswherelightningarrestorscannotbeused.

5.18.1.6Development

NewunitsarepurchasedtoWestpower’spurchasingspecificationsasrequired.IndependentcontractorsinstallingnewsubstationsforcustomersmayprovidenewunitsandhandthemovertoWestpoweroncommissioning,providedthattestresultsaresatisfactory.

Table5.50liststheexpenditureforthedistributiontransformerprojectsplannedforthisAMPperiodasdescribedabove.

5.19 Other

Westpower’s four ripple injection plants are all of the samemake (Enermet SFU-K series),making lifecyclemanagementeasiertoimplement.

Laterthisyear,wewillbeinstallingastand-alonerippleplantattheWahapozonesubstation.ThiswillbeinstalledintheexistingshedandwillbeusedonoccasiontoprovideripplecontroltotheSouthWestlandareawhenWahapogenerationisrunningislandedfromtheremainderofWestpower’snetwork.

Table 5.50 - Distribution Transfomers Projects ($’000)


68001 D Purchaseofnewtrans-formers 449 476 504 535 567 601 637 675 716 759


ThisplantwillconsistofthebestavailablepartsfromthedecommissionedPlesseyTRseries75kVAplantsatReefton,GreymouthandHokitika.

Table5.51summarisestheplannedexpenditurebycategoryforthe“Other”relatedprojectsduringthisAMPperiod.

5.19.1 Maintenance

5.19.1.1RoutinePatrolsandInspections

Monthlychecksarecarriedoutaspartofregularzonesubstationvisits,whichincludethevisualinspectionsofthe:

• Converters,

• Couplingtransformers,

• Couplingcells,

• GPStimebasereceivers.

Everythreeyears,independentexpertsdetermineinjectionlevels,currentbalance,optimumtuningandloadsharingwithotherunitsduringafullinspection.

5.19.1.2Faults

Thesolidstateconstructionoftheinjectionplantsandthefactthattheyoperatewellbelowtheirmaximumpowerlevelsmeansthatfaultsareveryuncommon.

Onrareoccasions,thehigh-poweroutputtransistorsmayrequirereplacementorthelogicboardmayrequirerepair.Atothertimes,verminmaygetintotheHVcouplingcells,causingflashover.

The redundancybuilt into the injectionnetworkmeans that the failureof any singleplantwill not severelyimpactonoverallripplesignalpropagation,andfaultsareabletobehandledwithoutunduetimepressureonrestoration.


Minor repairsare requiredon thecouplingequipmentandconverters fromtimetotimeasa resultof faultevents.

Thereisnoplannedrepairandrefurbishmentprogrammeplannedforthisequipment,whichisrelativelyyoungandingoodcondition.Itisexpectedthattheplantswillgiveatleasttenyearsoftrouble-freeservice.

5.19.2 Replacement

ReplacementofalloftheoriginalTRseriesunitsisplannedoverthenextthreeyears.

5.19.3 Enhancement

Thecapacityoftheexistingequipmentisfixedandprovidesampleroomfornetworkexpansion.Noenhancementworkisplanned.

Table 5.51 - Other Projects and Programmes ($’000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

IS&T 5 5 6 6 6 7 7 8 8 8

Faults 6 6 7 7 8 8 9 9 10 10

Replacement 1 1 1 1 1 1 1 2 2 2

Total 12 12 14 14 15 16 17 19 20 20


5.19.4 Development

Nonewrippleplants(exceptWahapo,whichhasalreadybeenbudgetedfor)areexpectedtoberequiredfortheforeseeablefuture;however,allowancehasbeenmadeforunspecifieddevelopmentprojectsthatultimatelyturnupandrequireinclusionwithintheAMP.

AfullsummaryoftheexpenditurebyactivityandassettypeisavailableinSection7-FinancialSummary.


6.0 ASSET LIFECYCLE MANAGEMENT

6.1 Introduction

ThissectiondescribestheprocessesusedbyWestpowertomanagethelifecycleofitsassetsfromdesignandplanningthroughtodisposal.Atypicallifecycleofanyassetconsistsofthefollowingstages:

• Designandplanning,

• Acquisitionandinstallation,

• Maintenanceandoperation,

• Disposal.

Themaindriversforlifecyclemanagementare:

• Reliability/securityandqualityofsupplytomeetcustomerlevelsofserviceandcontractualobligations;

• Occupationalhealthandsafety toestablishasafeworkingenvironmentandcomplywithOSH legislativesafetyrequirements;

• Regulatorytomeetregulationsimposedbyexternalorganisations;

• Environmentaltocomplywithemissionregulationstoair,landandwater;

• Assetperformance/conditionuseofhistoricaldatatoassestheperformanceandconditionoftheassetsandpredictpotentialremaininglife;

• Costefficiencytoensurethatmaximumcostefficiencyisachievedinaccordancewithassetmanagementpolicy;

• CorporateimagetoensurethatanyactivitycarriedoutbytheAssetManagementteamandsubcontractorswillnotdamageWestpower’simage.

DetailsofprojectedoperatingexpenditureareincludedinSection5undertheappropriateassettype.Inthisway,thereadercanreadilyseethetotalprojectedcostsforeachassettype,alongwiththeOPEXandCAPEXbreakdown.

6.2 Maintenance and Operation

6.2.1 ReplacementvsMaintenanceTrigger

Westpowerhasapolicyofretiringolderassetsthathavereachedtheendoftheireconomiclifewherethereisnoeconomicmeansofprovidinglifeextension.Someofthetriggersthatwouldsuggestareplacementstrategybeemployedratherthanongoingmaintenancewouldinclude:

• Morethan50%ofalinesectionreachingreplacementcriteriawithinthefollowingfive-yearperiodwhenotherworkhastobecarriedoutonthatline;

• Technicalobsolescence;

• Healthandsafetyconcerns(e.g.oldoil-filledringmainunits);

• Difficultyinobtainingspareparts;

• Inabilitytomeetcurrentneeds.

Westpoweralsoexperiencesseverecorrosioninareasneartotheseacoast,anditisoftenmorecosteffectivetoinstallnewcorrosionresistantfittingsratherthancontinuingtorepairexistingfittings.

Thereisanaturalbusinessdrivertomaintainratherthanreplaceintheformoftaxbenefits,andthisprovidesacountervailingforcewhichensuresthatareasonablebalanceismaintainedbetweenthesetwoapproaches.

TheMaintenancetriggersareoutlinedinTable6.1.

ASSETLIFECYCLEMANAGEMENT 219

6.2.2 Maintenance

Maintenanceworkislargelybasedontheconditionoftheassets,asoutlinedinSection5.

ThescopeofworkplannedundereachmaintenanceactivityisquantifiedwhereverpossibletoassistinreviewingWestpower’sachievementinfutureyears.Theestimatedmaintenanceexpenditureisprojectedinthissectionand,where relevant, theconsequencesof theproposedmaintenanceprogrammesarenoted. It shouldalsobenotedthatanalysisofmaintenancestrategiesandprogrammesisanongoingprocess,andthemostcost-effectivemeansofmaintainingthesystemisconstantlyunderreview.Insomeinstances(e.g.polereplacement),furtherinvestigationandanalysisarerequiredtodetermineasuitablestrategy.

Themaintenancerequirementsareinfluencedbydevelopmentprojects,manyofwhich, iftheyproceed,willleadtodismantlinganddecommissioningofassetswhichwouldotherwiserequiresignificantrepairs.

The base-line planned maintenance expenditure projections assume, for consistency within this plan, thatdevelopmentprojectstakeplaceasprojectedinthissection.Itwillbenecessarytomonitorcloselythelikelihoodofeachprojectproceeding,andadditionalremedialworkwillneedtobeprogrammedifcertainprojectsdonotproceedoraresignificantlydelayed.

Table 6.1 - Maintenance Triggers by Asset Category

Asset Category Components Maintenance Trigger

Zonesubstations

Fences&enclosures MonthlychecksmadeoffenceswithZoneSubchecks,breakagestoberepaired.Maintenancefitterstomonitorcorrosionatgroundofgalvanisedsupporttypes.

BuildingsLandscaping.Exteriorofbuildingstobekepttidy,especiallygardensandlawn.

Foamsandwichtypebuildingstobewashedonanannualbasis.Itemsnotedthatneedrepairtohaveservicerequestraised.

Transformers AnnualDGAOilsampling.Monthlyzonesubchecks,includingBuchholzinspection,insulatorintegrity,nooilleaks,etc.

11kV&33kVswitchgear Monthlycheckofgaspressure,insulatorintegrity,etc.Maintenanceinlinewithmanufacturersmanual.

Instrumentation CheckcalibrationwithCBreleaseasabove,particularlytransducerinputstoSCADA.

Sub-transmissionlines&cables

Poles,arms,stays&bolts Evidenceofpolemovement.Evidenceofdecay/splittingoftimber.Evidenceoflightningdamage.

Pins,insulators&binders Evidenceofpincorrosion-rusting/neckingofthepins.Visiblyloosebinder.Visiblychippedorbrokeninsulators.

Conductor Evidenceof“birdsnesting”followingstrand/sbreaking.Electricalloadincreasingbeyondconductorcapacity.

LVlines&cables

Poles,arms,stays&bolts Evidenceofrot.Loosebolts,movingstays.Displacedarms.

Pins,insulators&binders Obviouslyloosepins.Visiblychippedorbrokeninsulators.Visiblyloosebinder.

Conductor Visiblycorroded,splayingorbrokenconductor.

Distributionsub-stations

Poles,arms&bolts Evidenceofdry-rot.Loosebolts,movingstays.Displacedarms.

Enclosures Visiblerust.Crackedorbrokenmasonryorfibreglass.

Transformer Excessiveoilacidity(500kVAorgreater).Visiblesignsofoilleaks.Excessivemois-tureinbreather.Visiblychippedorbrokenbushings.

Switches&fuses Coronadischargemonitoringannually.

Distributionlines&cables

Poles,arms,stays&bolts Evidenceofdry-rot.Loosebolts,movingstays.Displacedarms.

Pins,insulators&binders Evidenceofpincorrosion-rusting/neckingofthepins.Visiblychippedorbrokeninsulators.

Conductor Evidenceof“birdsnesting”followingstrand/sbreaking.Evidenceofvibration-fitdamper.

Ground-mountedswitches Evidenceofpincorrosion-rusting/neckingofthepins.LongrodtypeschalkingifEPDMtype.

11kVSwitchgear Coronadischargemonitoringannually.


Repairs and Refurbishment

AlllinerepairsarecarriedouttotherequirementslaiddowninWestpower’slinemaintenancestandards.ThesearebasedoninternationalpracticecombinedwithlocalknowledgeandNewZealandlegislativerequirements.

6.2.2.1 Maintenance


Aerialandgroundpatrolsofsubtransmissionlinesareperformedannually.Faultpatrolsandfaultrepairsarecarriedoutonanasrequiredbasis.

Thermographicsurveysarecarriedoutonanannualbasistocheckforhotjointsthatcouldleadtolaterfailure.

Thesesurveysarenormallycarriedoutattimesofhighloadsuchasthewinterperiodtoincreasethechancesofdetectingamarginaljoint.

Atree-trimmingregimehasbeenestablishedduetothehighgrowthexperiencedontheWestCoast.

Table6.2,showspatrolandinspectionfrequencies.

6.2.3 Replacements

Major Refurbishments

Itisnecessarytoretaininservicesomeolderlines,whichareinpooroverallcondition,andtheselinesrequireongoingrepairsandrefurbishment.

Majorrefurbishmentonalllinetypesisestimatedtoabsorbonlyasmallproportionofthetotalmoneyproposedtobespentonlineworkinanyyear.

Wood Poles and Crossarms

Itiscurrentlyprojectedthatapproximately 250poleswouldneedchanging overthenextyearinordertocopewithdefectsarisingontheexistingwoodpolelines.

Woodpolesarebeingchangedtoconcretepoleswhereverpossible,duetothe increasingpriceof importedhardwoodsfromAustralia.

Theuse of concrete poles leads to significant savings in ongoingmaintenance, increased line reliability andincreasedlineworkersafety.

WestpowernowspecifiesPurpleHearthardwoodforallcrossarmsthatareusedonitsnetwork,andtheseareexpectedtohavealongservicelife.

Table 6.2 - Routine Patrol and Inspection Frequencies

Voltage RoutinePatrol ConditionAssess-ment

ThermographicSur-vey

Corona Discharge-Survey *Vegetation Survey

33kV+ 6monthly 5yearly 2yearly 2yearly 2-5yearly

11kV asrequired 5yearly asrequired - 2-5yearly

400V asrequired 5yearly - - 2-5yearly

33kVHendrixCable Monthly 5yearly - 12monthly Monthly

*Note:Vegetationsurveydependantonenvironmentalfactors.


Conductors and Accessories

Asapolicy,allreplacementACSRisbeingpurchasedwithagreasedcorewire.Wherecorrosionresistanceiscriticalincoastalareas,AAACisusedforitssuperiorcorrosionresistanceproperties.

Forlargerconductorswithanaluminiumcross-sectionalareaofover95mm2,WestpowerpolicyistouseAAACexclusively.

Insulators and Insulator Fittings

Earlierconcernsabout theconditionofanumberofEPDM33kVstrain insulatorshave largelyprovedtobeunfounded,andsoaplannedreplacementfortheseunitsisnolongerscheduled.

With theexceptionof a numberof glass insulatorson the SouthWestland33 kV line,which aredue tobereplacedaspartofthelineupgrade,allotherinsulatorsandfittingsaregenerallyingoodcondition.

6.2.4 RectifyingWestpowerAssets

Networkdefectdatacapturedinthefieldareincorporatedintothegeneralworkplanviarelevantprocesses.Althoughtheprimaryfocusoftheconditionassessmentprogrammeisthemonitoringofpoleandspanassets,allassettypesaretobeincludedinthenearfuture,witheachawardedequalconsideration.

Dependingonthepriorityoftheidentifieddefect,workcouldbecarriedoutimmediatelytorectifytheproblem;alternatively,thejobcouldbescheduledtobeundertakenatamoresuitabletime.

The statusof theworkordergenerated indicates the job’s completion, fromwhich regularauditsensureallfollow-upadministrationtasksarecompleted.

All assetdataare returnedwithanupdated “ConditionCode”. Theseare separatedandanalysed for actionwhereneeded.Belowisalistoftheconditioncodesandthecorrespondingactionthattakesplace:

Excellent: Nofurtheractionisrequiredontheseassets.

Good: Theseassetshavemorethantenyears,lifeexpectancyandwillbeassessedagainwithinthisterm.

Fair: Theseassetshavelessthantenyears,lifeexpectancyandwillbeassessedagainwithinthisterm.

Poor: Thisassetcouldlastuptofiveyears,however,itisinpoorconditionandfutureassessmentwillberequired.

Needs replacing:Anyassetswiththiscodearegroupedintoareasalongwithanyotherurgentworkrequired.Aworkorderisraisedfortheasset(s)tobereplacedassoonaspossible.

Red-tagged:Allred-taggedassetsareurgentlyinneedofareplacementandbecauseofthis,workordersareraisedindividuallyfortheseassetsforpromptaction.

Aswell as condition codes, a “work required” table isutilised todriveanymaintenanceor replacements toassets.Theworkrequiredtableissplitintotwocategories,“urgent”and“non-urgent”.

• Urgent work:isgroupedintogeographicalareas.AworkorderisthengeneratedforthisareaincludinganyassetsmarkedasNeedsReplacingorRedTaggedinthe“condition”attributeintheassetdata.Anyassetthatrequiresinstantactionwillhaveaseparateworkorderraisedinordertorectifythisissueassoonaspossible.

• Non-urgent work: isalsogroupedintoareasand,dependingonthesituation,aworkorderwillberaisedstraightawayortheworkissetasideforactionduringplannedoutagesorwhentimeallows.

6.3 Disposal

Decommissionedequipmentormaterialsareonlydisposedofwhentheyarenotrequiredascriticalsparesandthereisalowlikelihoodofthembeingrequiredinthefuture.


Wheretheequipmentinvolvespotentiallyhazardousmaterials,thisisclearlystatedandtherecipientisrequiredtoprovidedocumentaryevidencethatanyfurtherdisposaliscarriedoutinanapprovedmanner.

Alldecisions totransferordisposeoffixedassetsmustbeauthorisedbytheGeneralManager–AssetsandEngineeringServices.TheGeneralManager–AssetsandEngineeringServicessignsaDisposal/TransferAuthorityRequest(DTAR)form.

Following authorisation, the appropriate networkmanager is responsible for the reallocation/disposal of allequipment.

ThesemanagersareresponsibleformaintainingaregisterofWestpowerassetsthatareavailablefordisposalortransfer.Thisinformationisusedtoenabletheeffectivereallocationofplantandequipmentwithinthenetwork.Importantly,this informationalsoenablesWestpowertoassessopportunitiestodefercapitalexpenditurebyreallocatingassetsbetweensites.

6.4 Major Maintenance Projects

6.4.1 ProjectName:GYM–KUM66kVcctPoleReplacement

ProjectCode: 40010

EstimatedCost: $685,000

StartDate: April2010

CompletionDate: March2021

The 23 km 66 kV subtransmission line from theGreymouthSubstation toTrustpower’sKumaraPowerStation(Figure6.1)wasbuilt in1977tocoincidewiththecommissioningoftheGreymouthSubstation.

OwnedbyWestpower,thelineisleasedtoTranspowerand,alongwiththe66kVcircuitfromDobson,providesn-1securitytothegreaterGreymoutharea.

The line was constructed using de-sapped, untreatedhardwoodpoles,mostofwhichare inagenerally faircondition,however,aprogressivereplacementplanhasbeen initiatedtoavoid large-scale failure.Aroundhalfofthepoleswerefittedwithaheatshrinkbandageinthe1990sand injectedwithafungicidalemulsiontheeffectivenessofthisprocessisunknown.

The pole replacement programme allows for thereplacement of six to tenpoles per annum.Althoughcondition is a major factor when determining whichpolesaretobereplaced,theconditionofmostofthepoles is similar, so other drivers may be considered.Landownerissuesorfactorssuchaspolestabilitymaydeterminewhichpolesarereplaced,

ThestandardWestpowersubtransmission17m12kNpre-stressedconcreteI-beampolearmlessconstructionisemployedformostofthereplacements,withporcelainstand-offinsulators;however,pi-polesmayberequiredfromtimetotime.ItwasintendedtoreplacetheexistingDogACSRconductorprogressivelybeginningin2012,withahighercapacityconductortoensurethelinewascapableofcarryinga35MWload.However,thisistobereconsideredintheupcomingyear,withtheoriginaldriversnolongerapparent.


Anearthwireisinstalledtheentirelengthofthelineandwillremainaspolesarereplaced.

Approximately16%of the total numberofpoleson the linehavebeenreplacedtodate.

CompletionoftheprojectisexpectedinMarch2022.

Justification:

Theestimatedlifeofwoodpolelinesis45yearsaccordingtoWestpower’s asset management policies and this coincideswiththesamenumberusedintheODVhandbook.Therefore,thelinewillreachtheendofitsscheduledeconomiclifein2022;however,anumberofpolesarealreadyreachingreplacementcriteria.

Althoughthepolesareinreasonablecondition,toavoidmassfailure of poles on the line at the end of their serviceablelife, the line needs gradual replacement. This approachwillminimiseoutagetimesandallowcoststobeapportionedovermany years. As this line is leased to Transpower tooperateaspartofthenationalgridandamainsupplyintothegreaterGreymouthandsurroundingareas,itisimperativethatahigherlevelofreliabilitybemaintainedatalltimes.

AlternativeOptionsConsidered:

Alternativesolutionswereconsideredincluding:

• Replaceentirelinewhenreplacementcriteriaarereached;

• Ongoingbasicmaintenance;replaceonfailure.

Other options such as distributed generation demand sidemanagementandadditionalvoltagesupportarenotapplicableinthiscase,astheissueisoneofreliabilitywiththelinesupplyingthemainhuboftheWestCoast.

Forreasonsdiscussedearlier,itwasdecidedthatreplacingtheentirelineoverafewyearswasnotprudentduetocostsandtheriskofblackoutsshouldthelinebeoutofserviceforextendedperiodsthatcoincidewithafailureofthenortherncircuit.

Figure6.3-showsonexistingpole

Figure6.4-showsthenewconfiguration


Ongoingbasicmaintenancewouldresultinsuboptimaloutcomes,asanincreasingnumberofcomponentswouldbegintoapproachfailurecriteriaandtheoverallcostofsuchapiecemealapproachwouldresultinasignificantlyincreasedfinalcostalongsideconsiderablyreducedreliability.

AstagedreplacementwasconsideredtobethemosteffectivemeansofmaintainingareliablesupplyofelectricitytotheGreymouthareaatthelowestoveralleconomiccost.

6.4.2 ProjectName:Replacecondemneddistributionpoles

ProjectCode: 11004

EstimatedCost: $2,962,000(overplanningperiod)



ManyofWestpower’slinesbuilt inthe1960sthroughtothelate1980swereconstructedutilisinghardwoodpoles,manyofwhichhadbeenpreviouslyused.Withtheexpectedlifeofahardwoodpoletobearound45years,dependingon thesurroundingenvironment,manyof thesepoleswill require replacementwithin theplanningperiod.Theconditionassessmentprogrammeistheprimarytoolusedtoidentifythosepolesneedingurgentreplacementandastheconditionassessmentprogrammehas intensified,so,too,hasthenumberof

polesidentifiedtobein“RedTagged”condition.

AsthegraphinFigure6.5indicates,manyofthe11kVhardwoodpolesfoundonthenetworkhavereached,orarereaching,therecognisedreplacementage.Acontingencysumhasbeensetasideforreplacementofsuchpoles,withmanybeingreplacedaspartofanentirelinesegment,whileothersinurgentneedofreplacementwillbereplacedindividuallyunderOPEX.Thesepolesarenormallyreplacedduringplannedoutagesoremployinglivelinetechniqueswherepossible.

Figure6.5-11kVHardwoodpolesAgeDistribution

2% 4%3%

9%

9%

15%

25%

8%

17%

8%

0-5 6-10 11-15 16-20 21-25

26-30 31-35 36-40 40+ UNKNOWN


Individual11kVpolereplacementhasbeencarriedoutforanumberofyearsandtherateofsuchreplacementisexpectedtoincreaseintheupcomingyears.Theemphasisonpolereplacementhasshiftedfromthatofcapitalworks,whereanumberofpolesinalinewouldbereplaced,toamoretargetedprogramme,whichwillresultinincreasedindividualpolereplacementexpenditure.

Justification:

Westpower is veryproactive in identifyingand rectifyingdefectivepoleswithin thenetwork. In adhering torelevantregulations,Westpowermustensurethesepolesarereplacedinatimelymanner.Ifadefectivepoleisnotincludedinacapitalreplacementproject,itistobereplacedundermaintenanceworks.ThecondemneddistributionpolereplacementprogrammeisjustifiedthoughWestpower’sobligationtoprovideareliablepowersupplyandadheretoregulationsandactssuchastheHealthandSafetyinEmployment(HSE)act1992.

Alternativeoptionsconsidered:

Thecondemneddistributionpolereplacementprogrammehasnoeffectivealternativesthatmeetthehealthandsafetyandregulatorydriversasdiscussed,andthereforenoalternateoptionshavebeenconsidered.

6.4.3 ProjectName:Distributionsubstationupgrades

ProjectCode: 15006

EstimatedCost: $3,663,000(overplanningperiod)



Due to the inherent dangers a substandard distribution substationmay pose, funds have been allocated toensuretheconditionofthesesitesarekeptuptoasuitablelevel.AlldistributionsubstationsontheWestpowernetwork are fitted with lightning arrestors, approved drop-out fuses and an earthing system installed to astandardapprovedbyWestpowerandwhichmeetallregulatoryrequirements.ToavoidpotentialEPRissuesandtoensureasafereliablesupplyisprovidedfromadistributionsubstation,frequentearthtestsarecarriedout and replacement of substation components are undertakenwhere required. Although theprobabilisticapproachtodistributionearthingasdiscussed in theEEAearthingguidewillbeadoptedbyWestpowerandthependingcommissioningoftheGroundFaultNeutraliser(GFN)willmitigatedangersposedbyinadequateearthingofdistributionsubstationsintheGreymoutharea,all2300distributionsubstationsonthenetworkwillneedtoremainingoodcondition.

The last fewyearshaveseenapushtohave9kV lightningarrestors replacedwith12kVunits,primarilyonsubstationsemanatingfromtheReeftonandGreymouthzonesubstationfeeders.ThiswasduetotheinstallationofaNERunitinReeftonandtheGFNinGreymouthwhichnecessitated12kVarrestorsbeinstalled.Astheseareashavebeencompleted,distributionsubsinotherareaswillbeinspectedfirstandupgradedifrequired.

Justification:

Asmentioned,Westpowerintendstoadoptaprobabilisticapproachtodistributionsubstationearthing,whichwillseeahigherdegreeofpreventivemeasurestomitigatepotentialEPRproblemsinareasfrequentedbythepublicsuchasschools,parksandmeetingplaces.Thisdoesnot,however,absolveWestpowerofitsresponsibilitytoensurealldistributionsubstationsare safeand reliable.With this inmind, theupgradeprogrammemustcontinuetoguaranteethattheseobligationsaremet.



As suitable earthing, lightning arrestors, HV and LV fuses are all essential components on a distributiontransformersite,whichareallpronetoenvironmentallyinduceddegradation,noalternativeoptionshavebeenconsidered.WhiletheGFNinGreymouthand,toalesserextent,theNERinReeftonhaveeasedtheemphasispreviously placed on the earthing system impedance of distribution substations in those areas,maintainingeffectiveearthingsystemswillcontinuetobeafocusforthecompany.

6.4.4 ProjectName:Conditionassessment

ProjectCode: N/A

EstimatedCost: $141,000(perannum)



Westpower’sassetmanagementpracticeshaveevolvedoverthelastfiveyears,ashastheconditionassessmentprogramme. Initially, the condition assessment of lines was introduced as a sporadic inspection withoutprovidingadetailedreflectionoftheconditionofeachasset. Inlatteryears,asassetmanagementpracticeswereimproved,systemswereintroducedwhichwerecapableofcollectingdetailedfielddataandelectronicallytransferringthesedatatotheGISforanalysis.

Best industrypractice calls foreach lineasset tohave its conditionassessed inat leastfive-yearly intervals.Westpower is achieving this by developing periodic maintenance schedules, which provides a systematicapproachtoensureitslines,remaininasafeandreliablecondition.

AfulltimeassessorusesanotebookcomputerequippedwithGPStechnologytorecordhis/herfindings,alongwithupdatinganyattributionthatmaybemissingoneachoftheassets.TheresultsaredownloadedintotheGISsystem,whichprovidesinstantanalysiscapabilities.ManyprojectsincludedintheAMPhavebeenderivedfromtheconditionassessmentprogramme.

Condition assessment results are used to remedy defects noted, of which, depending on urgency, can bescheduledforrepairorimmediatelyattendedto.

Justification:

Theconditionassessmentprogramme isacriticalcomponentwithinWestpower’spreventativemaintenancestrategy.Onceperceivedasawetdayfill-injob,theprogrammehasbeentakenfarmoreseriouslyinthelastdecadeandiscrucialinallowingconstantmonitoringoftheconditionoftheofthenetwork.Toensuresuccessfulmanagement of Westpower’s assets a programme such as condition assessment must continue and, withadvancesintechnology,willbecomeanevenmoreintegralpartofthemaintenancestrategy.


Condition assessment, regardless ofmethodology, hasbeenprovenas the industry standard formonitoringtheconditionofnetworkassetsandprovidingbasedataforanalysis.Withthisinmind,nootheroptionsareavailableforconsideration.Severalmethodsofobtainingresultshavebeenconsideredandwillcontinuetobeconsideredastechnologyadvances.

6.4.5 ProjectName:VegetationWorks

ProjectCode: NA

EstimatedCost: $736,000(perannum)




The inceptionof theElectricity (Hazards fromTrees)Regulations2003promptedWestpower to significantlyincrease its budget to ensure vegetation control notonly compliedwith thenew regulations, butprovide asysteminwhichconsumerscouldbecomfortableknowingthatvegetationwouldbeclearedfromlinesontheirpropertywithoutthetemptationtocarryoutanyvegetationcontrolworknearpowerlinesalso.

Sufficientfundshavebeenallocatedtoensureafullyequippedcrewisworkingfull-timeonvegetationcontrolandafulltimevegetationadministratorensuresthattheworkiscarriedoutinasystematicmanner,thatfulfilsregulatoryandlandownerobligations.

DuetothenatureoftheWestCoast’senvironment,whichlendsitselftohighvegetativegrowth,andtheremote,sometimesinaccessibleareasmanylinestraverse,controlofvegetationcanbeextremelychallengingandtheintroductionofheavymachinerysuchasexcavatorshasbecomecommonplace.Thismethodgenerallyclearstroublesomeareastoapointwhereminimalmaintenanceisrequiredtokeeptheseareasmanageableinthefutureandalsoprovidessomedegreeofaccess.Inmanycases,onceanareaofvegetationhasbeencleared,asprayprogrammeisinitiatedtomaintaintheremnants.

Ahighpriorityhasbeenawardedto66kVsubtransmissionlines,particularlythosethatdonotboastn-1security,withmostareasclearedtofalldistancetoavoidanychanceoftreestrike.Landownersaregenerallyacceptingoftheconsequencesthatsuchastrikewouldhave,andWestpowerworkshardtoengagewiththeselandownerstoreachamicableagreementsregardingvegetationontheirpropertyandproximitytothelines.

Justification:

Aswellascomplyingwithrelevantregulations,Westpower’svegetationcontrolprogrammeproducesahigherdegreeofconfidenceinthesafetyofnetworkalongwithsignificantlyimprovednetworkreliability. Withthepreferredoptionoffellingtreesbeingadoptedwherepossible,asopposedtotheextensivetrimmingpreviouslycarriedout,lessongoingmaintenancecouldbeexpected.Althoughitcouldbesaidthatcostsshouldbelessduetothenumberoftreesbeingfelled,thefundsbudgetedactuallyincreaseastheamountofmaintenanceworkwouldremainstaticandinflationarymeasurehavebeentaken.


Assafetyandregulatoryobligationsdeterminetheamountofvegetationworkrequiredtobecarriedout,nootheroptionswereconsidered.


7.0 FINANCIAL SUMMARY

7.1 Financial Forecasts

Thefinancialexpendituresinthissectionareforecastforaten-yearperiod.TheseforecastshavebeenbuiltupfromtheindividualprojectandprogrammeexpendituresdevelopedinSection5,anddemonstrateagenerallystableexpenditureoverthedurationoftheplanningperiod.

Formoredetailsregardingexpenditureforecastsandreconciliation,pleaserefertoAppendixD.

Table7.1belowshowstheprojectedten-yearAMPexpenditurebyactivityandTables7.2,7.3and7.4showthisexpenditurebyassettype.AgraphicalrepresentationofTable7.1isshowninFigure7.5.

Table 7.1 - Summary of Activity ($000)

Activity 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Inspect,ServiceandTest 4180 4361 4468 4580 4650 4477 4648 4862 5099 5323

Faults 541 571 607 641 680 717 759 803 850 899

Repairs 302 318 335 352 371 390 411 432 457 480

Maintenance Total 5023 5250 5410 5573 5701 5584 5818 6097 6406 6702

Replacement 2414 1235 611 881 727 842 669 1433 1374 1029

Enhancement 2111 260 246 188 228 203 543 164 223 194

Development 1437 1014 947 1095 1024 1004 1080 1209 1185 1269

Capital Total 5962 2509 1804 2164 1979 2049 2292 2806 2782 2492

Total 10985 7759 7214 7737 7680 7633 8110 8903 9188 9194

Table 7.2 - Opex - Summary by Asset Type (‘000)

2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Sub-Transmission 708 731 758 790 827 854 895 946 1002 1057

Distribution 1560 1599 1648 1678 1761 1838 1890 1976 2061 2137

Reticulation 276 289 292 285 242 236 250 266 282 298

Service 155 164 161 171 182 192 204 216 230 243

ZoneSubsubstation 751 819 896 998 954 1005 1056 1111 1167 1225

DistributionSubstation 777 807 822 802 848 521 550 584 620 659

MVSwitchgear 236 246 230 240 256 270 287 303 321 337

Scada&Comms 450 479 479 478 492 521 531 528 546 561

DistributionTrans-former 98 104 110 117 124 131 138 148 157 165

Other 12 12 14 14 15 16 17 19 20 20

Total 5023 5250 5410 5573 5701 5584 5818 6097 6406 6702

Table 7.3 - Replacement Capex - Summary by Asset Type (‘000)

2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Sub-transmission 948 125 98 102 105 93 97 102 107 113

Distribution 435 325 110 110 110 110 110 110 110 110

Reticulation 90 27 29 30 32 20 21 22 24 25

ZoneSubstation 668 620 173 348 286 245 25 761 761 321


MVSwitchgear 123 39 42 105 48 50 53 133 61 64

SCADAComms 60 35 92 115 70 244 278 215 215 295

Services 60 64 67 71 76 80 85 90 96 101

Total 2414 1235 611 881 727 842 669 1433 1374 1029

FINANCIALSUMMARY 229

Itshouldbenotedthattheestimatesforthefirsthalfoftheplanningperiodarebasedonknowndriversandhencearemoreaccuratethanthoseforthesecondhalf,whicharemoreinthenatureofforecastsduetoalargenumberofunpredictablefactors.Nevertheless,indevelopingthesefigures,Westpowerhashadseveralyearsofexperienceinbudgetingandcontrollingthisexpenditure,andthereisahighdegreeofconfidenceinthesevalues.

Figure7.5showstherelativepercentagesofthetotalestimatedexpenditureasapiechartfor2012-13basedonthefiguresshowninTable7.1.Figure7.7showstherelativepercentagesofthetotalestimatedexpenditureasapiechartfor2012-13basedonthefiguresshowninTable7.2.

ThemanagementfeeincludedinI,SandT,ispartofafixedannualfeepaidtothemaintenancecontractortocovercostssuchassparetransformermanagementandtheprovisionofotherwiseuneconomicfaultbasesatReeftonandHarihari.

Acontingencysumhasalsobeenprovidedtoallowforunexpectedevents.Thisisespeciallynecessaryinthefaultactivityareawhereexpenditureishighlydependentonweatherconditions.Infact,justafewseverelightningstormscanhaveamajorimpactontheannualresult.

Previously, Westpower had a large proportion of older lines that were rapidly approaching failure, but areplacementprogrammeoverthelasttenyearshassubstantiallyovercomethisissue.

Figure7.5-RelativeExpenditurebyActivity2009-10

39%

5%3%

23%

20%

10%

Inspect, Service and Test Faults

Repairs Replacement

Enhancement Development

Table 7.4 - Development and Enhancement Capex - Summary by Asset Type (‘000)

Asset Type 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

Sub-Transmission 1850 0 0 0 0 0 0 0 0 0

Distribution 14 65 66 67 18 19 20 21 22 24

Reticulation 0 50 0 0 0 0 0 0 0 0

Service 85 90 94 99 105 110 116 123 130 137

ZoneSubsubstation 36 0 0 0 0 0 315 0 0 0


MVSwitchgear 463 175 142 188 111 117 123 218 137 143

Scada&Comms 460 286 247 245 293 193 235 147 203 189

DistributionTransformer 449 476 504 535 567 601 637 675 716 759

Other 0 0 0 0 0 0 0 0 0 0

Total 3548 1274 1193 1283 1252 1207 1623 1373 1408 1463


TheI,SandTexpenditurehasincreasedduetoamorerigorousconditionassessmentprogrammeincludingCATscanningofwoodenpolesforrot,alongwithanupwardmovementincontractorrates.

The enhancement expenditure reflects a continued emphasis on distribution automation as reclosers anddisconnectorsareprogressivelyautomated.Bydoingthis,Westpowerisabletogreatlyreduceoutagedurationsandswitchingtimes,resultinginanimprovedSAIDIreliabilitystatistic.

AssettypessuchasZoneSubstations,andSCADAComms,andprotectionexhibitarelativelyyoungageprofile,andlittleongoingmaintenanceisrequired.Notsurprisingly,theseassetsalsohavethelowestsusceptibilitytofaultfailure.Notwithstandingthesecomments,anumberofoldercircuitbreakersinstalledatthesmallerzonesubstationshavebeenfoundtobeunreliableandareplacementprogrammehasbeeninstituted,whichshouldbecompletedin2012/13.

Figure7.6-ExpenditurebyActivityforthePlanningPeriod2012-21

0

2000

4000

6000

8000

10000

12000

2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

$('

000)

Year

Inspect, Service and Test Faults Repairs Replacement Enhancement Development

14%

31%

6%3%15%

15%

5%9%

2% 0%

Sub-Transmission Distribution Reticulation

Service Zone Subsubstation Distribution Substation

MV Switchgear Scada & Comms Distribution Transformer

Other

Figure7.7-RelativeExpenditurebyActivity2009-10


7.2 Assumptions and Sensitivity Analysis

Somebasicassumptionshavebeenmade.Theseinclude:

• AsanELB’s,Westpowerwillcontinuetobeagoingconcernunderthenewregulatoryregime.

• AssetManagement,systemcontrolandcorporateservicesfunctionswillbeprovidedbyElectroNetServicesandbebasedinGreymouth.

• TheELB’swillcontinuetoownElectroNetServicesandtooperateitonanarms-lengthbasis.

• TheELB’smust satisfy the twinconstraintsofprovidinga risk-adjustednormalprofit for itsbeneficiariessufficient to retain investment, while simultaneously performing within the regulatory limits set bygovernmentregulations.

Otherfactorsthatwillimpactonnetworkexpenditurearediscussedbelow.

7.2.1 Weatherimpacts

Weatheraffectsthefaultexpenditurethroughthelevelofstormdamageexperienced.Asitisverydifficulttopredictweatherpatternsovera12-monthperiod, thebudget for faultexpenditurecanonlybeanestimatebasedonhistoricalaveragesandgeneralknowledgeoftheassetcondition.

The sensitivity of the network to storm damage has greatly reduced over the last 20 years as major sub-transmissionanddistributionfeedershavebeenprogressivelyreplacedwithbetterqualitymaterials.Lightningarrestorshavebeenplacedonallsubstationsandrecloserstoprotectthatequipmentduringlightningstorms.Inaddition,acontinuingdistributionautomationprogrammehasreducedtheamountoftimeandeffortrequiredforfaultlocationandrepair.

Ontheotherhand,extremeweathereventsoverthelastfive-yearshavehadanotableimpactonperformancestatistics suchasSAIDIand soa continuationof thefiveyear rollingaveragehasbeenassumed toestimateforwardfaultandrepairexpenditure.

7.2.2 GrowthForecasting

GrowthhasbeenallowedforatarateequivalenttotheStatisticsNewZealandhighgrowthprojectionsforthedistrict.TheAMPassumesthattheregion’spopulationwillincreasebyanaverageofapproximately0.4%perannum.

GrossDomesticProduct(GDP)ontheWestCoasthasadirecteffectonWestpower’srevenuestreamthroughreduceddistributiontolargecustomers.Italsohasanindirecteffectassecondaryandtertiarylevelconsumersinthecommercialanddomesticareacontract.

TheuseofaLoadwatchspreadsheettocollectallavailableinformationonfutureloadgrowthtrendshasbeenusedasastartingpointintheplanningprocess.Wheretheloadsarenotyetcommitted,probabilitieshavebeenappliedaccordingtoanassessmentofthelikelihoodofaprojectproceeding.Inaddition,thediversityofanyloadneedstobeconsideredandadiversityfactorof30%hasbeenapplied,asthisistheaverageloadfactorexperiencedonthenetwork.Wherea loadwill clearlyhaveadifferentprofile, suchasan industrialprocessindustrythatrunsaroundtheclock,anindividualdiversityfactorisappliedthatisrelevanttothatparticularload.

WithintheAMP,growthhasbeenbasedonknownstepchanges.Iftherearenoknownsteploads,thengrowthisassumedtobestraight-linebetweenyears.Theseassumptionshavebeenappliedwhenprojectingexpenditureandgrowthovertheten-yearperiod.Theprojectionsfordifferentassettypeswillvarydependingontheamountofsystemreinforcementrequiredforeachload.


7.2.3 ContinuanceofSupply

AkeyassumptionisthatWestpowerwillberequiredtocontinuetosupplyexistingcustomersonitsnetworkfortheforeseeablefutureandthatthekeyfeaturesoftheElectricityIndustryReformBillregardingcontinuanceofsupplywillbepassedintolaw.

7.2.4 GovernanceStructure

Itisassumedthatthegovernancestructurewillremaininthestateasanticipatedbythisplanoverthedurationofthisplan.

7.2.5 DevolutionsofResponsibility

Forthepurposesofthisplan,itisassumedthattherewillbenodevolutionsofadditionalresponsibilityfromaregulatoryperspective,particularlynotwithouttheabilitytorecoveranyincreasedcoststhroughacommensurateincreaseinrevenue.

7.2.6 AssumptionsastoActivitiesUndertakenandLevelsofServiceProvided

Westpowerisassumingthattherangeofactivitiesthatithassignalledtoundertakewillnotchange.

Westpowerisalsoassumingthatthelevelsofservicetowhichitsactivitiesareprovidedwillnotchange,exceptasaconsequenceofplannedexpenditureprogrammesmentionedinthisplan.Therealityisthatanychangetoserviceleveland/oractivitiesundertakenmayplaceanadditionalcostonWestpower,andtherecoveryofthiscostwouldneedtobefairlyandequitablyallocatedtothechiefbeneficiaries.

7.2.7 FixedAssetUsefulLife

Anumberof assumptionshavebeenmadeabout theuseful livesofWestpower’s infrastructureassets. ThedetailforeachassetcategoryisgenerallybasedontheguidelinesprovidedinthelatestODVhandbook.Theusefullivesareconsistentwiththeassumptionsappliedtovaluingeachassetcategoryandweredeterminedbyexperiencedandqualifiedassetengineeringstaff.

Individualassetlivesareappliedtoassetsthatareeitherexpectedtolastlongerorlessthanthestandardvaluesbecauseoftheasset,conditionorenvironmentalfactors,suchasproximitytoacorrosivecoastalenvironment.

7.2.8 ResourceConsents

Westpowerisassumingthatthemajorresourceconsentsthatitneedsfordeliveryoftheservicesoutlinedinthisplanwillbeobtainedandgrantedwithconditionsthatcanbemetwithinanticipatedexpenditureestimates.

7.2.9 VestingAssets

ForthepurposesofthisplanithasbeenassumedtherewillbevestingofassetsinWestpower.Thishasbeenbasedonhistoricalinformation.However,itisnotedthattheyare:

• BeyondWestpower’scontrolandtheirnumberandvalueareverydifficulttopredict;

• Likelytobeimmaterialinthecontextofoverallassetvalues;

• Beingbrandnew,unlikelytoimposeanysignificantextracostsfromthosegeneratedoverthelifeofthisplan.


7.2.10 Sustainability

WestpowerhasconsideredthesustainabilityofeachofitsservicesandactivitiesinitspreparationoftheAMPalongsidehowtheservicesitprovideswillmeettheneedsofpresentandfuturegenerations,andhowitsactivitieswillprotectandenhancethenaturalenvironmentinthelongterm.Whilethecompanyisprimarilyrequiredtoact ina commercialmannerand remainagoing concern, it is also cognisantof its responsibilities to takeasustainabledevelopmentapproachtoprovidingforthesocial,economic,environmentalandculturalwellbeingof communities. This involves taking account of the needs of people and communities now, the reasonablyforeseeableneedsoffuturegenerations,andtheneedtomaintainandenhancethequalityoftheenvironment.

TakingasustainabledevelopmentapproachisreflectedinthewayWestpowerplansforasustainablesupplyofelectricitythroughoutitsarea,

Westpower has a significant role in the provision and operation of key infrastructure that is critical for thesustainabledevelopmentofthecommunitiesthatitserves.

7.2.10.1EffectsofClimateChange

ItisassumedthattheclimatechangereportsprovidedbytheIntergovernmentalPanelonClimateChange(IPCC)arereliableandprovideareasonableindicationofwhatWestpowerneedstoconsiderinitsplanningprocesses.BasedontheIPCCreports,itisassumedthatthesealevelwillriseby0.5moverthenext100years.

7.2.10.2EmissionsTradingScheme

ThisTen-yearAMPhasbeenpreparedbasedonthebroadscientificcommunityviewthathuman-inducedclimatechangethroughincreasedgreenhousegasemissionsisoccurringandmayaccelerateinthefuture.Nationalandinternationaleffortsareunderway tocontrolemissions in response toagreements that thegovernment isasignatoryto.

Manyoftheclimatechange-inducedchangesarelikelytoeventuateoverthelongertermandwilloccurbeyondthe ten-year horizon uponwhich the activities and their service levels are described in this AMP. They are,however,factorstobetakenintoaccountsuchasincreasedelectricitypricesdrivingadditionalinvestmentindistributedrenewablegenerationandthisneedstobecateredforinWestpower’splanningprocesses.

Table 7.8 – Sensitivity Analysis

Forecasting Assumption Level of Uncertainty Risk Assessment (Low/

Med/High) Reasoning for Assessment

LoadGrowthItislikelythatthepro-

jectedloadgrowthwillinrealitybedifferent

High

TheAssetManagementPlanhasassumedgrowthwilloccurbetweenthemid-highrangeoftheNZStatisticsprojections,

whichisthebestinformationwehaveavailable,supplementedbyknowledgeofparticularregionaldevelopmentsbasedontheLoadwatchspreadsheet.Theimpactofanychangeform

theprojectionwillbeoncapitalexpenditureasmanysteploadsrequireaugmentationofthenetwork.Theimpactonmainte-nanceexpenditureislesssignificant.Ifgrowthslowsthenex-penditurewillbedeferredandtheassetwillstillhavesufficientcapacity.Manyoftheengineeringsolutionscaterforgrowthupto20yearsout;howeverifgrowthisfasterthanforecastitmaymeanatsomestageinthefutureupgradesmayneedtooccursoonerthananticipated.Thisconsideredahighrisk,butlargely

beyondWestpower’scontrol.


7.3 Actual Deviations from Previous AMPs

7.3.1 UnallocatedWorks

Thefollowingexplainsadditionalworks(over$10,000)thatwerenotincludedinthe2010-11AMP,butwhichforvariousreasons,wereundertaken.

7.3.1.1 Network

PAS55 and SMS Consultancy Fees

ToassistwiththeimplementationofthePAS55andSMSsystems,aconsultantwasengagedtoprovideexpertiseinthesefieldsatacostof$36,750

Purchase and Installation of Productivity Plus and Template Manager

To assist in the development of Network Standards, appropriate softwarewas required. This included thepurchaseandinstallationofProductivityPlusandTemplateManageratacostof$15,365

7.3.1.2 Reticulation

Scandinavian Street, Stafford – Replace Overhead Line with Underground

ArequestfromalandownertorelocateacondemnedLVreticulationlinetraversingtheirpropertyatStaffordresultedinthelinebeingconvertedtoundergroundandinstalledonroadreserve.Thisremovedthelinefromprivatepropertyandhasallowedasafer,morereliableconfigurationatacostof$14,907

O’Conner Moonlight - Replace LV Line

TheLVlineemanatingfromS951ontheO’ConnorpropertyatMoonlightwasfoundtobeinasub-standardconditionandrequiresreplacement.Itappearsthepolesinstalledinthe1980’swerepre-usedandreachedtheendoftheirserviceablelives.Fourhardwoodpoleswerereplacedwithsixconcretepolestobringthelinetoregulatoryspecifications,eliminatingthelongspansthatwereoriginallyinstalledcosting$11,611

Table 7.8 – Sensitivity Analysis

Forecasting Assumption Level of Uncertainty Risk Assessment (Low/

Med/High) Reasoning for Assessment

ContinuanceofSupply

Itispossible,butun-likely,thatWestpower

willnotneedtocontinuesupplyingexistingcus-

tomers

Low

AkeyassumptionisthatWestpowerwillneedtocontinuetomaintainandreplaceolderlinesthatfeedcustomersinrural

areas.Itishardtoseeanygovernmentremovingtheprotectionthatmanyfarmingcommunitiesrelyonintermsofhavingalongtermguaranteethatelectricitysupplywillcontinuetobeavailableatcurrentprices,aftertakinginflationintoaccount.Atthesametime,Westpower’snetworkisinverygoodcondi-tionwithfewareasrequiringmajorrefurbishmentwithintheplanningperiodandsoanyextendedobligationwillhavelittle

impactintheshorttomediumterm.

GovernanceStructure

Itisimprobablethatthegovernancestructurewill

changeLow

Recentownershipreviewsandthecurrentlysupportiveregula-toryframeworkfortrust-ownedlinesbusinessesmeansthat

theredonotappeartobeanysignificantdriversforachangeinthecurrentgovernancestructure.

ActivitiesUndertaken

Itislikelythatnewactivi-tieswillbeundertaken. Low

AlthoughWestpowerisinvolvedinanumberofrelatedactivi-tiesthroughitssubsidiarycompanies,andthisislikelytoin-

creaseovertime,theimpactiontheAMPisnotgreatasaclearfocuswillalwaysbemaintainedontheasset.


7.3.1.3 Distribution

Omoto – Kaiata 11 kV Line Replacement

IncludedinpreviousAMP’s,thereplacementofthe11kVlinebetweenOmotoandKaiatawasnotcompletedin2009-10asanticipated.The$39,369additionalexpenditurewascarriedoverfromthepreviousyearandtheprojectwascompleted.

Giles Creek 11 kV Reconstruction

ThelineroutefortherecentlyconstructedDOB-TEEA110kVccttraversedtheroadadjacenttothe11kVlineatGilesCreek.Thisnecessitatedrelocationofthe11kVlinetoaccommodatethe110kVcct.Duetothepoorconditionofthehardwoodpolesaffected,andthefactthattheywouldhavebeenreplacedinthenearfuture,Westpowerfundedthemajorityoftherelocationatacostof$17287.

7.3.1.4 Subtransmission

GYM-KUM 66 kV cct – Carry Out Rating Study

ToensureWestpoweradherestocontractualobligationsanddoesnotcompromiseregulationsbyintroducingconductor clearance violations, a study was undertaken to model the existing line configuration on theGreymouthtoKumara66kVcircuitusingLiDARtechnologyandPLSCADlinedesignsoftware.Severalscenarioswithdifferentoperatingparametersweremodeled,atacostof$11,815

KUM-KAW Install Conduit and Saddle Earths on KUM-KAW Circuit

AnassessmentoftheKUM-KAW66kVcctrevealedthatthehardwoodpolesonthelinehadexposedcopperearthleadstogroundlevel,whichgivenpublicsafetyconsiderations,requiredaprotectivesheathtobeinstalled.AllsixtyeightpoleshadPVChosesfittedovertheearthleadsatacostof$11,499

7.3.1.5 ZoneSubstations

44027: Longford Corner – Replace Regulator with Single Phase Units

Thisprojectwassetdownforthe2012/13financialyear.InSeptember2011amajorfaultoccurredwiththeunit.Duetoitsage,difficultyinsourcingpartsandthefactitwasalreadysetdownforreplacementitwasdecidedtoreplacetheunit.Totalcostsforthiswas$68,928

7.3.2 UncommencedWorks

Thefollowingexplainsprojects(over$10,000)thatwerenotcommencedinthe2010-11AMP.

7.3.2.1 Reticulation

61008 – Offload S119 Frickleton St ($50,000)

Relatedtotheabove,adistributionsubstationwasconsideredtoalleviatevoltageissuesintheFreybergTerracearea.Furtheranalysiswascarriedoutanditwasdiscoveredthatbyre-configuringtheexistingLVconfigurationvoltagecouldbesuppliedatacceptablelevels,negatingtheneedfortheadditionalsubstation.

42003 - Ruatapu Township - Replace LV ($22,000)

ItwasintendedtoreconfiguretheLVlinesaroundtheRuataputownship,howeveritwasfeltadditionalplanningwasrequiredbeforeworkcouldtakeplace.Thisplanningextendedoverthefinancialyearthereforetheprojectdidnotcommence.


12003 - Hokitika, Hampden St - Remove LV ($15,000)

Itwas intendedtoremovethesurplusLValongasectionofHampdenStreet inHokitika,however itwasfeltadditionalplanningwasrequiredbeforeworkcouldtakeplace.Thisplanningextendedoverthefinancialyearthereforetheprojectdidnotcommence.

7.3.2.2 Distribution

61003 - Construct 11 kV Line to Freyberg Terrace ($50,000)

Considerationwasgiventoconstructan11kVlinetoFreybergTerracetoalleviatevoltageissuesinthearea.Furtheranalysiswascarriedoutanditwasdiscoveredthatbyre-configuringtheexistingLVconfigurationvoltagecouldbesuppliedatacceptablelevels,negatingtheneedforthe11kVline.

41029 - Waitahu, Douglas Road - Replace 11 kV Line S1363 ($30,000)

Conditionassessmentofthe11kVlinetraversingDouglasRoadatWaitahurevealedthatthepoleswereredtaggedandrequiredreplacement.Fundsweremadeavailable,howeveritwaslaterdiscoveredthatthelinewasnolongerrequiredthereforedismantled.

61007 Replace 11 kV cable Fox Hotel ($100,000)

Replacementoftheageing11kVcable,creatingan11kVringintheFoxGlaciertownship,waslargelydependentonobtainingeasementsoveranumberofproperties.Asnegotiationswithlandownershadnotbeenfinalisedworkcouldnotcommence.

7.3.2.3 Subtransmission

10005 – Franz Josef - Fox Glacier 33 kV Line Maintenance ($22,000)

ContingencyfundsweremadeavailableforgeneralmaintenanceontheFRZ-FOX33kVcct,howeverpatrolsandassessmentdidnotidentifyanymajormaintenance.

40008 - Replace All 33 kV EPDM Strain Insulators ($28,000)

AcontingencysumwasallocatedtohaveallEPDMstraininsulatorsonthenetworkremovedandreplacedwithglassequivalents.ThiswasdependantonidentificationofEPDMstraininsulatorsandappropriateoutagestohavethemreplaced.Thisprojectdidnotcommenceduetothelackofidentifiedinsulators.

40006 - Replace Waitangitaroa River crossing ($40,000)

SignificantdesignwasrequiredtodeterminethebestoptiontohavetheWaitangitaroaRivercrossingreplaced,stallingtheconstructionaspectoftheproject.

7.3.2.4 ZoneSubstation

14005 – Greymouth Zone Substation Paint Gantry Steelwork $75,000

DetailedinspectionoftheGantryhasdeterminedthattheSteelworkisingoodconditionandrequiresnofurtheractionatthistime.Thiswasacontingencybudgetthathadbeenallowedforincaseoffurtherworkrequiredafterinspection.

14010 – Rapahoe Zone Substation Paint Gantry Steelwork and Reinsulate $33,000

ThisprojecthasbeendeferredtocoincidewithEquipmentandProtectionupgradeattheZoneSubstationin2014/15ensuringbetterutilisationoftheMobileSubstationandotherresources.

14023 – Zone Substation Lightning Protection Review $12,000

Thisprojecthasbeendeferredduetoengineeringresourceconstraints.


14040 – WMS (Mobile Substation) Storage $12,000

DelaysinstoragebeingbuiltbyCroft’satStillwaterhaveseennocostsincurredonthiscontingencybudget.

44020 – Rapahoe Zone Substation 33kV Disconnector Upgrade $25,000

ThisprojecthasbeendeferredtocoincidewithotherprojectworkplannedattheZoneSubstationin2014/15ensuringbetterutilisationoftheMobileSubstationandotherresources.

44022 – Whataroa Zone Substation Design/Drawings for CB1412 and T1 Protection upgrade $12,000

Thisprojecthasbeendeferredto2012/13duetoengineeringresourceconstraints.

54018 – Wahapo Zone Substation 11kV BUS upgrade with RMU $50,000

PrioritisingofresourcesduetoexternalcommitmentsandEngineeringresourceconstraintshasresultedinthisprojectbeingdeferredto2012/13.

64008–Emergency backup Control Room $30,000

Thisprojecthasbeenputonhold.

7.3.2.5 MVSwitchgear

56004–Distribution intelligent fault isolation system, design/study $11,000

Timingforthisprojectwasnotsuitable.TheMVswitchgearupgradeworkbeingcarriedoutonthenetworkatpresent,whichisdueforcompletioninacoupleofyears,willallowthisprojecttocommencewithdevelopmentofasmartgrid.

66006–Install Ring Main Units – Unspecified Locations (1) $45,000

Thisisacontingencybudgetallowedforanyunplannedsuppliesfornewdevelopments(Subdivisions,etc.).Nonewdevelopmentsoccurredinthisfinancialperiodrequiringtheuseoftheallocatedfunds.

7.3.3 UncompletedWorks

Thefollowingexplainsprojectsthatwerestartedandhavemorethan$20,000remaininginthe2011-12AMP.

7.3.3.1 ZoneSubstations

14030 - Zone Substation Building Climate Control $44,000

ThisbudgetwasoriginallyallowedfortoinstallAirConditioningUnitsatallZoneSubstations.Adecisionhasnowbeenmade to not install the units in the smaller Zone Substation control rooms constructedwith the‘TransportableSandwich’Panels.Thishasresultedinanunderspendof$33,282.

14032 - Zone Substation OLTC & Regulator Maintenance $91,000

DuetoresourceconstraintsthenumberofOLTCandRegulatorstomaintainwasreduced.Allworkabletobecompletedwasdoneatacostof$14,900resultinginanunderspendof$76,100.

44015 - Wahapo Substation Replace Combiflex Relays, Protection Setting upgrade $ 53,000

PrioritisingofresourcesduetoexternalcommitmentsandEngineeringresourceconstraintshasresultedinthisprojectbeingdeferredto2012/13.Designworkhasbeencompleted,remainingbudgetof$42,421.


44021 - Ngahere Zone Substation – CB1 & 3 Replacement $108,000

Delaysinthedesigndrawingsandthelongleadtimeinorderingequipmentresultedinthisprojectbeingdeferredto2012/13,remainingbudgetof$84,813.

7.3.3.2 MVSwitchgear

16001 – Upgrade Earthing at Disconnector Locations $24,000

AdelayintheEarthingdesignhasseenthisprojectdelayedto2012/13,remainingbudgetof$22,936.

16003 – Recloser Maintenance – Protection, Batteries, etc. $28,000

AnumberoflocationsduefortestingandbatteryreplacementwereupgradedwithneworrefurbishedReclosers.Thisresultedinanunderspendof$25,644forthiscontingencybudget.

46001 – Replace KFE Reclosers with Viper-ST & SEL Protection $278,000

80%oftheplannedworkwascarriedout.Theremaining20%istobecompletedin2012/13.Resourceconstraintsandreducedcostsforthecompletedworkresultedinanunderspendof$67,052.

46006: Ring main unit Replacement $56,000.

ARingMainUnitwaspurchasedtoreplaceanexistingunitatFoxGlacier.Issueswereencounteredwithobtaininganeasementforthecables,thisalongwithresourceconstraintsresultedinanunderspendof$35,301.

56005: Install Automation to various Disconnectors $84,000.

Furtheranalysisdeterminedthat2locationswerenolongerrequired.Theremaininglocationswerecompletedresultinginanunderspendof$41,263.

56006: Fit Fault Passage Indicators $24,000.

ThisisacontingencybudgetallowedforanynewlocationsidentifiedrequiringFaultPassageIndication.Only2locationswereidentifiedinthisperiodleaving$23,369unspent.

56007 - South Westland 33 kV disconnector automation $80,000

45%of locationshavebeencompleted,resourceconstraintsand issueswiththeActuatorsresultedwiththeremaininglocationsbeingdeferredto2012/13andanunderspendof$42,262.

66001 - New main line recloser sites $191,000

60%oftheplannedworkwascarriedout.Resourceconstraintsresultedintheremaininglocationsbeingdeferredto2012/13.Thisalongwithreducedcostswithcompletedworkresultedinanunderspendof$58,687.

66002 - New spur line recloser on various spur lines $191,000

50%oftheplannedworkwascarriedout.Resourceconstraintsresultedintheremaininglocationsbeingdeferredto2012/13.Thisalongwithreducedcostswithcompletedworkresultedinanunderspendof$93,070.

66005 – Install Capacitors at various Locations $40,000

TheEngineeringstaffisstillinvestigatingavailablecosteffectivesolutionsforautomationofCapacitorLocations.OnelocationwasidentifiedrequiringsmallersizedCapacitors.Thisresultedinanunderspendof$35,277.


66006 - Install ring main units–unspecified locations $42,000

Therewerenonew locations identified for this financial period, resulting in an approximateunderspendon$33,000.


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0046

993

3900

093

4194

1219

000

7:SC

ADA/

Comms

1426

050

8957

00

3802

90

2358

600

3270

10

2900

80

5677

720

8:Distrib

ution

Tran

s31

6562

4000

000

014

816

6200

079

789

9600

00

3000

00

4111

6756

1000

9:Other

1568

00

00

030

1519

000

4325

6000

010

0089

0826

000

Total

9710

1897

8000

4778

6754

5000

2540

689

1966

000

3921

551

3368

000

5847

2941

0000

2800

5927

0000

8775

913

7537

000

Table7.9-A

ctua

lVBud

getP

erform

ancebyAssetT

ype

ASSETMANAGEMENTPRACTICES 241

8.0 ASSET MANAGEMENT PRACTICES

8.1 Introduction

The electricity distribution system is comprised of assets with long lives. Themanagement of these assets(includingmaintenance of existing assets and development of new assets) isWestpower’s primary focus inprovidinganeffectiveandefficientdistributionserviceto itscustomers.Furthermore,becausedistributionisonlyonepartofanintegratedelectricitysystem,consultationandcoordinationofplansisanessentialingredientfortheeffectivefunctioningofthatsystem.

Thisisanannuallyproducedplancoveringthenexttenyearsanddocumentslikelyorintendedassetmanagementrequirements.TheplanprovidesafocusforongoinganalysiswithinWestpoweraimedatcontinuouslyimprovingthemanagementofthedistributionsystemanditprovidesavehicleforcommunicatingAMPswithcustomers.

Inmanycases,particularlywhereassetdevelopmentisinvolved,theworkwillbedrivendirectlybycustomerrequirementsandassociatedfinancialcommitments.ThisplanisbasedonWestpower’spresentunderstandingofitscustomers’requirements.Itispartoftheprocessofcommunicationwithcustomers,andWestpowerwillberesponsivetocustomerinput,withregardbothtoactualexpenditurecommitmentandtolong-termfutureplanning.

TheplanisalsointendedtodemonstrateresponsiblestewardshipofassetsbyWestpowertoitscustomersandshareholders.Theplanshowsthemaintenanceandreplacementrequirementswhichareintendedtomaintaintheoperating capabilityof the systemover the long term.Eachyearaprocess is carriedoutwhich reviewsWestpower’sachievementwithrespecttothisplanandtheresultsofthisaresummarisedintheprevioussection.

ThissectionbroadlyoutlinesWestpower’snetworkservices,currentanddesiredassetmanagementpracticesandspecificimprovementinitiatives.

Toidentifyandprioritisetheassetmanagementpracticesandneedsofnetworkservices,assetmanagementimprovementtasksarediscussedunderbroadheadingsofprocesses,informationsystemsanddata.

• Processes are the business processes, analysis and evaluation techniques needed for lifecycle assetmanagement.

• Informationsystemsaretheinformationsupportsystemsusedtostoreandmanagethedata.

• Dataarethoserequiredforeffectivedecisionmaking(i.e.formanagingusinginformationsystems).

TablesthroughoutthissectionbroadlydescribethecurrentWestpowerassetmanagementpracticesandpossiblefuture(desired)businesspractices it is intendedtoultimatelydevelop.Theassetmanagement Improvementplandiscussesimprovementpriorities,timetablesandresourcesforthenextthreeyears.

Thefollowingarespecificissuesandassetmanagementproceduresthatarecurrentlybeingaddressed.



The asset management policy is a direct communication from directors to management, employees andstakeholdersoftheorganisation’spositionandintentionswithregardtoassetmanagement.Itprovidesahighlevelstatementoftheorganisationsprinciples,approachandexpectationsrelatingtoassetmanagement.

Westpoweriscommittedtomaximisingshareholder’sinvestmentsinalegallyandenvironmentallycompliantandsustainablemanner,withoutcompromisingthehealthandsafetyofouremployees,consumersorthepublic.Thisshallbeachievedbyadoptingthefollowingpolicystatement:

1. Safety


2. Reliability

• Reliability of Supply - Through continued investment in relevant technology and system configuration,reliabilitymustmeetapprovedtargetsatalltimes;and

• QualityofSupply-Qualityofsupply,commensuratewiththeloadtypeandcriticality,mustmeetWestpower’sStandardsandremedialactionwillbetakenwherestandardsarenotmet.

3. Security

• SecurityofSupply–Thedesiredlevelofsecurityisdefinedbygoodindustrypracticesandlongtermplansmustbedevelopedtoachievetherequiredsecurity;and


4. Sustainable

• MaintainServicePotential-ThefutureofWestpower’sbusinessiswhollydependentoftheabilityofthenetworktocontinuetoprovideservicefortheforeseeablefuture.Everyeffortmustbemadetomaintaintheongoingservicepotentialofthenetworkwhereappropriate;

• Supporting Economic Growth -We recognise the electricity infrastructure is a key enabler of economicgrowthandwillworkwithcurrentandfuturedeveloperstoprovideelectricitywiththecapacity,securityandqualityrequiredtosupporttheirbusiness;

Figure8.1-AssetManagementSystemElements


• Continual Improvement–Theassetmanagementsystemwillbereviewedonanannualbasisandwhereweaknessisfound,improvementswillbemade.CompliancewithPAS55:2008,AssetManagement,shallbesupported;

• StrategicandLongTerm–Ourinfrastructurebusinessinvolveslongterminvestmentsandwewillensureourdecisionsalignwithandsupporttheorganisation’sstrategicplan;

• NewInvestment–Anynewinvestmenttoexpandtheassetbasemustmeetshareholderexpectationandapprovalwherenecessary;and

• Communication – The requirements of the asset management system must be communicated to allstakeholderstoenablethemtobeawareoftheirobligationsandtoensuretheirexpectationsareconsideredinallaspectsofplanning.

5. CostEfficiency

• CostEfficiency-Allprojectsmustcompeteforfinancialresourcesandprudentassetstewardshiprequirescareful budgeting and robust financial review processes are used to ensure maximum cost efficiency.Opportunitiesforimprovedproductivitythroughtraining,technology,processimprovementorothermeanswillbeconstantlypursued;

• EnergyEfficiency-EnergyefficiencyisencouragedinallareasofWestpower’sactivitiesandwillcontinuetobeakeyoutcomefromthedesignprocess.Whereopportunitiesexisttoenhanceenergyefficiencyforexistingassets,theseareactivelypursuedandimplementedwheretechnicallyandeconomicallyfeasible;

• Technology-Technologyisseenasakeyenablerinprovidingimprovedserviceandvaluetoourconsumers.WewillcontinuetokeepabreastofdevelopmentsinthefieldofnewandemergingtechnologyandapplythesetoWestpower’snetworkwhereappropriate;

• FairPricing-Thepriceofdeliveryofelectricitytocustomersmustbetransparentandfairtoallusersoftheassets;and

• CapitalContributions–Anyexpensefornetworkextensionstosupplynewloadswillbemetbyaconsumercontributiontowardsthecostsinvolved.

6. EnvironmentalImpact

• EnvironmentalImpact-Westpowerisenvironmentallyresponsibleandcarefullyconsiderstheenvironmentalimpactofanyof itsactions. Furthermore,thecompanyworkshardtomitigateanynegativeeffectsandprovideanetenvironmentalbenefitwherethisispractical.WestpowerconsiderstheclimatechangereportsprovidedbytheIntergovernmentalPanelonClimateChange(IPCC)arereliableandprovideareasonableindicationofwhatWestpowerneedstoconsiderinitsplanningprocesses.

7. RiskManagement

• Risk Management – Westpower adopts the AS/NZS ISO 31000:2009 standard in its approach to riskmanagementandhasaGroupRiskManagementPlanthatincludesBusinessImpactAnalysisandBusinessContinuityPlanning.TheAssetManagementSystemhasdevelopedariskmanagementplanrelatingdirectlytoWestpower’sdistributionassets.

8. Legislation

• Legislative Compliance – The AssetManagement Systemmustmeet all relevant legislation but the keylegislationistheElectricityActandtheHealthandSafetyinEmploymentAct.Wherenon-complianceissuesareidentified,thesewillbedealtwithpromptlyandtransparently.

9. AlignmentwithOtherPolicies

• TheassetmanagementsystempoliciesexpressedabovealignwithotherfunctionalpolicieswithinWestpower.

10.AuditandReview

Theassetmanagementpolicyshallbesubjecttoauditandreviewasperthefollowingprocess:


ReviewPeriod: FiveYears

PersonResponsible: WestpowerAssetManager

APPROVED:

Adopted: Date……………… Minuterecord………………….

RevisedDate……………… Minuterecord………………….

ChiefExecutive……………………………………………………………

8.3 Rationalisation of responsibilities and procedures

ThestructureofElectroNet’sassetmanagementgroup,reportingtoTheGeneralManager,AssetsandEngineeringServices,continuestodeveloptomeetbusinessneedsandlegislativechange.Responsibilities,reportinglines,workflowsandprocedureshavebeenimplementedforthedifferentactivitiescarriedoutintheoffice.Theseactivitiesincludeaction,planning,monitoringandreporting.

8.4 Network services operational support

WestpowerusesElectroNetServicesasitspreferredmaintenancecontractorforallnetworkassociatedinspectionservice and testing, faults, fault repair,maintenance replacement and network enhancement. Developmentprojectsarehandledinthesameway,althoughoutsidecontractorsmaybesub-contractedintocarryoutcarryoutsomeofthework.

Service level agreements are currently in place with ElectroNet services for asset management and assetmaintenance.Largerenhancementanddevelopmentprojectshavecontractspreparedonaspecificbasis.

8.5 Information systems development

TheassetmanagementgrouphasimplementedtheIBMMaximo®AssetWorksManagementSystem(AWMS)usedforassetandworksmanagementprocesses.Expenditurecanbetrackedbyactivityandbyassettype,andisauditedmonthly.

Improvements have been made to the Maximo® asset database, which keeps information on the typesof equipment installed at a site. This systemalso tracks themaintenancehistory of transformers andotherassociatedequipment.

8.6 Specifications, procedures and manuals

Westpowerisspendingconsiderableeffortinupdatingitsmanualsforeasierusebycontractors,whichdenoteWestpower’sspecifications, levelsofcompetency,networkreleasesandaccess tosites.Thecompletionofafullsuiteofmanualsandstandardssuitableforusebycontractorsisakeystrategicgoalduringthefirstyearoftheplanningperiod.Asetofnetworkdesignstandardsarealsoavailabletocontractorswhowishtoundertakenetworkextensionsandnetworkreconstruction.

ProcedureshavebeendevelopedanddeemedtobemandatoryforcontractorswhowishtocarryoutworkonWestpower’snetwork.

8.7 Deregulation/Compliance with MED and Commerce Commission Requirements

ThespecificexternalenvironmentinwhichWestpoweroperatesisthepowersupplyindustryingeneral.


8.8 Asset Renewal Policy

Thegeneralrenewalpolicyistorehabilitateorreplaceassetswhenjustifiedbyassetperformance.

Renewalof an asset is requiredwhen it fails tomeet the required level of service. Themonitoringof assetreliability, capacityandefficiencyduringplannedmaintenance inspectionsandoperationalactivity identifiesnon-performingassets.Indicatorsofnon-performingassetsinclude:

• Structurallife,

• Repeatedfailure,

• Ineffectiveand/oruneconomicoperation,

• Economics,

Renewalsareprogrammedwiththeobjectiveofachieving:

• Thelowestlifecyclecostfortheasset(uneconomictocontinuerepairing),

• Anaffordablemediumtermcashflow,

• Savingsbyco-ordinatingrenewalworkswithotherplannedworks.

• Riskreduction.

Theriskoffailureandassociatedenvironmental,publicsafety,financialorsocialimpactjustifiesproactiveaction(e.g.impactandextentofsupplydiscontinuation,probableextentofpropertydamage,healthrisketc.).

Plannedandreactivereplacementworkscanbeprioritised inaccordancewiththepriority rankingshown inTable8.2.

8.9 CAPEX Analysis

CAPEXneeds tobe carefully targeted to ensure that the greatest benefit is reaped fromeach capital dollarexpended.

WestpowerhasdevelopedaformalprocessforoptimisingitsCAPEXandthisinvolvestheuseofadiscountedcashflow(DCF)analysis,wherefeasible,alongwithothermethodstodeterminetheoptimalCAPEXprofile.TheprocessusedhasbeenexplainedinmoredetailinSection5.2.

Table 8.2 - Asset Renewal Criteria

Priority Renewal Criteria

1(High)

AssetFailurehasoccured.

AssetFailureofcriticalsystemcomponentisimminent.

Regularmaintenancerequired.

Complaints.

2Failureofnon-criticalassetisimminentandrenewalisthemostefficientlifecyclecostalternative.

Maintenancerequiringmorethansixvisitsperyear.

3Reticulationmaintenanceinvolvingtwotothreevisitsannually.

Difficulttorepair,duetofragilenatureofmaterialobsolescence.

4 Existingassetshavelowlevelofflexibilityandefficiencycomparedwithreplacementalternative.

5(Low) Existingassetmaterialsortypesaresuchthatknownproblemswilldevelopintime.


8.10 Distributed Generation

Distributedgenerationiselectricitygenerationequipmentconnectedtothecustomers’installations,andcapableofgeneratingelectricitybacktotheelectricitynetwork,aswellassupplyingelectricityforthecustomers’ownuseatthelocationitisinstalled.

Usually,itwillbeafixedinstallationbutitmaybedisconnectableandmoveableifrequired.Theinstallationwillincludeallnecessaryprotectionequipmentrequiredforthesafeoperationofthedistributedgenerationsystem.

InthecontextofWestpower’sguidesforconnection,distributedgenerationcomprises:

• Smallsystemsoflessthan5kWcapacity;

• Mediumsystemsofbetween5kWand30kWcapacity;

• Largesystemsbetween30kWand1000kWcapacity;

Largesystemswouldnormallybeassociatedwithindustrialsitesorasdedicatedgenerationfacilities.

Westpower’spolicyistoactivelyencouragedistributedgenerationasameansofreducingsystemlossesandimprovingboththereliabilityandqualityofsupplytothearea.

CustomersinterestedindevelopingsuchfacilitiesareinvitedtocontactWestpower’sagentElectroNetServicestorequestacopyofthedistributedgenerationinformationpack.Thispackwillprovidevaluableassistanceinplanningandengineeringanacceptablesolution.

Formal application forms will be available to ensure that the appropriate information is provided to allowWestpowertoapproveconnectiontoitsnetworkandensurecompatibilitywiththeexistingreticulationnetwork.

Anynewdistributedgeneration installationalsorequirescontractualarrangementstobeput inplacewitharetailertopurchaseanyexcesselectricitygenerated.Westpowermaythencredittheretailerfortheenergythatisexportedatthesamepricethattheretailerischargedforthedeliveryofenergy,providinganetbenefittothedistributedgenerator.

RefertoSection5.7formoredetailedinformation.

8.11 Asset Management System Improvement Process

8.11.1 IntroductiontoPAS-55

Westpower has evaluated its assetmanagement systems by conformingwith theU.K. specification PAS-55-1:2008.

PAS-55isthepubliclyavailablespecificationfortheoptimisedmanagementofphysicalassetsandinfrastructure.DevelopmentofPAS-55wassponsoredintheUnitedKingdombytheInstituteofassetmanagementinresponsetoaneedidentifiedbyregulatorsandassetowners.Thiswasdevelopedinordertodefineassetmanagementinthecontextofphysicalinfrastructurebysettingoutthekeyattributesofeffectiveassetmanagementsystems.

PAS-55 consists of 24 key requirementswhich together provide a framework defining current best practiceforthewhole-of-lifemanagementofphysicalassets.The24keyelements,showndiagrammaticallyabove inFigure8.2,worktogethertoprovidearigorousprocessbasedontheplan-do-check-actcycle.Therequirementslinkstrategicbusinessobjectivestodetailedoperationalplans,ensuringthatoperatingandcapitalinvestmentis targetedat realisingassetperformanceand riskprofiles thatmeet stakeholderexpectationsandbusinessobjectives.


PAS-55,whilenothavingthestatusofaBritishoranISOstandardisanauditablespecification.AssuchWestpowerwillseektoobtainindependentexternalcertificationverifyingconformancewiththedocumentedrequirements.Suchexternalcertification isbecomingrecognizedbyassetownersandregulators internationallyasausefulmeanstodemonstrategoodgovernance,duediligenceinthemanagementofassetrelatedriskandoptimizedassetmanagementdecisionmaking.

Todate,Westpowerhasdocumented95%oftheprocessesrequiredforconformitywithPAS-55andwillspendthenexttwelvemonthsimplementingtheseprocesses,reviewingtheireffectivenessandcommencingaprogramofcontinualimprovement

8.11.2 PurposeandObjectivesofthisReview

AdetailedgapanalysisofWestpower’sassetmanagementsystemhasbeenconductedagainsttherequirementsofPAS-55withtheobjectiveofconformanceorcertificationagainstthedocument.Theobjectivesofthisreviewwereto:

1. ProvideanunderstandingofWestpower’scurrentpositionwithconformancewithPAS-55.

2. Identify areaswhere changes to assetmanagement systemwould yield continual improvement in assetperformanceandriskmanagement.

4.4 Asset management enablers and controls

4.4.1 Structure, authority and responsibilities

4.4.2 Outsourcing of asset management activities

4.4.3 Training, awareness and competence

4.4.4 Communication, participation and consultation

4.4.5 Asset management system documentation

4.4.6 Information management

4.4.7 Risk management

4.4.8 Legal and other requirements

4.4.9 Management of change

4.5 Implementation of asset

management plans

4.5.1 Life cycle activities

4.5.2 Tools, facilities and equipment

4.3 Asset management strategy,

objectives and plans

4.3.1 Asset Management Strategy

4.3.2 Asset Management Objectives

4.3.3 Asset Management Plans

4.3.4 Contingency Plans

4.7 Management review 4.2 Asset Management Policy

4.1 General Requirements

PAS 55:2008

Management

system structure

Act Plan

Do

Check

4.6 Performance assessment

and improvement

4.6.1 Performance and condition

monitoring

4.6.2 Investigation of asset

related failures, incidents

and nonconformities

4.6.3 Evaluation of compliance

4.6.4 Audit

4.6.5 Improvement actions

4.6.6 Records

8.3-PASS-55AssetManagementSystemElements


8.11.3 ImprovementPlan

WestpowerhasadoptedprogressiontowardsPAS-55conformanceasakeyperformanceindicatorintheoverallbusinessStrategicPlan.

As part of this process, the Board signed off on the Asset Management Policy on (DATE), which providesthe governance framework for all asset management activities. This ensures strategic alignment betweenWestpower’sbusinessgoalsandmanagementoftheasset.

Overthenextyear,Westpowerplanstocompleteanumberofinitiativesaimedatreducingtheconformancegapsidentifiedintherestofthissection.

Keytargetsforthecomingyearinclude:

• AformalanddocumentedreviewoftheperformanceofthisAMPasrequiredbyPAS-55;

• Implementationoftheformallydocumentedassetmanagementsystem;and

• Attheendoftheperiod,reviewconformancewithPAS-55:2008;

• Preparingacompliancestrategyandtimeframe.

8.11.4 GapAnalysisAssessmentCriteria

PAS-55 contains 24 keymandatory requirementswhich canbe further subdivided to a total of 164discreteelements for evaluation. Questions chosen to reflect the intent of these elements were scored semi-quantitativelytoprovideameasureoftheorganisationalignmentormaturityinthatarea.AsummaryofthescoringmethodologyisshowninTable8.5below.

Figure8.4-PAS-55AssetManagementFramework


8.12 Detailed Findings

8.12.1 AssetManagementSystem

“Theorganisationshallestablish,documentandmaintainandcontinuallyimproveanAMSinaccordancewiththerequirementsofPAS-55.”

Review against PAS-55 Requirements

Observations and Improvement Opportunities

The intent of this group of requirements is that the organisation recognises asset management as a corebusinessfunction,anddemonstratescommitmenttothedevelopmentandcontinualimprovementoftheassetmanagementfunction.ThisisclearlyevidentwithinWestpowerthroughtheAMP,theSCIandtheorganisationstructure.

Table 8.5 - Gap Analysis Assessment Criteria

Rating % PAS 55 Maturity Level Evaluation Criteria

1 0 Innocent ThiselementofPAS55isnotinplace;theorganisationisunawareoftheneedforthiselement.

2 20 Aware TheorganisationhasabasicunderstandingoftherequirementsofthiselementofPAS55andisintheprocessofdecidinghowthiselementwillbeapplied.

3 40 DevelopingTheorganisationhasasoundunderstandingofthiselementofPAS-55.IthasbeendecidinghowthisPAS-55elementwillbeappliedandworkisprogressing

onimplementation.

4 60 Compliant ThiselementofPAS-55isimplementedasrequired;minorinconsistenciesmayexist.

5 80 Excellence ThiselementofPAS-55iscomprehensivelyimplementedandintegratedwithotherelements.

6 100 BeyondPAS55UsingprocessesandapproachesthatgobeyondtherequirementsofPAS-55,pushingtheboundariesofassetmanagementtodevelopnewconceptsand

ideas.

0

1

2

3

4

5

6

Esta

blish

an

d m

ain

tain

AM

S th

at co

nfo

rms to

all

req

uire

me

nts

of P

AS

55

-1.

AM

S d

eta

il a

nd

co

mp

lexity fits th

e s

ize

of

the

co

mp

an

y.

AM

S b

ou

nd

ary

is w

ell

de

fin

ed

.

An

effe

ctive

ove

rall

syste

m d

raw

ing

on

oth

er

co

mp

an

y s

yste

ms.

PAS-55 Aligned


TheconciseandauditabledocumentdefiningWestpower’sassetmanagementsystemclarifiesassetmanagementprocessesandenhancesWestpower’sabilitytodemonstratecompliancewithPAS-55.

Recommended Actions

ThatWestpowerconcentratesonimplementationoftheprocessesdefinedinitsoverarchingassetmanagementsystemdocumentation.Attheendoftheperiod,WestpowermustreviewtheperformanceoftheassetandtheassetmanagementsystemforconformancewithPAS-55toenhanceitscontinualimprovementprogram.

ThatWestpowercompletesafullinternalauditagainstPAS-55usingacompetentauditorpriortoendofMarch2013

8.12.2 ReviewagainstPAS55-1

“The organisation shall conduct a review to compare the current management of its assets against therequirementofPAS55-1.”

Table 8.12.1 4.1 - General Requirements

Q# PAS-55 Criteria Score MaturityLevel Comments AMS

Section

4.1.1 Asset Management System

1 aEstablishandmaintainAMSthatconformstoallrequirementsof

PAS55-1.3 Developing

ThedraftAMSisagooddocumentforestab-lishingPAS55intoWestpower.Allelementsneedtobesatisfiedtoreceivefullcompliancescoreforestablishment.Unabletoscoreformaintainasnotfullyimplementedyet.PAS55wasusedin2008asatoolforpracticesreviewandreportedinthe2011AMP.

All

2 b AMSdetailandcomplexityfitsthesizeofthecompany. 4 Compliant ThedraftAMSisanappropriatesizefor

Westpower. All

3 c AMSboundaryiswelldefined. 4 Compliant

TheAMSboundaryisdefinedaselectricitydistributionfortheWestCoast.Therelation-shipwithElectronetisclearlydefinedandthe

linktoWestpowerforPAS55purposes.

2

4 d Aneffectiveoverallsystemdrawingonothercompanysystems. 4 Compliant

TheAMSlinkswelltootherexistingsystemsandthereisgoodlinkstoassociateddocu-

mentsinSection5.Therearelinkstoexistingpoliciesasnotedbelowin4.9.

All




Westpowerhasdevelopedastand-aloneassetmanagementsystemasrequiredbyPAS-55.ThedocumenthasbeenindependentlyreviewedbyAECOMandthegapanalysisispresentedhereinthisAMP.ThegapanalysisrelatesmainlytothedocumentedprocessesbutitstillremainsforWestpowertofullyimplementandreviewtheseprocesses.


Q# PAS-55 Criteria Score Maturity Level Comments AMS Sec-

tion

4.1.2 Review against PAS 55-1

5 a ReviewagainsttheStrategicPlan. 4 CompliantThedraftAMSisalignedwiththeSCIandStrategicPlan,Westpower’smainstrategic

plans.3

6 b Reviewcompliancewithlegislationandregulations. 4 Compliant

ThedraftAMSsummariseslegislativecom-plianceinAMPolicy,StrategyandObjec-tives,Sections4.8,5.8and6.6respectively.

Itisreportedtotheboardquarterly.

4.8,5.8,6.6

7 c Identificationandevaluationofas-setmanagementrisks. 4 Compliant

Ariskmanagementassessmenthasbeencompletedthatcoverslikelyriskevents

includingcriticalassets,operations,futureplanningandenvironmental.Eachidenti-fiedriskisassessedforimpact,effective-nessandlikelihoodratingsresultinginaconsequencesrating.ThisissummarisedindraftAMSSection5.7andtheassociated

documentriskmanagementanalysis.

5.7

0

1

2

3

4

5

6

Esta

blish

an

d m

ain

tain

AM

S th

at co

nfo

rms to

all

req

uire

me

nts

of P

AS

55

-1.

AM

S d

eta

il a

nd

co

mp

lexity fits th

e s

ize

of

the

co

mp

an

y.

AM

S b

ou

nd

ary

is w

ell

de

fin

ed

.

An

effe

ctive

ove

rall

syste

m d

raw

ing

on

oth

er

co

mp

an

y s

yste

ms.

PAS-55 Aligned


Recommended Actions

Thattheassetmanagementsystembefullyimplementedandreviewedwiththeintentionofseekingtoobtainindependentexternalcertificationwithintwoyears,verifyingcompliancewiththedocumentedrequirements.Aninternalauditatthecompletionofthefirstyearwouldprovidequalityguidance.

8.12.3 AssetManagementPolicy

“Theorganisation’stopmanagementshallauthoriseanoverallassetmanagementpolicy.”


Q# PAS-55 Criteria Score Maturity Level Comments AMS Sec-

tion

8 d ExistingAMpracticesandproce-dures. 4 Compliant

Theexistingpracticesaredocumentedwellinthe2011AMP.Thiscouldbestrength-enedwithastatementinSection7AMPaboutthereviewofExistingAMpractices.

ExistingproceduresarestatedinthelinkstoassociateddocumentsintheAM

Strategy.

5,7

9 eReviewtheperformanceofassetsandassetsystem(suitability,utilisa-

tion,conditionandcosts).4 Compliant

Assetmanagementperformanceissum-marisedindraftAMSSection5.2,Reli-

ability.Therestillneedstobealinktothe2011AMP(Section3AssetsCovered).Itisstatedthatoveralltheassetsareingoodconditionbutthereneedstobeastate-mentthatWestpowerwishestoprotectthatposition.Weunderstandthatassetsarestillnotperformingandnotmeeting

thetargets.Thisshouldbeexplicitlystated

5.2

10 f Reviewfeedbackfrompreviousincidentinvestigations. 4 Compliant

Thereviewoffeedbackfrompreviousincidents,accidentsandemergenciesisprovidedinthedraftAMSSection6.1Safetyand16.2InvestigationofFailure,IncidentsandNonconformities.AnAM

ReviewProcesshasbeendevelopedwhichincludesperformanceofincidentinvestiga-

tions,andstartedin2011.

6.1,16.2

11 g Relevantmanagementsystems,competencyandresourcing. 4 Compliant

ThereisaninternalbusinessintelligencesystemTheVaultthatholdstraining

records.WeunderstandthatWestpowerhasaSharepointoperatingthathosts

dedicatedhealthandsafetyinformation,trainingrecordsandincidences.ThereisaformalHealthandSafetyCommittee,stafftrainingprogramsandHazardIdentifica-tionProgramasdetailedinAMStrategy.ThereisalsoadedicatedAssetManage-

mentGroupwithabout14peoplebasedatElectronet,reportingtoWestpower’sAssetManager.ThetrainingforthisgroupisnotcoveredbyTheVaultbutthereisasepa-ratetrainingrecordfortheAMGandthisis

anassociatedocumenttoSection10.

5.1,10




Theintentofrequiringanassetmanagementpolicyistoprovideareferencedocument,endorsedbythemostseniormanagementof thebusiness,defining theboundariesor frameworkwithinwhichassetmanagementdecisionsmustbemadewithintheorganisation.Westpowerhasdevelopedadraftpolicywhichisalignedwiththisrequirement.CompletionandendorsementofthepolicywouldseetheaboveratingsalignwithPAS55.

Table 8.12.3 4.2 - Asset Management Policy

Q# PAS-55 Criteria Score Maturity Level Comments AMS

Section


12 a Consistentwithstrategicplan. 4 Compliant

ThepolicyisbasedonWestpower’sSCI(dated2011-2013)andtheStrategicPlan(dated30September

2010).Thesearetheirmainstartegicplans.4

13 bAppropriateinnatureandscaleoforganisation’sas-

sets.4 Compliant

ThedraftAMPpolicyisthreepagesinlengthwhichisappropriateformostpoliciesandconsideringWest-

powerisarelativelysmallEDB.4

14 c Consistentwithotherpoli-cies. 4 Compliant

ThealignmentwithotherpoliciesissummarisedindraftAMSSection4.9includingtheMaintenanceandOperationPolicy,andhealthandsafety.TherearelinkstootherpoliceslistedattheendofAMSSection4.9.Itwouldbedesirabletohaveaseparateenvironment

policy.

4.9

15 dConsistentwithorganisa-tion’soverallriskmanage-

mentframework.4 Compliant ThisisadequatelyaddressedinAMSSection4.7. 4.7

0

1

2

3

4

5

6

Co

nsis

ten

t w

ith

str

ate

gic

pla

n.

Ap

pro

pria

te in

na

ture

an

d

sca

le o

f o

rga

nis

atio

n’s

asse

ts.

Co

nsis

ten

t w

ith

oth

er

po

licie

s.

Co

nsis

ten

t w

ith

org

an

isa

tio

n’s

ove

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isk

ma

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ge

me

nt fr

am

ew

ork

.

Fra

me

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rk e

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s A

M

str

ate

gy, o

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s a

nd

pla

ns to

be

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Co

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le

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Prin

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be

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ch

as h

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en

t to

co

ntin

ua

l

imp

rove

me

nt.

Do

cu

me

nte

d,

imp

lem

en

ted

an

d

ma

inta

ine

d.

Co

mm

un

ica

ted

to

sta

ke

ho

lde

rs

Re

vie

we

d p

erio

dic

ally.

PAS-55 Aligned


Recommended Actions

That the draft asset management policy is formally endorsed by directors and the matter recorded in thecompanyminutes

• Thattheapprovaldateandauthorityberecordedonthepolicystatement;

• Thatthepolicybeformallycommunicatedthroughouttheorganisation;

• Setareviewcycle;itissuggestedthatthiscoincidewithfinalisationoftheSCIorotherstrategicplanningdocuments;

8.12.4 AssetManagementStrategy

“Theorganisationshallestablish,document,implementandmaintainalong-termassetmanagementstrategyauthorisedbytopmanagement.”

Table 8.12.3 4.2 - Asset Management Policy


Section

16 eFrameworkenablesAMstrategy,objectivesandplanstobeimplemented.

4 Compliant

TheAMPolicyinSection4setstheframeworkfortheAMstrategy,andobjectiveswell.Weunderstandthattherearemultiplesourcesofworkneedsthatarenotwelllinkedtothefinancialpoliciesandbudgets.Frequentlytheplannedcapitalworksprogrammesarenotdelivered.Thereneedstobecontrolsandconse-quencesfornotdeliveringtheplannedprogramme.ThiswouldbebettercoveredinSection15Implemen-

tationofAMPs.

4

17 f Commitmenttocomplywithlegislation. 4 Compliant

ThisisaddressedadequatelyinAMSSection4.8althoughbrieflyandnowstatesthekeylegislation

suchasHealthandSafetyinEmploymentActandtheElectricityAct.

4.8

18 g

Principlestobeappliedsuchashealthandsafety,andsustainabledevelop-

ment.

4 Compliant

Thisisaddressedadequatelyforhealthandsafety,andsustainabilityinAMSSections4.1and4.4respectively.Moredepthtohealthandsafetyprincipleswouldbe

helpful.

4.1,4.4

19 h Commitmenttocontinualimprovement. 4 Compliant Thisisaddressedadequatelyundercontinualimprove-

mentinAMSSection4.4. 4.4

20 i Documented,implementedandmaintained. 3 Develop-

ing

TheAMPolicyisdocumentedasprovidedinAMSSec-tion4.ThereisaformalreviewnowasstatedindraftAMSSection4.10.Unabletoscoreformaintainasnot

fullyimplementedyet.

4.4,4.10

21 j Communicatedtostake-holders 4 Compliant

CommunicationwithstakeholdersissummarisedinAMSSection4.4SustainableunderCommunication.Thisissupportedbyanassociateddocumentshow-ingthekeystakeholdersandtheirinterestarea.ThepolicyiswritteninplainEnglishandiseasytoreadsoprovidesagoodplatformforcommunicationwithstakeholders.Itisimportantthatthereistopmanage-mentendorsementassuggestedwithCEOsignature

thatisvisibletostaffandserviceproviders.Weunder-standthattheAMSwillbeavailableontheintranet.

4.3,4.4

22 k Reviewedperiodically. 4 CompliantThereisastatementonannualreviewinAMSSection4.4asdiscussedabove.ThereviewhistorywillbeshowninSection4.10aftereveryannualreview.

4.4,4.10




In thePAS-55context, asset strategies refer to theoverall approach tomanaginganasset class i.e.defininghowtheasset is tobemanaged,sothatdetailedoperationalplans for individualassetscanbederived.TheWestpowerassetmanagementsystemcontainsadescriptionofassetstrategiesbyassetclass.Improvementscouldbemadebylinkingassetstrategiestoariskmanagementprocess.

Table 8.12.4 4.3 - Asset Management Strategy, Objectives and Plans


Section


23 aConsistentwithpolicyandorganisationalstrategicplan.

4 Compliant ThisisaddressedintheintroductionparagraphatthestartofAMSSection5. 5

24 bConsistentwithotherorganisationalpolicies

andstrategies.4 Compliant

Therearegoodlinkstoassociateddocumentsattheendofeachstrategysection,althoughmostofthesedocumentsarenotstrategiesorpolicies.ThestrategyisconsistentwiththeAMSpolicywiththesamefor-mat.ItwouldusefultoshownhowtheMaintenanceandOperationsPolicyrelatestotheAMStrategy,

especiallySection5.2Reliability.

5

0

1

2

3

4

5

6

Co

nsis

ten

t w

ith

po

licy a

nd

org

an

isa

tio

na

l str

ate

gic

pla

n.

Co

nsis

ten

t w

ith

oth

er

org

an

isa

tio

na

l p

olicie

s a

nd

str

ate

gie

s.

Co

nsid

ers

sta

ke

ho

lde

r re

qu

ire

me

nts

.

Life

cycle

ma

na

ge

me

nt

req

uir

em

en

ts o

f a

sse

ts.

Asse

t re

late

d r

isks,

an

d a

sse

t a

nd

asse

t syste

m

cri

tica

litie

s.

Ide

ntifie

s t

he

fu

nctio

n,

pe

rfo

rma

nce

an

d c

on

ditio

n o

f

exis

tin

g a

nd

cri

tica

l a

sse

ts.

Sta

te f

utu

re f

un

ctio

n,

pe

rfo

rma

nce

an

d c

on

ditio

n.

Cle

arl

y s

tate

s p

rin

cip

le m

eth

od

s o

f a

sse

t

ma

na

ge

me

nt.

Pro

vid

es s

uff

icie

nt

gu

ida

nce

fo

r A

M o

bje

ctive

s a

nd

AM

P t

o b

e p

rod

uce

d.

Cri

teri

a f

or

op

tim

isin

g A

M o

bje

ctive

s a

nd

pla

ns.

Co

mm

un

ica

ted

to

sta

ke

ho

lde

rs A

M s

tra

teg

y r

ela

ted

ob

lig

atio

ns.

Re

vie

we

d p

eri

od

ica

lly f

or

eff

ective

ne

ss

PAS-55 Aligned




Section

25 c Considersstakeholderrequirements. 4 Compliant

Thereisconsiderationofstakeholderrequirementsasfollows:1.Thereisageneralstatementaboutcommunicatingwithcon-tractorsandpublicattheendofSection5.1,Safe-

ty.2.ThereisageneralstatementaboutsurveyingconsumersonaregularbasisandacustomercomplaintsysteminSection5.2.3.ThereisageneralstatementaboutdiscussionswithTranspowerinSection5.3Security.4.Thereisageneralstatementaboutcommunicat-ingwiththeBoardaboutoilspillsinSection5.6EnvironmentalImpact.5.Thereisageneralstatementaboutdiscussion

withstakeholdersontheAMSattheendofAMSSection5.8,CompliancewithLegislation.ThereisgoodinformationabouttwoindustrygroupsENAandEEAthatWestpowerparticipateswith.

6.ThedraftAMSSection5.9summarisescommuni-cationwithstakeholders.Thisincludesalinktothe

Westpowerstakeholdermatrix.

5.1,5.2,5.3,5.6,5.8,5.9

26 d Lifecyclemanagementrequirementsofassets. 4 Compliant

AMSSection5.4SustainabilityprovidesastatementaboutassetlifecyclemanagementwithareferencetoSection6oftheAMP.Itcouldbestrengthenedby

identifyingthekeyassetissuesforWestpower.

5.4

27 eAssetrelatedrisks,andassetandassetsystem

criticalities.4 Compliant

AMSSection5.7detailstheriskprocessesWestpowerundertakeswithfiveassociateddocuments.Assetriskiscoveredundertheregularinspectionandthedesignstandardsinplace.ItisalsocoveredwithassetriskmanagementassessmentsummarisedinSection5.7withdetailinRiskManagementAnalysisandProcess.CriticalassetsaresummarisedinAMSSection5.7with

detailintheRiskManagementAnalysis.

5.7

28 f

Identifiesthefunction,performanceandcondi-

tionofexistingandcriticalassets.

4 Compliant

TheassessmentofperformanceandconditionofexistingandcriticalassetsiscoveredinAMSSection

5.2Reliability.Performanceisdiscussedatahighlevelbutdoesnotcovercriticalassetsasrequired.We

suggestthatthereisdetailontheactualperformanceofthecriticalassets.Referencescanbemadeto

therelevantAMPsectionsothereisnorepetitionofmaterial.Thereisgooddiscussiononassetcondition

oftheexistingandcriticalassets.

5.2

29 gStatefuturefunction,

performanceandcondi-tion.

4 Compliant

Thedesiredfuturefunction,performanceandcondi-tionoftheexistingandcriticalassetsissummarisedinAMSSection5.2Reliability.Thisincludesastatementthatyourcustomersaresatisfiedwiththecurrentas-setperformancefromrecentsurveysanddonotwishtheircoststoincrease.Assetperformanceismea-

suredbySAIDIandSAIFIwhichisconsistentwithyourStrategicPlan(forSAIDI).

5.2


Recommended Actions

ThatWestpowercontinue itsdevelopmentofa formal riskmanagementsystemwhichprovides input totheassetstrategyprocess(seelaterrecommendations).

Document responsibility and target timeframes for implementation of the asset management strategy (forexampleanannualassetplanningcalendar)forthedevelopmentofdetailedoperationalplans.

8.12.5 AssetManagementObjectives

“The organisation shall establish and maintain documented asset management objectives which shall bemeasureable,consistentwiththestrategy,communicatedtostakeholdersandperiodicallyreviewed.”



Section

30 hClearlystatesprinciplemethodsofassetman-

agement.4 Compliant

Thestrategyprovidestheprinciplesforas-setmanagementinsomeareasandisweakin

otherareasasfollows:Se-curityofsupplyprinciplesarediscussedadequatelyinAMSSection5.3Security.Thefourwellbeingsarediscussedad-

equatelyinAMSSection5.4Sustainability.Riskmanagementprinciplesaredis-cussedadequatelyinAMSSection5.7.

WholeoflifecostingsisstatedinAMSSections5.4Sustainability.

5.3,5.4,5.7

31 i

ProvidessufficientguidanceforAMobjec-tivesandAMPtobe

produced.

4 CompliantThereisguidanceatquitehighlevelincludingsecurityprogrammessuchasTranspower’sWCGUPandregu-

larequipmentinspectionprogramme.5.3,5.7

32 jCriteriaforoptimis-

ingAMobjectivesandplans.

4 Compliant

TheoptimisationandprioritisationofAMobjectivesandplansissummarisedindraftAMSection5.4.

ThisismonitoredwiththeAMSReviewProcess.Thisshouldbeaddedformallyasanassociatedocument.

5.4

33 kCommunicatedtostake-holdersAMstrategyrelatedobligations.

4 Compliant

CommunicationwithstakeholdersissummarisedinAMStrategySection5aboutawarenessoftheirstrat-egyrelatedobligations.AMSSection5.1statesthattherearespecificforumswherestaffobligationsarediscussedattoolboxmeetingswiththeCEO.Thereisaspecificsectiononcommunicationwithstakehold-

ers,Section5.9.

5.1,5.8,5.9

34 l Reviewedperiodicallyforeffectiveness 4 Compliant ThereviewprocessforthestrategyisstatedinSection

5.10.ItisreviewedDecembereachyear. 17




The intent of this requirement is that the assetmanagement organisation identifies a small number of keyassetmanagementobjectivesthatsetthedirectionforthedetailedplanningprocess.Thesecouldbehighleveldirection statements regarding asset performance, asset creation/replacement, safety and risk and financialperformance.

0

1

2

3

4

5

6

Ob

jective

s a

re

me

asu

rea

ble

.

Ob

jective

s a

re c

on

sis

ten

t

with

AM

Str

ate

gy.

Ob

jective

s a

re c

on

sis

ten

t

with

co

ntin

ua

l

imp

rove

me

nt.

Ob

jective

s a

re

co

mm

un

ica

ted

to

all

rele

va

nt

sta

ke

ho

lde

rs.

Ob

jective

s a

re

pe

rio

dic

ally r

evie

we

d.

Ob

jective

s c

on

sid

er

leg

al, r

eg

ula

tory

an

d

sta

tuto

ry r

eq

uir

em

en

ts.

Ob

jective

s t

ake

acco

un

t

of

the

exp

ecta

tio

ns o

f

sta

ke

ho

lde

rs a

nd

fin

an

cia

l, o

pe

ratio

na

l a

nd

bu

sin

ess r

eq

uir

em

en

ts.

Ob

jective

s t

ake

acco

un

t

of

asse

t m

an

ag

em

en

t

risk.

Ob

jective

s c

on

sid

er

imp

rove

me

nt

op

po

rtu

nitie

s,

inclu

din

g

ne

w t

ech

no

log

ies,

AM

too

ls a

nd

pra

ctice

s.

PAS-55 Aligned

Table 8.12.5 4.3 - Asset Management Strategy, Objective and Plans


Section


35 a Objectivesaremea-sureable. 4 Compliant

Theobjectivesaresummarisedundereachstrategyareainbulletpointformatwithgoodlinkstoassociateddocuments.Theobjectivemeasuresforeachareaarelisted,relevantforWestpower,andcurrentlymeasured.Itwouldbehelpfuliftheobjectiveswerestatedinmea-surabletermsforeachobjective.Someareandsome

arejustreferenced.ThePAS55exampleis:Toachieveanaverageof97%systemavailabilityontheroute.Optimi-sationbetweenperformance,condition,costandriskis

addressedatahighlevelunderSustainability.

6,6.1,6.2,6.3,6.4,6.5,6.7,6.8

36 bObjectivesare

consistentwithAMStrategy.

4 Compliant Theobjectivesarelinkedtoeachstrategy,iesafety,reli-ability. 6

37 cObjectivesarecon-sistentwithcontinual

improvement.3 Develop-

ing

TheobjectivesarereviewedannuallyasstatedinSection6.11.ThiscouldbestrengthenedwithastatementthatthiscontinualimprovementisundertakenwiththeAMP

updateintheLOSsectioneveryyear.

6.11


Westpowerhasanumberofobjectivespublishedintheassetmanagementplan(levelsofservicesection)andin the SCI thatmeet the intentof providingbroadobjectives that canbe furtherbrokendown into specificoperational targets and plans. Westpower’s asset management system clearly and concisely identifies anddocumentskeyassetmanagementobjectivesflowingdirectlyfromthecorporatestrategy.

Recommended Actions

That Westpower further develops key asset management objectives and clearly communicates these withstakeholders.Ensure thatwhendevelopingobjectives thatall requirementsofPAS-5514.3.2are taken intoconsiderationanddocumented.

8.12.6 AssetManagementPlans

“Theorganisationshallestablish,documentandmaintainAMPstorachievetheassetmanagementstrategyanddelivertheobjectivesacrossthelifecycleactivities.”



Section

38 dObjectivesarecom-municatedtoall

relevantstakeholders.3 Develop-

ing

Communicationoftheobjectivestoallrelevantstake-holdersisstatedinAMSSection6.9.Itisstatedthatcommunicationhasbeenlimitedtodatebuttherearefutureplans.Thiscriterionisscoredasdevelopinguntil

theseareimplemented.

6.9

39 e Objectivesareperi-odicallyreviewed. 4 Compliant TheobjectivesarereviewedannuallyasstatedinSection

6.11. 6.11

40 f

Objectivesconsiderlegal,regulatoryandstatutoryrequire-

ments.

4 CompliantAMSSection6.7summariseslegislativecompliance.Itisnotedthatacompliancereportwillbeaddedasan

associatedocument.6.7

41 g

Objectivestakeac-countoftheexpecta-tionsofstakeholdersandfinancial,opera-tionalandbusiness

requirements.

4 Compliant

Stakeholdersandfinancial,operationalandbusinessrequirementsareconsideredunderReliability,Security,SustainabilityandCostefficiencyObjectives.ThesearereportedtostakeholderthroughInformationDisclosure.

6.2,6.3,6.4,6.5

42 hObjectivestake

accountofassetman-agementrisk.

4 CompliantRiskmanagementobjectivesaresummarisedinAMSSection6.6includingthemanagementofrisk,critical

assetsandemergencyplanning.

6.1,6.2,6.3,6.6,

6.7

43 i

Objectivesconsiderimprovementop-

portunities,includingnewtechnologies,AMtoolsandprac-

tices.

4 Compliant AMSSection6.10summarisesimprovementopportuni-tieswithcurrentinitiatives. 6.1




While it is almost certain that activities areoptimisedandprioritisedby theassetmanagement teamusingcollectiveexperience,Westpowershouldconsiderimplementingaformalprojectranking/prioritisationschemeincorporatingtheriskmanagementmethodology.Suchanapproachcouldbeofassistanceinmanaginganygapbetweenavailablefunds/resourcesandproposedprojects. ItwasnotapparentfromthematerialpresentedthatWestpowerclearlyallocatesaccountabilitytoindividualsforallassetmanagementobjectivesoroutcomes,ifthisisthecasethenclearbenefitscanbeobtainedbyclarifyingthispoint.Alsonotapparentfrommaterialprovidedisaprocesstoclearlycontrolandmanageprojecttimingandcosts.

0

1

2

3

4

5

6A

MP

sp

ecifie

s t

asks a

nd

activitie

s r

eq

uir

ed

to

op

tim

ise

co

st,

ris

k a

nd

pe

rfo

rma

nce

.

AM

P d

esig

na

tes

resp

on

sib

ilitie

s a

nd

au

tho

ritie

s f

or

the

ach

ieve

me

nts

of

AM

ob

jective

s.

AM

P p

rovid

es t

he

me

an

s

an

d t

ime

sca

les f

or

actio

ns

to b

e a

ch

ieve

d.

PAS-55 Aligned


Q# PAS-55 Criteria Score MaturityLevel Comments AMP

Section


44 aAMPspecifiestasksandac-tivitiesrequiredtooptimisecost,riskandperformance.

4 Compli-ant

TheoptimisationofcostandriskisstatedinAMSSection7withgoodreferencingtotheAMP.As-setperformanceisdiscussedwellindraftAMS

Section7,supportedwithgoodreferencingtotheAMP.

7

45 b

AMPdesignatesresponsi-bilitiesandauthoritiesfortheachievementsofAM

objectives.

4 Compli-ant

TheresponsibilitiesandauthoritiesfortheachievementofAMobjectivesarecoveredinthedraftAMSSection7byWestpower’sAssetMan-agerwithsupportfromElectroNetServiceLtd.

7

46 cAMPprovidesthemeansandtimescalesforactions

tobeachieved.4 Compli-

ant

ThedevelopmentoftheworkplanisdiscussedwellindraftAMSSection7,supportedwithgood

referencingtotheAMP.7


Recommended Actions

ThatWestpower implement amethodology for ranking/rating assetmanagement initiatives to assist in theoptimisation,anddocumentationoftheoptimisationprocess.

ThatWestpowerconfirmsthatithasinplaceadetailedprogrammeofworkdefiningprojectsandinspectionandmaintenanceprogrammes.Theprogrammeshouldallocateaccountabilityforoutcomes,targetdates,andbudgets.Theprogramshouldbesupportedbyarobustprocessformonitoringdelivery,quality,safetyandcost.Thisisdrivenfurtherininformationdisclosurerequirements2008.

8.12.7 ContingencyPlanning

“The organisation shall establish, implement andmaintain appropriate plans and procedures for identifyingandrespondingtoincidentsandemergencysituationsandmaintainingthecontinuityofcriticalmanagementactivities.”



PAS-55requiresthatcredibleemergencyscenariosareconsideredandthatcontingencyplanningisinplace.

0

1

2

3

4

5

6

Co

ntin

uity p

lan

co

nsid

ers

asse

t re

late

d r

isk.

Co

ntin

uity p

lan

co

nsid

ers

po

ten

tia

l d

isru

ptio

n to

th

e

critica

l A

M a

ctivitie

s.

Co

ntin

uity p

lan

co

nsid

ers

the

mo

st a

pp

rop

ria

te

resp

on

se

actio

ns.

Co

ntin

uity p

lan

co

nsid

ers

the

co

mp

ete

ncy a

nd

tra

inin

g o

f p

ers

on

ne

l.

Co

ntin

uity p

lan

co

nsid

ers

the

ne

ed

s o

f th

e

sta

ke

ho

lde

rs a

ffe

cte

d b

y

the

em

erg

en

cy.

PAS-55 Aligned


Recommended Action

Thatthecontingencyplanscurrentlyinplacebeformallyreviewedanddocumentedforeffectiveness.

8.12.8 ContingencyPlanningInformation

“The plans and procedures shall identify how the organisationwill respond to, andmanage, incidents andemergencysituations.”



Section

4.3.4 Contingency Planning

47 a Continuityplanconsidersassetrelatedrisk. 4 Compli-

ant

ThedraftAMSSection8ontheContingencyPlanningsummarisesWestpower’scontingencyplanning.TheEmergencyResponsePlan(ERP)islistedasanassociateddocument.AssetrelatedriskisdetailedindraftAMSSection8.1whichis

mainlyfocusedonTranspower’sGXPs.

8.1

48 bContinuityplanconsiderspotentialdisruptiontothe

criticalAMactivities.4 Compli-

ant

ThedraftAMSSection8.1considersdisruptiontocriticalAMactivitiesespeciallyGXPsandCBD

areas.8.1

49 cContinuityplanconsid-ersthemostappropriate

responseactions.4 Compli-

antResponseactionsarecoveredindraftAMSSec-tion8.3andintheERP,Section4Planning. 8.3

50 dContinuityplanconsiders

thecompetencyandtrainingofpersonnel.

4 Compli-ant

ThecompetencyandtrainingofpersonnelinanemergencyresponseissummarisedindraftAMSSection8.4.Thelinktoothersectionsshouldbe

stated,ieSection10.

8.4

51 e

Continuityplanconsiderstheneedsofthestakehold-ersaffectedbytheemer-

gency.

4 Compli-ant

StakeholderneedsaresummarisedindraftAMSSection8.5withtheemergencycontactlist.ThereisalsoastatementaboutCivilDefence

EmergencyManagement(CDEM)requirementsasalifelineutility.

8.3




PAS-55requiresthatcredibleemergencyresponsesareconsideredandthatcontingencyplanninginformationisinplace.

0

1

2

3

4

5

6

Co

ntin

uity p

lan

in

clu

de

s

info

rma

tio

n o

n e

sse

ntia

l

pe

rso

nn

el.

Arr

an

ge

me

nts

fo

r in

tern

al

an

d e

xte

rna

l

co

mm

un

ica

tio

n.

Ma

inta

in o

r re

sto

re its

cri

tica

l A

M a

ctivitie

s.

Pro

vis

ion

of

ne

ce

ssa

ry

reso

urc

es r

eq

uir

ed

du

rin

g

an

in

cid

en

t.

Re

co

rdin

g o

f e

sse

ntia

l

info

rma

tio

n.

Pro

ce

ss f

or

retu

rnin

g t

o

no

rma

l o

pe

ratio

n.

PAS-55 Aligned



Section


52 1Continuityplanincludesinformationonessential

personnel.4 Compli-

ant

TheSummaryBCPshowstheorganisationstruc-tureanddesignatedstaffdetailsinSection3ERPwithcontactlistinAnnexE.Itisalsosummarised

indraftAMSSection8.1.

8.1

53 2Arrangementsforinternalandexternalcommunica-

tion.4 Compli-

antInternalandexternalcommunicationisprovided

inERPSection5.6. 8

54 3 Maintainorrestoreitscriti-calAMactivities. 4 Compli-

ant

RestorationofcriticalAMactivitiesisprovidedinERPSection4andindraftAMSSection8.1with

mobilesubstation.8.1

55 4Provisionofnecessary

resourcesrequiredduringanincident.

4 Compli-ant

RequiredresourcesareprovidedinERPSection3andAnnexEforpersonnel,internalitemsinAnnexD,andexternalitemsandpersonnelinAnnexF.

8

56 5 Recordingofessentialinfor-mation. 4 Compli-

ant EssentialinformationisprovidedinERPAnnexB. 8


Recommended Action

Thatthecontingencyplanninginformationcurrentlyinplacebereviewedforeffectiveness.

8.12.9 Structure,AuthorityandResponsibility

“Theorganisationshallestablishandmaintainanorganisationalstructureofroles,responsibilitiesandauthoritiesconsistentwiththeachievementofitsassetmanagementpolicystrategy,objectivesandplans.”



Westpower has an appropriate organisational structure within which to implement an effective assetmanagementsystem.Areasforimprovementarecentredonimplementationofpolicyandstrategydocumentsandaneffectiveriskmanagementsystem.

0

1

2

3

4

5

6

Ap

po

intin

g a

me

mb

er

of

top

ma

na

ge

me

nt

for

resp

on

sib

ility o

f th

e A

MS

.

Ap

po

int

me

mb

ers

of

ma

na

ge

me

nt

for

resp

on

sib

ility o

f

the

AM

S d

elive

ry.

Org

an

isa

tio

n id

en

tifie

s a

nd

mo

nito

rs t

he

exp

ecta

tio

ns

of

sta

ke

ho

lde

rs.

En

su

re t

he

po

licy a

nd

str

ate

gy is c

on

sis

ten

t w

ith

th

e

org

an

isa

tio

na

l str

ate

gic

pla

n.

Co

nsid

ers

ad

ve

rse

eff

ects

th

e A

MS

mig

ht

ha

ve

on

oth

er

asp

ects

.

Co

nsid

er

the

via

bility o

f th

e A

MS

.

Asse

t re

late

d r

isks a

re id

en

tifie

d a

nd

in

clu

de

d o

n

org

an

isa

tio

na

l ri

sk f

ram

ew

ork

.

En

su

re a

va

ila

bility o

f su

ffic

ien

t re

so

urc

es.

Co

mm

un

ica

te t

o a

ll r

ele

va

nt

sta

ke

ho

lde

rs t

he

imp

ort

an

ce

of

co

mp

lyin

g w

ith

th

e r

eq

uir

em

en

ts o

f A

MS

in o

rde

r to

ach

ieve

its

org

an

isa

tio

na

l str

ate

gic

pla

n.

PAS-55 Aligned



Section

57 6 Processforreturningtonormaloperation. 4 Compli-

ant

ProcessforreturningtonormaloperationisprovidedinERPSection4andindraftAMSSection

8.3.8.3


Recommended Actions

• Implementriskmanagementmethodology.Inadditiontoassetrelatedrisks, includesomeassessmentofintangibleriskssuchasreputation,staffmoraleetc.

• Consider benefits of providing a regular summary risk report to senior management and board forconsideration.Thisshouldformpartoftherecommendedriskmanagementprocess.

• EnsurethatmanagementcommunicatestheimportanceofdeliveringAMPs(e.g.workprograms)toachievetheorganisationsgoals.

• Improvecommunicationthroughouttheorganisationoftheassetmanagementstrategyandpolicy.

Table 8.12.9 4.4 - Asset Management Enablers and Controls

Q# PAS-55 Criteria ScoreMa-

turity Level

Comments AMS Section

4.4.1 Structure, Authority and Responsibilities

58 aAppointingamemberoftopmanagementforresponsibil-

ityoftheAMS.4 Compli-

ant

AMSresponsibilityisWestpower’sAssetManagerwithsupportfromElectroNetServiceLtdasde-tailedindraftAMSSections2and9.Werecom-mendthatthePAS55requirementsatthestartofSection9beremovedasitisunnecessary.Also

removethesecondorganisationstructure.

2,9

59 bAppointmembersofman-

agementforresponsibilityoftheAMSdelivery.

4 Compli-ant

AMSresponsibilityissupportedwithElectroNetServiceLtdasdetailedindraftAMSSections2and

9.2,9

60 cOrganisationidentifiesandmonitorstheexpectationsof

stakeholders.4 Compli-

ant

StakeholderexpectationsaresummarisedinAMSSection9includingastatementontheindepen-dentsurveyofstakeholderseverytwoyears.TheConsumerEngagementResultsislinkedasanas-

sociateddocument.

5,9

61 dEnsurethepolicyandstrat-egyisconsistentwiththe

organisationalstrategicplan.4 Compli-

ant

ThepolicyandstrategyarealignedwiththeSCIthroughthesamecategoriesanddirectionsetbytheSCI.DraftAMSSection9statesthatthe

achievementofthestrategicplaniscommunicatedwithstakeholders.

3,4,5,9

62 eConsidersadverseeffectstheAMSmighthaveon

otheraspects.4 Compli-

antAgapanalysistoolisusedtomanagetheadverse

effectscreatedbytheAMS. 9

63 f ConsidertheviabilityoftheAMS. 4 Compli-

ant

TheviabilityofthisAMSwillbedependentonitsreviewtoensureitisaliveandusefuldocument.TheAMSiscontrolledbytheAssetManagerasstatedinAMSSection2withresourcesfromtheAssetManagementGroup(AMG)asstatedinSec-

tion9.

2,9

64 gAssetrelatedrisksareidenti-fiedandincludedonorgani-sationalriskframework.

4 Compli-ant

Theprocessandframeworkforassetriskassess-mentissummarisedindraftAMSSection9. 5.7,9

65 h Ensureavailabilityofsuf-ficientresources. 4 Compli-

ant

TherearesufficientresourceswiththeAMGledbytheAssetManagerasstatedindraftAMSSections

2and9.2,9

66 i

Communicatetoallrelevantstakeholderstheimportanceofcomplyingwiththere-

quirementsofAMSinordertoachieveitsorganisational

strategicplan.

4 Compli-ant

Thecommunicationtostakeholdersandtheimpor-tanceofcomplyingwiththerequirementsofAMSarediscussedinSections9and11.Themainfor-malcommunicationiswiththeWestCoastElectric

PowerTrustsupportedbyconsumersurvey.

9,11


8.12.10OutsourcingofAssetManagementActivities

“Whereassetmanagementactivitiesareoutsourcedtheorganisationshallensurecontroloversuchaspects.”



Westpowerhas outsourced its assetmanagement activities to ElectroNet Services Limited (100%ownedbyWestpower)andWestpower’sGeneralManager,AssetsandEngineeringServicesheadstheassetmanagementgroupinElectroNet.ThisstructureensuresthatcontroloftheassetmanagementactivitiesremainfirmlywithWestpower.

0

1

2

3

4

5

6

Org

an

isa

tio

n id

en

tifie

s a

nd

do

cu

me

nts

th

e p

roce

ss

an

d a

ctivitie

s t

o b

e

ou

tso

urc

ed

.

Org

an

isa

tio

n id

en

tifie

s a

nd

do

cu

me

nts

th

e p

roce

ss

an

d s

co

pe

fo

r sh

ari

ng

of

kn

ow

led

ge

an

d

info

rma

tio

n.

Org

an

isa

tio

n id

en

tifie

s a

nd

do

cu

me

nts

th

e a

uth

ori

tie

s

an

d r

esp

on

sib

ilitie

s w

ith

in

the

org

an

isa

tio

n f

or

ma

na

gin

g t

he

ou

tso

urc

ed

pro

ce

sse

s a

nd

activitie

s.

PAS-55 Aligned


Q# PAS-55 Criteria Score MaturityLevel Comments AMSSec-

tion

4.4.2 Outsourcing of Asset Management Activities

67 aOrganisationidentifiesanddocumentstheprocessandactivitiestobeoutsourced.

4 Compli-ant

TheoutsourcedAMGatElectronetledbyWest-power’sAssetManagerisstatedinAMSSections

2and9.2,9

68 b

Organisationidentifiesanddocumentstheprocessandscopeforsharingofknowl-

edgeandinformation.

4 Compli-ant

WestpowerhasSharePointandTheVaultwheremostinformationisstoredandaccessedasstatedindraftAMSection9.TheAMGislocatedintheGreymouthWestpowerofficesasstatedinSec-

tions9and11.

2,9

69 c

Organisationidentifiesanddocumentstheauthoritiesandresponsibilitieswithintheorganisationformanag-ingtheoutsourcedprocess-

esandactivities.

4 Compli-ant

Theauthorityandresponsibilitywithintheorgani-sationformanagingtheoutsourcedprocessesandactivitiesisclearlyassignedtoWestpower’sAsset

ManagerasstatedinAMSSections2and9.

10


Recommended Actions

• Thatdiscussionsbetweenthetwopartiesarefullydocumentedandperiodicallyreviewedforeffectiveness.

8.12.11Training,AwarenessandCompetence

“Theorganisationshallensurethatpersonnelunderitsdirectcontrolundertakingassetmanagementrelatedactivitieshaveanappropriatelevelofcompetenceintermsofeducation,trainingorexperience.”



Theintentofthisgroupofrequirementsistoensurethatpersonnelinvolvedintheassetmanagementsystemhavetheappropriateskillsandcompetenciesnecessarytooperateallaspectsoftheassetmanagementsystem.

0

1

2

3

4

5

6

Pro

ce

sse

s fo

r p

ers

on

ne

l

to b

e a

wa

re o

f a

sse

t

rela

ted

ris

ks.

Pro

ce

sse

s fo

r p

ers

on

ne

l

to b

e a

wa

re o

f th

e

imp

ort

an

ce

of co

mp

lyin

g

with

th

e A

MS

.

Pro

ce

sse

s fo

r p

ers

on

ne

l

to b

e a

wa

re o

f th

e

co

nse

qu

en

ce

s o

f

de

pa

rtu

re fro

m th

e A

MS

.

PAS-55 Aligned



Section

4.4.3 Training, Awareness and Competence

70 aProcessesforpersonneltobeawareofassetrelated

risks.4 Compli-

ant

AMSSection10detailsthestafftraininginassetmanagement.Thesearediscussedatregular

meetings.Weareunabletoverifyifthisiscorrectwithadesktopreviewonly.

10

71 bProcessesforpersonneltobeawareoftheimportanceofcomplyingwiththeAMS.

4 Compli-ant

AMSSection10detailstheAssetManagementGroupwhichisresponsibleforensuringthatallpersonnelunderstandtheimportanceofcomply-ingwiththeAMS.Again,weareunabletoverifyif

thisiscorrectwithadesktopreviewonly.

10


Recommended Actions

• Identifypolicies,proceduresandrequirementsthatarerelevanttoeachpartoftheorganisation.

• Implementaprogramofprocess/procedurediscussionandreview.Ensurethatdiscussionscoverindividual’srolesandresponsibilitiesandthatrecordsarekept.

• Ensurethatstaffareawareofwhykeyassetmanagementactivitiesarenecessaryandtheconsequencesofnotperformingtheactivityasrequired.

• Developa longtermskilldevelopmentplantoensurethatkeyskillsareavailabletoWestpower intothelongerterm.

8.12.12Communication,ParticipationandConsultation

“Theorganisation shall ensurepertinent assetmanagement information is effectively communicated to andfromemployeesandotherrelevantstakeholders,includingcontractedserviceproviders.”


0

1

2

3

4

5

6

Co

nsu

lta

tio

n w

ith

sta

ke

ho

lde

rs in

th

e

de

ve

lop

me

nt

of

po

licy,

str

ate

gy a

nd

ob

jective

s.

Co

nsu

lta

tio

n w

ith

sta

ke

ho

lde

rs in

th

e

de

ve

lop

me

nt

of

fun

ctio

na

l

po

licie

s,

sta

nd

ard

s a

nd

pro

ce

sse

s.

Co

nsu

lta

tio

n w

ith

sta

ke

ho

lde

rs in

th

e

asse

ssm

en

t o

f ri

sk a

nd

co

ntr

ols

.

Co

nsu

lta

tio

n w

ith

sta

ke

ho

lde

rs in

th

e

asse

ssm

en

t in

cid

en

t

inve

stig

atio

ns.

Co

nsu

lta

tio

n w

ith

em

plo

ye

es a

nd

re

leva

nt

sta

ke

ho

lde

rs in

th

e

pro

ce

ss o

f co

ntin

ua

l

imp

rove

me

nt

of

AM

S.

PAS-55 Aligned



Section

72 c

Processesforpersonneltobeawareoftheconse-quencesofdeparturefrom

theAMS.

4 Compli-ant

WeeklymeetingsareheldwithmanagementandstaffforstaffawarenessofdeparturefromAMS. 10



WestpowerappearstohaveaconsultationandcommunicationprogramwithrespecttoitsAMP,appropriatetothescaleandscopeofitsassetmanagementbusiness.

Recommended Actions

That communication, participation and consultation be expanded for all aspects of the asset managementsystem,includingthepolicies,strategiesandobjectives.

8.12.13AssetManagementSystemDocumentation

“Theorganisationshallestablish,implementandmaintainup-to-datedocumentationtoensureitsAMScanbeadequatelyunderstood,communicatedandoperated.”



tion

4.4.4 Communication, Participation and Consultation

73 a

Consultationwithstakehold-ersinthedevelopmentofpolicy,strategyandobjec-

tives.

4 Compliant

ThereisformalconsultationwithWestpower’ssingleshareholderWestCoastElectricPowerTrust,theBoard,AMG,Transpowerandmajor

users,asdetailedindraftAMSSection11.Thereisgoodcommunicationwithemployeesand

serviceprovider.

11

74 b

Consultationwithstakehold-ersinthedevelopmentoffunctionalpolicies,stan-dardsandprocesses.

4 CompliantAMGconsultswithstakeholdersinthedevelop-mentoffunctionalpolicesasstatedindraftAMS

Section11.11

75 cConsultationwithstakehold-ersintheassessmentofrisk

andcontrols.4 Compliant

ThereisageneralstatementindraftAMSSec-tion11consultationwithstakeholdersinrisk

management.Thiscouldbestrengthenedwithstakeholderinvolvementontheassessmentofriskandcontrols,particularlyTranspowerand

largeusers.

11

76 dConsultationwithstake-holdersintheassessmentincidentinvestigations.

3 Developing

ThereisnoexplicitstatementindraftAMSSec-tion11ontheconsultationwithstakeholdersintheassessmentofincidentinvestigations.Itisgoodpracticetoinvolvestaffinincidentinvesti-gations.ThisshouldbestateddraftAMSSection

11(orsimilarstatement).

11

77 e

Consultationwithemploy-eesandrelevantstake-holdersintheprocessofcontinualimprovementof

AMS.

4 Compliant

ThediagramindraftAMSSection11showshowtheinformationinteractswithstakeholders.Thisissupportedbyastatementaboutcontinuous

improvement.

11




Westpower’s asset management system provides references to all relevant internal policies and procedures and the document’s language is direct and in line with PAS-55 phraseology. The documentation is held within Sharepoint which provides excellent control.Recommended Actions

ThatwidespreadtrainingisprovidedtoallparticipantsinassetmanagementintheuseofSharepointanditscapabilities.

0

1

2

3

4

5

6

AM

S d

ocu

me

nta

tio

n

inclu

de

s a

fu

ll d

escri

ptio

n

of

AM

S a

nd

re

late

d

do

cu

me

nts

.

AM

S d

ocu

me

nta

tio

n

inclu

de

s a

fu

ll d

escri

ptio

n

of

AM

S p

olicy,

str

ate

gy

an

d o

bje

ctive

s.

AM

S d

ocu

me

nta

tio

n

inclu

de

s a

ll r

ele

va

nt

reco

rds.

PAS-55 Aligned



tion

4.4.5 Asset Management System Documentation

78 a

AMSdocumentationincludesafulldescriptionofAMSandrelateddocu-

ments.

4 Compliant

ThedraftAMSiswellpresentedandeasytoread.Therearegoodlinkstoassociateddocu-mentsattheendofsections.Thereisgood

layoutanditflowswell.ThedraftAMSisnotalargedocumentandisappropriateforWest-

power’sassetsize.

All

79 b

AMSdocumentationincludesafulldescriptionofAMSpolicy,strategyand

objectives.

4 CompliantThedraftAMSincludesthepolicy,strategyandobjectivesinonedocument.Itissummarised

indraftAMSSection12.12

80 c AMSdocumentationin-cludesallrelevantrecords. 4 Compliant

ThesupportingrecordsarekeptinTheVaultandWestpower’sdocumentmanagement

system,Sharepoint.12


8.12.14InformationManagement

“Theorganisationshalldesign,implementandmaintainasystemformanagingassetmanagementinformation.”



Inevaluatingthesecriteria,considerationmustbegiventothesizeandcomplexityofthebusinessandassetbaseandthestrategiesthataretobeusedtomanagetheassets.WestpowerhasintroducedMicrosoftSharepointforinformationmanagement.Thiscreatesdocumentaryevidencetodemonstratecompliancewhereitexists,createajustificationwhereitisdeemedappropriatetonotcollectdata,andidentifyareaswhereimproveddatawouldimproveassetmanagementcapabilityandoutcomes.

0

1

2

3

4

5

6

Ad

eq

ua

cy o

f in

form

atio

n

ap

pro

ve

d b

y a

uth

ori

se

d

pe

rso

nn

el.

Info

rma

tio

n p

eri

od

ica

l

revie

we

d a

nd

su

bje

ct

to

ve

rsio

n c

on

tro

l.

Allo

ca

tio

n o

r a

pp

rop

ria

te

role

s,

resp

on

sib

ilitie

s a

nd

au

tho

ritie

s.

Ob

so

lete

in

form

atio

n

pro

mp

tly r

em

ove

d.

Arc

hiv

al in

form

atio

n

reta

ine

d is id

en

tifie

d.

Info

rma

tio

n s

ecu

re,

ba

cke

d u

p a

nd

ab

le t

o b

e

reco

ve

red

.

PAS-55 Aligned



Section

4.4.6 Information Management

81 aAdequacyofinformationapprovedbyauthorised

personnel.4 Compliant

Overall,thedraftAMSSection13InformationManagementiswellwritten.TheinformationiscontrolledbytheAMGasstatedinthisSection

13.

13

82 bInformationperiodical

reviewedandsubjecttover-sioncontrol.

4 CompliantDocumentversioncontrolisprovidedbyShare-point.Maximomanagesaccuraterecordsfor

worksordersasstatedinSection11.13

83 cAllocationorappropriateroles,responsibilitiesand

authorities.4 Compliant AMGisresponsibleforinformationmanagement

asstatedinthisdraftAMSSection13. 13


Recommended Actions

Sharepointisappropriatesoftwareforinformationmanagementbutitrequiresappropriateroles,responsibilitiesandauthoritiesbeallocatedandpoliciesbeintroducedtodealwithobsoleteandarchivalinformation.

8.12.15RiskManagementMethodology

“The organisation shall establish, implement and maintain documented processes and procedures for theongoingidentificationandassessmentofassetrelatedandassetmanagementrelatedrisks.”


0

1

2

3

4

5

6

Me

tho

do

log

y p

rop

ort

ion

ate

to t

he

le

ve

l o

f ri

sk.

Me

tho

do

log

y p

roa

ctive

with

re

sp

ect

to its

sco

pe

,

na

ture

an

d t

imin

g.

Me

tho

do

log

y a

sse

sse

s

ho

w r

isks c

ha

ng

e o

ve

r

tim

e a

nd

usa

ge

.

Me

tho

do

log

y p

rovid

es t

he

cla

ssific

atio

n o

f ri

sk a

nd

ide

ntifica

tio

n o

f ri

sks t

o b

e

avo

ide

d,

elim

ina

ted

or

co

ntr

olle

d.

Me

tho

do

log

y is c

on

sis

ten

t

with

th

e e

xp

eri

en

ce

an

d

ca

pa

bilitie

s o

f th

e

me

asu

res e

mp

loye

d.

Me

tho

do

log

y p

rovid

es f

or

the

mo

nito

rin

g o

f a

ctio

ns.

PAS-55 Aligned



Section

84 d Obsoleteinformationpromptlyremoved. 4 Compliant TheremovalofobsoleteinformationbyShare-

pointisstatedindraftAMSSection13. 13

85 e Archivalinformationre-tainedisidentified. 4 Compliant

Theprocessforarchivinginformationissum-marisedindraftAMSSection13.Notethatarchivedhasbeenspeltachievedinthefirst

paragraphonpage35.

13

86 f Informationsecure,backedupandabletoberecovered. 4 Compliant Informationsecurityandbackupiswellcovered

indraftAMSSection13. 13



PAS-55recognisesriskmanagementasacriticalfeatureofanoverallassetmanagementsystem,andrequiresa comprehensive process be in place to ensure key risks are identified, appropriately considered and actedon.Westpower at presentmanages asset related risk through several separatemeans including the safetymanagement system, periodic external reviews and informal processes that occur during the routine assetmanagementprocess.WestpowerhasdevelopedanoverarchingriskmanagementstrategyalignedwithAS/NZSISO31000:2008,riskmanagement–principlesandguidelinesthattransparentlygroupassetrelatedrisksforassessmentandtreatment.

Recommended Actions

ThatWestpowerreviewsitsoverarchingriskmanagementprocessbasedupontherequirementsofAS/NZSISO31000:2008,riskmanagement–principlesandguidelines.

8.12.16RiskIdentificationandAssessment

“The identification and assessment of risks shall consider the probability of credible events and theirconsequences.”



Section

4.4.7.2 Risk Management Methodology

87 a Methodologyproportionatetothelevelofrisk. 4 Compliant

Westpowerhasaverysoundandestablishedriskmethodology.AlthoughWestpowerisa

smallEDB,itstillprovidesanessentialservicetotheWestCoastcommunitysothemethodology

isappropriate.

5.7

88 bMethodologyproactivewithrespecttoitsscope,nature

andtiming.4 Compliant

ItisstatedthattheRiskManagementPlanisregularlyupdatedsothiscoversbeingproactive

documenttoaddresschanges.5.7

89 cMethodologyassesseshowriskschangeovertimeand

usage.4 Compliant

TheriskprofileisreviewedannuallythroughtheRiskManagementAnalysissummarisedindraft

AMSSection5.7.5.7

90 d

Methodologyprovidestheclassificationofriskandidentificationofriskstobeavoided,eliminatedor

controlled.

4 Compliant RiskclassificationisprovidedinSection9.2,RiskManagementPlan. 5.7

91 e

Methodologyisconsistentwiththeexperienceand

capabilitiesofthemeasuresemployed.

4 Compliant CurrentcontroleffectivenesswasassessedbyWestpowerstaffwiththeinterviewprocess. 5.7

92 f Methodologyprovidesforthemonitoringofactions. 4 Compliant

TheRiskManagementTeammonitorstheactionsforriskwithratingat40orabove,as

statedintheRiskManagementPlan.5.7




Westpower’sriskmanagementidentifiesandassessestherisksofphysicalfailure,operationalfailureandnaturalenvironmentaleventsbutfurtherimprovementscanbemadeforrisksbeyondthecontroloftheorganisationandotherstakeholderrisks

0

1

2

3

4

5

6

Ide

ntifica

tio

n a

nd

asse

ssm

en

t o

f ri

sk

co

nsid

er

the

ph

ysic

al

failu

re r

isks.

Ide

ntifica

tio

n a

nd

asse

ssm

en

t o

f ri

sk

co

nsid

er

the

op

era

tio

na

l

failu

re r

isks.

Ide

ntifica

tio

n a

nd

asse

ssm

en

t o

f ri

sk

co

nsid

er

the

na

tura

l

en

vir

on

me

nta

l e

ve

nts

.

Ide

ntifica

tio

n a

nd

asse

ssm

en

t o

f ri

sk

co

nsid

er

facto

rs o

uts

ide

the

co

ntr

ol o

f th

e

org

an

isa

tio

n.

Ide

ntifica

tio

n a

nd

asse

ssm

en

t o

f ri

sk

co

nsid

er

sta

ke

ho

lde

r ri

sks

su

ch

as f

ailu

re t

o m

ee

t

reg

ula

tory

pe

rfo

rma

nce

.

Ide

ntifica

tio

n a

nd

asse

ssm

en

t o

f ri

sk

co

nsid

er

risks a

sso

cia

ted

with

diffe

ren

t life

cycle

ph

ase

s o

f th

e a

sse

ts.

PAS-55 Aligned



Section

4.4.7.7 Risk Identification and Assessment

93 aIdentificationandassess-mentofriskconsiderthephysicalfailurerisks.

4 CompliantFunctionalfailureisprovidedinthe2011AMP,Sections3and6.Thedetailedriskassessment

coverstheotherphysicalrisks.5.7

94 bIdentificationandassess-mentofriskconsidertheoperationalfailurerisks.

4 Compliant Operationalrisksarecoveredinthe2011,AMPSection6. 5.7

95 c

Identificationandassess-mentofriskconsiderthenaturalenvironmental

events.

4 Compliant

NaturalenvironmentaleventswereassessedwiththedetailedriskassessmentintheRisk

ManagementPlan.ThisresultedinclimaticandseismicfactorsasthekeyrisksforWestpower.

5.7

96 d

Identificationandassess-mentofriskconsiderfactorsoutsidethecontrolofthe

organisation.

4 Compliant

Theriskfactorsoutsidethecontroloftheorganisationwereassessedaspartofdetailedriskassessmentincludingnewtechnologies,

exchangerate,andearthquakes.

5.7


Recommended Actions

ThatWestpowerimplementanoverarchingriskmanagementprocessbasedupontherequirementsofPAS-551andAS/NZSISO31000:2008,RiskManagement–PrinciplesandGuidelines.

8.12.17UseandMaintenanceofAssetRiskInformation

“The organisation shall ensure the results of risk assessments and the effects of risk controlmeasures areconsidered.”


0

1

2

3

4

5

6

Re

su

lts o

f ri

sk a

sse

ssm

en

t

pro

vid

e in

pu

t in

to t

he

str

ate

gy.

Re

su

lts o

f ri

sk a

sse

ssm

en

t

pro

vid

e in

pu

t in

to t

he

ob

jective

s.

Re

su

lts o

f ri

sk a

sse

ssm

en

t

pro

vid

e in

pu

t in

to t

he

AM

P.

Re

su

lts o

f ri

sk a

sse

ssm

en

t

pro

vid

e in

pu

t in

to t

he

ide

ntifica

tio

n o

f a

de

qu

ate

reso

urc

es.

Re

su

lts o

f ri

sk a

sse

ssm

en

t

pro

vid

e in

pu

t in

to t

he

ide

ntifica

tio

n o

f tr

ain

ing

an

d c

om

pe

ten

cy n

ee

ds.

Re

su

lts o

f ri

sk a

sse

ssm

en

t

pro

vid

e in

pu

t in

to t

he

de

term

ina

tio

n o

f co

ntr

ols

for

asse

t life

cycle

activitie

s.

Re

su

lts o

f ri

sk a

sse

ssm

en

t

pro

vid

e in

pu

t in

to t

he

org

an

isa

tio

n's

ove

rall r

isk

ma

na

ge

me

nt

fra

me

wo

rk.

PAS-55 Aligned



Section

97 e

Identificationandassess-mentofriskconsider

stakeholderriskssuchasfailuretomeetregulatory

performance.

4 CompliantTheriskassessmentconsidersenvironmental,unethicalbehaviourandfinancialfactorswith

stakeholderrisks.5.7

98 f

Identificationandassess-mentofriskconsiderrisksassociatedwithdifferentlifecyclephasesoftheassets.

3 Developing

Thisiscoveredbythe2011AMPbutthiscouldbestrengthenedwithanexplicitstatementinthedraftAMSSection5.7.RegularinspectionsarestatedasastrategyindraftAMSSection5.7.

Thisisstilloutstanding

5.7



Inordertomanageriskseffectively,theconsiderationofriskshouldbeembeddedintoallactivitiesandproceduresthroughouttheassetmanagementsystemandpreferablyassetrelatedrisksshouldbeaddressedaspartoftheorganisation’scorporateriskmanagementframework

Recommended Actions

ThatWestpowerreviewitsoverarchingriskmanagementprocessbasedupontherequirementsofPAS-551andAS/NZSISO31000:2008,RiskManagement–PrinciplesandGuidelines.

8.12.18LegalandOtherRequirements

“Theorganisationshallestablish,implementandmaintainprocessesandproceduresforidentifyingandaccessingthelegal,regulatory,statutoryandotherassetmanagementrequirements.”



Section

4.4.7.8 Use and Maintenance of Asset Risk Information

99 aResultsofriskassessmentprovideinputintothe

strategy.4 Compliant

StrategiesaredevelopedtomitigaterisksasstatedindraftAMSSection5.7.TheRiskMan-agementPlanSection1.3statesummariestheintegrationofriskprocessesincludingthatriskassessmentprovidesinputintothestrategy.

5.7

100 bResultsofriskassessment

provideinputintotheobjec-tives.

4 Compliant

TheRiskManagementPlanSection1.3statesummariestheintegrationofriskprocessesincludingthatriskassessmentprovidesinput

intotheobjectives.

5.7

101 c ResultsofriskassessmentprovideinputintotheAMP. 4 Compliant

TheRiskManagementPlanSection1.3statestheintegrationofriskprocessesincludingthatriskassessmentprovidesinputintotheAMP.

5.7

102 d

Resultsofriskassessmentprovideinputintothe

identificationofadequateresources.

4 Compliant ThisisdetailedintheRiskManagementPlan,anassociateddocument. 5.7

103 e


identificationoftrainingandcompetencyneeds.

4 CompliantRegularstafftrainingforsystemoperationandpermitissuingisdetailedindraftAMSSection

5.7.5.7

104 f

Resultsofriskassessmentprovideinputintothede-terminationofcontrolsforassetlifecycleactivities.

4 CompliantStrategiesaredevelopedtomitigaterisksas

statedindraftAMSSection5.7,suchasregularinspection,anddistributionautomation.

5.7

105 g


organisation’soverallriskmanagementframework.

4 Compliant

TheRiskManagementPlanstatesthatitispartofoverallbusinessplanningstrategyandpro-videsinputintotheorganisation’soverallrisk

managementframework.

5.7


Review against PAS-55 requirements


Thiselement requires that theorganisationhaveaprocess formonitoring relevant legislation,codes,guidesandstandards.Anychangesshouldbeassessedforrelevanceandrequiredactionsimplemented.Westpowerhasdevelopedaregisteroflegislation,codes,guidelinesandstandardsthatareofsufficientimportancetotheassetmanagementsystem.A legislationsignoffwasviewed,which indicatesthatWestpower isawareof itsobligationsandthatithasassessedcompliance.Noevidencewaspresentedindicatinganongoingprocessformonitoringandreactingtochanges.

0

1

2

3

4

5

6

Org

an

isa

tio

n a

wa

re h

ow

its a

ctivitie

s a

re a

ffe

cte

d

by le

ga

l a

nd

oth

er

req

uire

me

nts

.

Org

an

isa

tio

n o

pe

rate

s a

syste

m to

id

en

tify

leg

isla

tio

n a

nd

mo

nito

r

fort

hco

min

g c

ha

ng

es.

Org

an

isa

tio

n h

as

ap

pro

pria

te m

ea

ns to

acce

ss in

form

atio

n.

Org

an

isa

tio

n h

as

gu

ida

nce

fro

m o

the

r

org

an

isa

tio

ns.

PAS-55 Aligned



tion

4.4.8 Legal and Other Requirements

106 aOrganisationawarehowitsactivitiesareaffectedbyle-galandotherrequirements.

4 Compliant Westpower’slegalrequirementsaresum-marisedindraftAMSSection5.8. 5.8

107 b

Organisationoperatesasystemtoidentifylegislationandmonitorforthcoming

changes.

4 CompliantWestpowerbelongstotwoorganisationsENAandEEAthatmonitorlegislationasstatedin

draftAMSSection5.8.5.8

108 cOrganisationhasappro-priatemeanstoaccess

information.4 Compliant

WestpoweraccessesrequiredinformationthroughserviceproviderENAasstatedindraft

AMSSection5.8.5.8

109 d Organisationhasguidancefromotherorganisations. 4 Compliant

GuidancefromotherorganisationsismainlythroughserviceproviderENAasstatedindraft

AMSSection5.8.5.8


Recommended Actions

ThatWestpower develop an on-going process formonitoring and reacting to changes that are of sufficientimportancetotheassetmanagementsystemtowarrantmonitoringandassignresponsibilitytoanindividualtoperiodicallycheckforamendments,revisionsetc.Eachrevision/amendmentwouldbecheckedforrelevanceandrequiredactionidentifiedanddocumented.

8.12.19ManagementofChange

“Whereexistingarrangementsarerevisedornewarrangementsareintroducedthatcouldhaveanimpactonassetmanagement activities, theorganisation shall assess the associated risks before the arrangements areimplemented.”

ReviewagainstPAS-55requirements


Theorganisationshouldensurethatriskassessmentsareperformedforanysignificantchangestoelementsofassetmanagementsystems.Thisdoesnotnecessitateadditionalriskmanagementprocessesbutensuresthereareexistingarrangementsinplacetoprovideassurancethatriskassessmentiscarriedout.WestpowercarriesoutthisfunctionthroughitsMaterialEvaluationGroup(MEG)andcarriesthisovertotheintroductionofnewcontractors.

0

1

2

3

4

5

6

Co

nsid

er

revis

ed

org

an

isa

tio

na

l str

uctu

re,

role

s a

nd

re

sp

on

sib

ilitie

s.

Co

nsid

er

revis

ed

asse

t

ma

na

ge

me

nt p

olicy,

str

ate

gy, o

bje

ctive

s a

nd

pla

ns.

Co

nsid

er

revis

ed

pro

ce

sse

s a

nd

pro

ce

du

res.

Co

nsid

er

the

in

tro

du

ctio

n

of n

ew

asse

ts, syste

ms

an

d te

ch

no

log

y.

Co

nsid

er

the

in

tro

du

ctio

n

of n

ew

co

ntr

acto

rs.

PAS-55 Aligned


Recommended Actions

ThatWestpowerensureallnewprocessesandproceduresareevaluatedviatheMEGcommittee.

8.12.20LifeCycleActivities

“Theorganisationshallestablish,implementandmaintainprocessesandproceduresfortheimplementationofitsassetmanagementplanandcontrolofactivitiesacrossthewholelifecycle.”


0

1

2

3

4

5

6

AM

P in

clu

de

s t

he

cre

atio

n,

acq

uis

itio

n a

nd

en

ha

nce

me

nt

of

asse

ts.

AM

P in

clu

de

s t

he

utilisa

tio

n o

f a

sse

ts.

AM

P in

clu

de

s t

he

ma

inte

na

nce

of

asse

ts.

AM

P in

clu

de

s t

he

de

co

mm

issio

nin

g a

nd

dis

po

sa

l o

f a

sse

ts.

PAS-55 Aligned



Section

4.4.9 Management of Change

110 aConsiderrevisedorganisa-tionalstructure,rolesand

responsibilities.4 Compliant

TheMaterialEvaluationGroup(MEG)isasubgroupoftheAssetManagementGroupandisresponsibleformonitoringandcontrolling

change.

14

111 bConsiderrevisedassetman-agementpolicy,strategy,objectivesandplans.

4 Compliant TheMEGcoversallaspectsofchangewithintheAMS. 14

112 c Considerrevisedprocessesandprocedures. 4 Compliant

ThisiscoveredindraftAMSSection14andinthesupportingchangemanagementdocu-

ment.MaterialEvaluationGroup(MEG)meetsmonthlyandconsidersnewprocesses.

14

113 dConsidertheintroductionofnewassets,systemsand

technology.4 Compliant

TheMEGcontrolsthemanagementofnewproductstobeusedontheWestpowernet-work.ChangestoassetsaretrackedinGISas

statedindraftAMSSection14.

14

114 e Considertheintroductionofnewcontractors. 4 Compliant TheMEGcontrolstheintroductionofnewcon-

tractorsasstatedindraftAMSSection14. 14



The organisation should ensure the planned arrangements, functional policies, standards, processes andprocedures, asset management enablers and resources are utilised for the efficient and cost effectiveimplementation of assetmanagement across the full life cycle of the assets. Westpower carries out theseactivitiesincompliancewiththerequirementsofPAS-55.

Recommended Actions

ThatWestpowerperiodicallyreviewstheseactivitiestocontinuallyimprovelifecycleactivities.

8.12.21Tools,FacilitiesandEquipment

“Theorganisationshallensuretools,facilitiesandequipmentaremaintainedand,whereappropriate,calibrated.”


0

1

2

3

4

5

6

To

ols

, fa

cilitie

s a

nd

eq

uip

me

nt

ca

lib

rate

d a

nd

ma

inta

ine

d f

or

the

imp

lem

en

tatio

n o

f th

e

AM

P.

To

ols

, fa

cilitie

s a

nd

eq

uip

me

nt

ca

lib

rate

d a

nd

ma

inta

ine

d t

o a

ch

ieve

th

e

req

uir

ed

fu

nctio

n a

nd

pe

rfo

rma

nce

fro

m t

he

asse

t a

nd

asse

t syste

ms.

To

ols

, fa

cilitie

s a

nd

eq

uip

me

nt

ca

lib

rate

d a

nd

ma

inta

ine

d t

o m

on

ito

r a

nd

me

asu

re p

erf

orm

an

ce

an

d

co

nd

itio

n.

PAS-55 Aligned

Table 8.12.20 4.5 - Implementation of Asset Management Plans


tion

4.5.1 Life cycle Activities

115 aAMPincludesthecreation,acquisitionandenhance-

mentofassets.4 Compliant

Thisisprovidedinthe2011AMPinSections5and6.ThestatementaboutnotdeliveringtheplannedcapitalprogrammeinRequirement4.1.2eshouldbelocatedinSection15.

15

116 b AMPincludestheutilisationofassets. 4 Compliant Thisisprovidedinthe2011AMPinSection5. 15

117 c AMPincludesthemainte-nanceofassets. 4 Compliant Thisisprovidedinthe2011AMPinSection6. 15

118 dAMPincludesthedecom-missioninganddisposalof

assets.4 Compliant Thisisprovidedinthe2011AMPinSection6. 15



Theorganisationshouldestablishandmaintainprocessesandprocedures tocontrol thesemaintenanceandcalibrationactivitieswheresuchtools,facilitiesandequipmentarenecessaryfortheimplementationofassetmanagement.WestpowercarriesoutsuchactivitiesandformallydocumentthemaintenanceandcalibrationresultsasrequiredbyPAS-55.

Recommended Actions

ThatWestpowerformallyreviewthedocumentedmaintenanceandcalibrationactivities.

8.12.22PerformanceandConditionMonitoring

“Theorganisationshallestablish,implementandmaintainprocessesandprocedurestomonitorandmeasuretheperformanceoftheassetmanagementsystemand/orconditionoftheassets.”


0

1

2

3

4

5

6

Pro

ce

sse

s a

nd

pro

ce

du

res

imp

lem

en

ted

fo

r

co

nsid

era

tio

n o

f re

active

mo

nito

rin

g o

f th

e A

MS

.

Co

nsid

era

tio

n o

f p

roa

ctive

mo

nito

rin

g o

f th

e A

MS

.

Co

nsid

era

tio

n o

f le

ad

ing

pe

rfo

rma

nce

in

dic

ato

rs o

f

the

AM

S.

Co

nsid

era

tio

n o

f la

gg

ing

pe

rfo

rma

nce

in

dic

ato

rs o

f

the

AM

S.

Co

nsid

era

tio

n f

or

qu

alita

tive

an

d q

ua

ntita

tive

me

asu

res o

f th

e A

MS

.

Co

nsid

era

tio

n o

f o

ve

rall

eff

ective

ne

ss a

nd

eff

icie

ncy o

f th

e A

MS

.

Co

nsid

era

tio

n f

or

reco

rdin

g m

on

ito

rin

g a

nd

me

asu

rem

en

t d

ata

an

d

resu

lts.

PAS-55 Aligned

Table 8.12.21 4.5 - Implementation of Asset Management Plans


Section

4.5.2 Tools, Facilities and Equipment

119 a

Tools,facilitiesandequip-mentcalibratedandmain-tainedfortheimplementa-

tionoftheAMP.

4 CompliantThisisdetailedinAMSSection15software

programmes,MaximoandSharepoint,fortheimplementationoftheAMP.

15

120 b

Tools,facilitiesandequip-mentcalibratedandmaintainedtoachieve

therequiredfunctionandperformancefromtheasset

andassetsystems.

4 Compliant ThisisdetailedinAMSSection15withrealtimemonitoring. 15

121 c

Tools,facilitiesandequip-mentcalibratedand

maintainedtomonitorandmeasureperformanceand

condition.

4 CompliantThisisdetailedinAMSSection15withMaximo.Equipmentisidentifiedandtrackedthroughthetestroomandrecordedinanassetregister.

15



Theintentofthisgroupofrequirementsistoensurethattheassetmanagementsystemhaseffectivefeedbackloops formeasurement control and continual improvement.Westpower has a number of key performanceindicators inplaceforessentialssuchasSAIDIandSAIFI,but it isnotclearthatall informationnecessaryforoperationalcontrolandcontinualimprovementoftheoverallassetmanagementsystemisinplace.

Recommended Actions

ThatWestpowerimplementperformancemeasurestoprovideimprovedmeasurementandcontroloftheassetmanagementprocesses.IndevelopingKPIensurethattheresultsofriskassessmentsaretakenintoconsiderationtoensurethatriskissueshaveappropriatelevelsofmeasurementandcontrol.

8.12.23InvestigationofAssetRelatedFailures,IncidentsandNon-Conformities

“The organisation shall establish, implement and maintain processes and procedures for the handling ofinvestigationsoffailures,incidentsandnonconformitiesassociatedwithassetsandassetmanagementsystem.”

Table 8.12.22 4.6 - Performance Assessment and Improvement


Section

4.6.1 Performance and Condition Monitoring

122 a

Processesandproceduresimplementedforconsider-ationofreactivemonitoring

oftheAMS.

4 Compliant

ReactivemonitoringofassetperformanceisdetailedindraftAMSSection16.1.ThisalsoincludeshowtheAMSismeasuredusingthe

gapanalysis.

16.1

123 b ConsiderationofproactivemonitoringoftheAMS. 4 Compliant

ProactivemonitoringofassetperformanceisdetailedindraftAMSSection16.1.TheAMS

effectivenessisreviewedannually.16.1

124 cConsiderationofleadingperformanceindicatorsof

theAMS.3 Developing

TheleadingperformanceindicatorforassetperformanceisassetinspectionasdetailedindraftAMSSection16.1.Staffmoraleissug-

gestedastheleadingKPIfortheAMS.Perhapsharderordirectmeasuresaremoreappropri-atesuchasspecificcustomerfeedbacktrends,trendsinnumberofreportsofnoncompliance,

andAMSauditresults.

16.1

125 dConsiderationoflaggingperformanceindicatorsof

theAMS.4 Compliant

ThelaggingperformanceindicatorforassetperformanceisSAIDIandSAIFIasdetailedindraftAMSSection16.1.Thelaggingperfor-

manceindicatorforAMSisannualauditsofPAS55gapanalysis.

16

126 eConsiderationforqualitativeandquantitativemeasures

oftheAMS.4 Compliant

TheAMSismeasuredqualitativelyandquan-titatively.TheAMSismeasuredqualitativelythroughtheCommerceCommissionreviews

andcomparisons.TheAMSismeasuredquan-titativelythroughSAIDIandreportedtothe

Boardmonthly.

16

127 fConsiderationofoverallef-fectivenessandefficiencyof

theAMS.4 Compliant

TheeffectivenessandefficiencyoftheAMSismeasuredthroughthePAS55gapanalysisandannualaudit,andtheCommerceCommission

reviewsandcomparisons.

16

128 gConsiderationforrecordingmonitoringandmeasure-mentdataandresults.

4 Compliant

TherecordingofdataisdetailedindraftAMSSection16.1includingdatacollectionpro-

grammeandoutageinformationtoallowforanalysis.

16




Westpower has a formalised processes for investigating, learning from and correcting the root causes ofequipment failures and process non-conformances. Such a process provides guidance onwhat level issuesneedtobeescalatedbasedonseverity,providefortimeframesforcompletionofinvestigationsandprocessfortrackingtheprogressofcorrectiveactions.

0

1

2

3

4

5

6

Pro

ce

sse

s a

nd

pro

ce

du

res

to d

efin

e r

esp

on

sib

ilitie

s

an

d a

uth

ori

ty f

or

takin

g

actio

n t

o m

itig

ate

co

nse

qu

en

ce

s a

risin

g

fro

m a

fa

ilu

re.

Inve

stig

atin

g f

ailu

res,

incid

en

ts a

nd

no

nco

nfo

rmitie

s t

o

de

term

ine

th

eir

ro

ot

ca

use

.

Eva

lua

tin

g t

he

ne

ed

fo

r

pre

ve

nta

tive

actio

n t

o

avo

id f

ailu

res o

ccu

rrin

g.

Co

mm

un

ica

tin

g t

o r

ele

va

nt

sta

ke

ho

lde

rs,

the

re

su

lts

of

inve

stig

atio

ns.

PAS-55 Aligned



Section

4.6.2 Investigation of Asset-related Failures, Incidents and Nonconformities

129 a

Processesandprocedurestodefineresponsibilitiesandauthorityfortakingactiontomitigateconsequencesarisingfromafailure.

3 Developing

TheAMGisresponsiblefordebriefingsessionsforinvestigatingassetrelatedfailures,incidencesandnonconformitiesassummarisedindraft

AMSSection16.2.Thereisnoformaldocumen-tationforthisprocessbutminutesaretakenofthesemeetings.Formaldocumentationcoveringallmatters(assetfailuresandAMSnonconfor-

mities)isrequiredtorateascompliant.

16.2

130 b

Investigatingfailures,incidentsandnonconformi-tiestodeterminetheirroot

cause.

3 Developing

Rootcausesaredeterminedthroughthedebrief-ingsessionsasabove.ThereisanewIncidentInvestigationReportsetuptodocumentthe

findings.

16.2


Recommended Action

ThatWestpower summarises and reviews its process for investigating asset failures and assetmanagementsystemnon-conformancesincludingaprocessfortrackingtheprogressofcorrectiveactions.

8.12.24EvaluationofCompliance

“The organisation shall establish, implement and maintain processes and procedures for evaluation of itscompliancewithapplicablelegalandotherregulatoryrequirements.”



ItisunderstandthatWestpoweroperatesunderheavyregulatoryrequirementsandhasprocessesandproceduresinplacetoevaluateitscompliance.

0

1

2

3

4

5

6

Org

an

isa

tio

n e

sta

blish

ed

,

imp

lem

en

ted

an

d

ma

inta

ine

d p

roce

sse

s a

nd

pro

ce

du

res f

or

eva

lua

tio

n

of

its c

om

plia

nce

with

le

ga

l

an

d o

the

r re

gu

lato

ry

req

uir

em

en

ts.

PAS-55 Aligned



Section

131 cEvaluatingtheneedfor

preventativeactiontoavoidfailuresoccurring.

3 DevelopingMajorassetfailuresareinvestigatedwithcorrec-tiveactionsaresummarisedindraftAMSSection

16.2.16.2

132 dCommunicatingtorelevantstakeholders,theresultsof

investigations.3 Developing

TheresultsofinvestigationsarecommunicatedtostakeholdersassummarisedindraftAMS

Section16.2.16.2


Recommended Actions

ThatWestpowersummarisesitscompliancereportsandholdsthedocumentationinSharepointsothereviewprocesscanmonitorcompliance.

8.12.25Audit

“Auditprogramsshallbeplanned,established,implementedandmaintainedbytheorganisation,basedontheresultsofriskassessmentsandpreviousaudits.”



Westpowerdoesnotappeartohaveaformalprogrammeofauditsoftheassetmanagementsystemanditsprocesses.Itisrecommendedthatanauditprogramofkeyprocessesandactivitiesbeimplementedfollowingtheimplementationofformalassetmanagementsystem.

0

1

2

3

4

5

6

Au

dits c

on

du

cte

d to

de

term

ine

if th

e A

MS

co

nfo

rms to

pla

nn

ed

arr

an

ge

me

nts

fo

r a

sse

t

ma

na

ge

me

nt.

Au

dits c

on

du

cte

d to

de

term

ine

if th

e A

MS

ha

s

be

en

im

ple

me

nte

d a

nd

ma

inta

ine

d.

Au

dits c

on

du

cte

d to

de

term

ine

if th

e A

MS

is

effe

ctive

in

me

etin

g th

e

org

an

isa

tio

n's

po

licy,

str

ate

gy a

nd

ob

jective

s.

Pro

vid

e in

form

atio

n to

ma

na

ge

me

nt.

PAS-55 Aligned



tion

4.6.3 Evaluation of Compliance

133 a

Organisationestablished,implementedandmain-tainedprocessesandpro-ceduresforevaluationofitscompliancewithlegalandotherregulatoryrequire-

ments.

4 CompliantLegalcomplianceisreportedtotheBoardas

detailedindraftAMSSection17alongwithKPIonzeroregulatorybreaches.

16


Recommended Action

ThatWestpowerimplementanauditprogramtoidentifynon-conformitiesandimprovementopportunitiesforkeyassetmanagementsystemprocesses.

8.12.26CorrectiveandPreventativeAction

“Theorganisationshallestablish,implementandmaintainprocessesandproceduresforinvestigatingcorrectiveactionforeliminatingthecausesofpoorperformanceandnonconformities.”


0

1

2

3

4

5

6

Inve

stig

atin

g c

orr

ective

actio

ns f

or

elim

ina

tin

g

po

or

pe

rfo

rma

nce

an

d

no

nco

nfo

rmitie

s.

Inve

stig

atin

g p

reve

nta

tive

actio

n f

or

elim

ina

tin

g t

he

po

ten

tia

l ca

use

s o

f

no

nco

nfo

rmitie

s o

r p

oo

r

pe

rfo

rma

nce

.

PAS-55 Aligned



Section

4.6.4 Audit

134 a

Auditsconductedtodeter-mineiftheAMSconformstoplannedarrangementsfor

assetmanagement.

3 Developing

TherehavebeenongoingauditsforAMplan-ningincludingPAS55auditsandreviewsas

summarisedindraftAMSSection18.TheAMSisstillnotcompliantsounabletorateascompli-

antuntilfullyimplemented.

18

135 b

Auditsconductedtodeter-mineiftheAMShasbeenimplementedandmain-

tained.

3 Developing

TherehavebeenongoingauditsincludinggapanalysisforWestpowertoseekfullPAS55com-plianceassummarisedindraftAMSSection18.Unabletogetfullmarksuntilfullyimplemented.

18

136 c

Auditsconductedtodeter-mineiftheAMSiseffectiveinmeetingtheorganisa-tion’spolicy,strategyand

objectives.

3 Developing

ThiscannotbeevaluateduntiltheAMSisfullyimplemented.ItisexpectedthatfutureauditswillevaluatetheAMSeffectivenesssounableto

rateascompliantuntilfullyimplemented.

18

137 d Provideinformationtoman-agement. 3 Developing

Theauditsfindingsneedtobeformallyprovidedtomanagement(andtheBoard).ThisshouldbeexplicitlystatedindraftAMSSection18.

18



Where corrective or preventative action identifies new or changed risks, or the need for new or changedprocedures,theproposedactionsshallberiskassessedpriortoimplementation.

Recommended Action

ThatWestpowerformallyintroduceprocessesandproceduresthatassesstheriskofcorrectiveandpreventativeactions.

8.12.27ContinualImprovement

“Theorganisationshallestablish,implementandmaintainprocessesandproceduresforidentifyingopportunitiesandassessing,prioritisingandimplementingactionstoachievecontinualimprovement.”




tion

4.6.5.1 Corrective and Preventative Action

138 a

Investigatingcorrectiveactionsforeliminatingpoorperformanceandnoncon-

formities.

3 Developing

TheprocessforinvestigatingcorrectiveactionsissummarisedindraftAMSSection16.2for

assetfailuresandlargerfaults.Thereneedstobemoreactionstoaddresstherootcausesofidentifiednonconformancestorateascompli-ant.Thismayincludechangestoprocessorrisk

profiles.

16.2

139 b

Investigatingpreventativeactionforeliminatingthepotentialcausesofnoncon-formitiesorpoorperfor-

mance.

3 Developing

Therearedebriefingsessionsforlargerfaultswithminutestaken.TheIncidentInvestigationReportincludescorrectiveaction.Thereneedstobemoreactionstoaddresstherootcausesofidentifiednonconformancesbeforetheinci-

dentsoccurtorateascompliant.

16.2

0

1

2

3

4

5

6

Op

tim

al co

mb

ina

tio

n o

f

co

sts

, a

sse

t re

late

d r

isks

an

d t

he

pe

rfo

rma

nce

an

d

co

nd

itio

n o

f a

sse

ts a

nd

asse

t syste

ms a

cro

ss t

he

life

cycle

of

the

asse

ts.

Pe

rfo

rma

nce

of

the

AM

S.

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ly s

ee

k a

nd

acq

uir

e

kn

ow

led

ge

ab

ou

t n

ew

AM

rela

ted

te

ch

no

log

y a

nd

pra

ctice

s.

PAS-55 Aligned



Theorganisationshallactivelyseekandacquireknowledgeaboutnewassetmanagement-relatedtechnologyand practices, including new tools and techniques, and these shall be evaluated to establish their potentialbenefittotheorganisation.

Recommended Action

ThatWestpowercontinueimprovementasanongoingprocessanddocumenttheactivitiesundertaken.

8.12.28Records

“The organisation shall establish and maintain records as necessary to demonstrate conformance to therequirementsofitsAMSandofPAS-55.”


0

1

2

3

4

5

6

Ke

ep

re

co

rds o

f e

sse

ntia

l in

form

atio

n g

en

era

ted

wh

ilst

resp

on

din

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o a

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g in

cid

en

ts a

nd

em

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s.

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f th

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pro

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.

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rds f

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an

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f to

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asu

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of

the

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t syste

ms a

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S.

Ke

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va

lua

tio

ns o

f co

mp

lia

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with

le

ga

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an

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ire

me

nts

.

Ke

ep

re

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n t

he

re

su

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f a

ud

its.

Ke

ep

re

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rds o

n t

he

de

tails o

f co

rre

ctive

an

d

pre

ve

nta

tive

actio

ns.

Ke

ep

re

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rds o

f m

an

ag

em

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ws.

Ke

ep

re

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rds o

f a

sse

t m

an

ag

em

en

t re

late

d

co

mp

lain

ts.

Ke

ep

re

co

rds o

f th

e r

esu

lts o

f id

en

tifica

tio

n o

f ri

sks.

Ke

ep

re

co

rds o

f p

ert

ine

nt

co

ntr

acto

r a

nd

su

pp

lie

r

info

rma

tio

n.

Ke

ep

re

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rds o

f e

me

rge

ncy p

rep

are

dn

ess a

nd

resp

on

se

, in

clu

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g t

he

re

su

lts o

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stin

g c

on

tin

ge

ncy

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ns.

PAS-55 Aligned



tion

4.6.5.2 Continual Improvement

140 a

Optimalcombinationofcosts,assetrelatedrisksandtheperformanceand

conditionofassetsandassetsystemsacrossthelifecycle

oftheassets.

3 Developing

ThecontinuousimprovementprocessisthroughtheAMPprocessandtheAMGasstatedindraftAMSSection19.Itisiterativebutitisrecog-

nisedthatthereisnoformaldocumentationforthereviewprocesssounabletoachievecompli-

ancestatus.

19

141 b PerformanceoftheAMS. 4 CompliantWestpowermonitorstheperformanceoftheAMSthroughtheirPAS55gapanalysis,as

statedindraftAMSSection19.19

142 c

ActivelyseekandacquireknowledgeaboutnewAMrelatedtechnologyand

practices.

4 CompliantWestpowerareactiveinthisareaincludingEEAconferences,subscribingtotechnicaljournalsas

detailedindraftAMSSection19.19



WestpowerhasintroducedSharepointasameansofcompliancewithrecordkeeping.ThisprocessneedstobefullydevelopedtocomplywithPAS-55.



Section

4.6.6 Records

143 a

Keeprecordsofessentialin-formationgeneratedwhilstrespondingtoandmanagingincidentsandemergencies.

4 Compliant AllincidentsarefullyinvestigatedandrecordsarekeptofactionsinTheVault. 20

144 b Keeprecordsofthetrainingprovided. 4 Compliant

ThetrainingrecordsareheldinTheVaultforcontractorandAMG.TheassociateddocumentAMGtrainingrecordswereprovidedforthis

review.

20

145 cKeeprecordsformainte-nanceandcalibrationoftoolsandequipment.

4 CompliantThetestroomholdsrecordsofthemaintenanceandcalibrationoftoolsandequipment.ThesearetobescannedandputontoSharepoint.

20

146 d

Keeprecordsformonitoringandmeasurementofperfor-manceoftheassetsystems

andAMS.

3 Developing

RecordsformonitoringandmeasurementofperformanceoftheassetsystemsandAMShavenotyetstartedasitisanewprocess.There-

cordswillbekeptinSharepointasstatedindraftAMSSection20.Thiscriterioncannotachieve

complianceyetasnotunderway.

20

147 eKeeprecordsofevaluationsofcompliancewithlegaland

otherrequirements.4 Compliant TheRegulationRegisterrecordsevaluationsof

compliancewithlegalandotherrequirements. 20

148 f Keeprecordsontheresultsofaudits. 3 Developing

AformalAMSauditisstilltobecompletedbuttheauditfindingswillberecordedinSharepoint.Thiscriterioncannotachievecomplianceyetas

notunderway.

20

149 gKeeprecordsonthedetailsofcorrectiveandpreventa-

tiveactions.4 Compliant

RecordsarekeptinMaximoofallcorrectiveandpreventativeactions.AlsorefertothenewAM

ReviewProcessreport.16.2

150 h Keeprecordsofmanage-mentreviews. 4 Compliant

CurrentandfutureplannedmanagementreviewsaredetailedindraftAMSSection21.ThereisanewAMReviewProcesstemplatewhichislinkedasanassociateddocument.

21

151 i Keeprecordsofassetman-agementrelatedcomplaints. 4 Compliant

ThereisaformalcomplaintssystemthatisrecordedinTheVault.ThereisaComplaint

Guidelinewhichshouldbeaddedasanassoci-ateddocument.

20

152 j Keeprecordsoftheresultsofidentificationofrisks. 4 Compliant

RiskidentificationisdetailedintheRiskManage-mentAnalysis,anassociateddocument.Theassociateddocumentscontractorandsupplier

recordswereprovidedforthisreview.

20

153 kKeeprecordsofpertinentcontractorandsupplier

information.4 Compliant

ContractorandsupplierrecordsareapprovedbyAMGandmaintained.Theassociateddocu-mentscontractorandsupplierrecordswere

providedforthisreview.

20

154 l

Keeprecordsofemergencypreparednessandresponse,includingtheresultsoftest-

ingcontingencyplans.

3 Developing

TheERPisWestpower’sformalemergencypreparednessandresponseplan.Itneedstobeclearwheretheemergencydebriefrecordsarekept.ContingencyplantestinghasnotbeenrecordedtodatebutweunderstandthatWest-powerhasidentifiedthisasafutureaction.

20


0

1

2

3

4

5

6

Ma

na

ge

me

nt

revie

ws in

clu

de

th

e r

esu

lts o

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tern

al

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with

le

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em

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Inclu

de

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esu

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mm

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n w

ith

em

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es.

Inclu

de

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n w

ith

exte

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Inclu

de

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t.

Inclu

de

th

e e

xte

nt

to w

hic

h o

bje

ctive

s h

ave

be

en

me

t.

Inclu

de

pe

rfo

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nce

in

ad

dre

ssin

g in

cid

en

t

inve

stig

atio

ns a

nd

co

rre

ctive

an

d p

reve

nta

tive

actio

ns.

Inclu

de

fo

llo

w-u

p a

ctio

ns f

rom

pre

vio

us r

evie

ws.

Do

th

e m

an

ag

em

en

t re

vie

ws in

clu

de

ch

an

gin

g

cir

cu

msta

nce

s,

inclu

din

g d

eve

lop

me

nts

in

le

ga

l

req

uir

em

en

ts

Ou

tpu

ts f

rom

ma

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ge

me

nt

revie

ws a

re c

on

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an

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t re

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ws

PAS-55 Aligned

Recommended Action

ThatWestpowercontinuetodevelopand implementSharepoint forthemanagementofassetandAMSandrecords.

8.12.29ManagementReview

“TheorganisationshallreviewtheAMStoensureitscontinuingsuitability,adequacyandeffectiveness.”



Reviews shall include assessing the need for changes to the asset management system, including assetmanagementpolicy,strategyandobjectives.


Recommended Action

ThatWestpowerreviewitsAMSonanannualbasis.

8.12.30ConclusionsandRecommendations

The intent of the PAS-55 specification is to define a suite of requirements which form an effective assetmanagementsystemintendedtoensuretheconsistentdeliveryoftheorganisationsassetdependentobjectives.ThefocusofPAS-55isthereforeanendtoendprocessofdiscipline,governanceandcontrol.

Table 8.12.29 4.7 - Management Review


Section

4.7 Management Review

155 a

Managementreviewsin-cludetheresultsofinternalauditsandevaluationofcompliancewithlegalre-

quirements.

4 Compliant

PAS55gapanalysisandtheOSParethecurrentinternalsystemsforAMSmanagementreviewsasdetailedindraftAMSSection21.Anew

ReviewProcesstemplatehasbeendevelopedtoformalisetheprocessfurther.TheevaluationoflegalcomplianceissummarisedindraftAMSSection17.Asamplecompliancereportisstilltobeprovidedasanassociateddocument.

17,21

156 b Includetheresultsofcom-municationwithemployees. 4 Compliant

ThereisfullparticipationofthoseinvolvedwithallincidentinvestigationsasstatedindraftAMSSection21.OtherresultsofcommunicationwithemployeesandstakeholdersonAMSareevaluatedintheAMSReviewProcessReport

21

157 c Includecommunicationwithexternalstakeholders. 4 Compliant

Managementreviewcommunicationwithexter-nalstakeholdersisevaluatedintheAMSReview

ProcessReport.21

158 d Includereportsonassetmanagement. 4 Compliant

AssetmanagementisreviewedonanannualbasisthroughAMPandOSPprocessesasstated

indraftAMSSection21.21

159 e Includetheextenttowhichobjectiveshavebeenmet. 4 Compliant Theachievementoftheobjectivesisevaluated

intheAMSReviewProcessReport. 21

160 f

Includeperformanceinad-dressingincidentinvestiga-tionsandcorrectiveandpreventativeactions.

4 Compliant

AllincidentinvestigationsincludecorrectiveandpreventativeactionsasdetailedindraftAMS

Section16.2andarerecordedintheIncidentIn-vestigationReport.TheperformanceofIncidentinvestigationsisevaluatedintheAMSReview

ProcessReport.

16.2,21

161 g Includefollow-upactionsfrompreviousreviews. 4 Compliant Thefollow-upactionsfrompreviousreviewsare

evaluatedintheAMSReviewProcessReport. 21

162 h

Dothemanagementreviewsincludechangingcircum-stances,includingdevelop-mentsinlegalrequirements

3 Developing

ChangingcircumstancesisinferredwiththeiterativenatureofthemanagementprocessasshowninthediagramindraftAMSSection21.Thiscouldbestrengthenedbyexplicitlystating

this.

21

163 i

Outputsfrommanagementreviewsareconsideredin

reviewsoftheorganisationalstrategicplan

4 CompliantManagementreviewsfeedintothereviewoftheOSPasshowninthediagramindraftAMS

Section21.21

164 j Recordsofmanagementreviews 4 Compliant Theresultsofthemanagementreviewsare

documentedintheAMSReviewProcessReport. 21


ItshouldbenotedthatPAS-55isintendedtoapplytothemanagementofphysicalassetsbyorganisationsofallsizes,rangingfromlargenationalinfrastructureprovidersinheavilypopulatedcountries(forexampletheUKNationalGrid)tosmallregionalinfrastructureproviders.Organisationsofsuchvaryingsizewillhavedifferentneedsforthelevelofcorporategovernanceandprocessdocumentation.ItisimportantthatarelativelysmallregionalinfrastructuremanagersuchasWestpowerinterpretPAS-55inamannerthatwillassureconsistentriskmanagedperformance,withoutcreatingunnecessaryadministrativeburdenandcost.

Thekeyfindingsof this revieware centredonWestpower formally identifying, reviewing,documentingandimplementingkeyassetmanagementprocessestoformanoverallassetmanagementsystem.Ifdonesensitively,WestpowerwillbeabletodesignaPAS-55compliantsystemthatminimisestheneedforadministrativeburdenwhileassuringconsistentriskmanagedoutcomes.

WestpowerhasconsciouslydecidedanddocumentedhowitwillrespondtoeachPAS-55requirementtakingintoconsiderationthesizeandscopeoftheassetmanagementoperationandtheresourcesavailable.

AsummaryofWestpower’scurrentpositionwithrespecttodocumentationofPAS-55requirementsisshowninFigure8.4.ThischarthighlightsanumberofareaswhereWestpower’sdocumentationandsystemsaddress95%ofPAS-55requirementswithsomeminoradditionalworkrequiredtotakingthisscoreto100%

InordertoprogresstowardsfullPAS-55conformance it isrecommendedthatWestpowertakethefollowingbroadapproach:

1. Identifyandsetupaprogramofwork,includingtimelinesandresponsibilities,forfullimplementationofthedocumentedprocesses.

2. Considerthedatarequirementsandinformationflowforeachoftheidentifiedprocessesto identifyanddocumentthe‘musthave’dataandinformationrequirements.Ifgapsexistimplementadataimprovementplan.

3. Implementaformalriskmanagementprocessintegratedwiththeaboveprocesses.It issuggestedthataformalisedriskmanagementprocesswouldassistin:

• Providingassurancethatthekeyassetrelatedrisksareidentifiedandunderstood.

• Transparently demonstrating the prudence of asset management decisions whether they be to applyresourcestomitigatearisk,ortoacceptariskastolerable.

4. Implementanauditandreviewprogramtomeasureprocessconformanceanddrivecontinualimprovement.


8.13 Asset and Works Management System Development

8.13.1 Background

TheimplementationofIBMMaximo®hasbeenextremelysuccessfulandpostimplementationWestpowerhasstarted to realizegenuinebenefits. Thesechangeshavebeen successfullyembedded into standardbusinessprocessandarebeingcontinuallymonitoredandupdatedasrequired.

During 2011,Westpower’s IBMMaximo® Asset andWorksManagement System (AWMS) was upgraded tothelatestavailablespecification.ThesystemintegratorinpartnershipwithWestpower’sAWMSprojectteam,providedacomprehensivesolutionwhichmetfunctional,financialandtimebasedtargets.

IntegratedwithGISandFMISsystems,Maximo®embodiescomprehensiveassetmanagementprocesseswhichsupportmanagers,contractorsandcustomers.

DaytodayassetmanagementactivitieshavebeenfullyintegratedintoMaximo®,includingmonthlyinvoicingandwork order reconciliations. Reports have been developed to assistmanger’s interpretation of data andstrategicplanningisbecomingmorefrequentasinformationandprocessesimprove.

Figure8.6-SummaryChartShowingWestpower’sCurrentCompliancewiththeRequirementsofPAS-55.

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

4.1.1 Asset Management System

4.1.2 Review against PAS 55-1







4.4.1 Structure, Authority and Responsibilities

4.4.2 Outsourcing of Asset Management Activities

4.4.3 Training, Awareness and Competence

4.4.4 Communication, Participation and Consultation

4.4.5 Asset Management System Documentation

4.4.6 Information Management4.4.7.2 Risk Management Methodology4.4.7.7 Risk Identification and Assessment

4.4.7.8 Use and Maintenance of Asset Risk Information

4.4.8 Legal and Other Requirements

4.4.9 Management of Change

4.5.1 Life cycle Activities

4.5.2 Tools, Facilities and Equipment

4.6.1 Performance and Condition Monitoring

4.6.2 Investigation of Asset-related Failures, Incidents and

Nonconformities

4.6.3 Evaluation of Compliance

4.6.4 Audit

4.6.5.1 Corrective and Preventative Action

4.6.5.2 Continual Improvement

4.6.6 Records

4.7 Management Review

Current Practice

PAS-55 Aligned

Best Practice


Figure8.7showsthemodelforthecurrentAWMS.

8.13.2 GeographicalInformationSystem(GIS)

GISistherepositoryforallNetworkspatialdata.Itcontainsandmanagesattributiondatarelatingtolocations,polesandcablespans,whichisusedtodescribethenatureandconditionofthelocation.Thisdataassistswiththedevelopmentofthepreventativemaintenanceprogramme.GISalsoprovidesnetworkconnectivity,whichisusedtoevaluatetheimpactonconsumers,orpackageworkonfeeders,duringoutages.Thisprocessminimisesconsumerdisruption,reducescostsandfacilitatessafeworkingenvironments.

8.13.3 Maximo

Maximoistherepositoryforallassetandworksmanagementdata.Italsostoresdatarelatingtolocations,whichissynchronisedeachnightfromGIS.Maximoalsomanagesthefollowingbusinessprocesses:

Budgets

Maintenance–preventative/defects

Workflows

Outagemanagement

Conditionassessment

ODV

Assetregister

Generalmaintenance

Figure8.7-ShowstheModelfortheCurrentAWMS


Inventory

Invoicing

Workordermanagementandservicerequests

8.13.4 Maintenance

PreventativeMaintenance(PM)-Considerableeffortisbeingputtowardthepreventativemaintenanceplan.PMscheduleshavebeendevelopedwithjobplansandroutesandthesearenowusedforthemajorityofscheduledmaintenanceworkprogrammes

DuediligenceneedstobegiventothestructureappliedtothePMprocesstoensurethatitisnotoverlyarduousbutatthesametimecomprehensive.Westpowerhasconductedanengineeringassessmentofnetworkassetsand in conjunction with manufacturer’s recommendations is developing a maintenance programme, whichidentifiesthefrequencyofmaintenancerequiredandlistmaintenancetasks.ThemaintenanceprogrammeismonitoredviathePMReport.

Defects–Faultandfailuresarenowbeingreportedon.Afailurereportwhichidentifiestheproblem/cause/remedyisappliedtoall faultsandassessedbyengineers to identifyrecurringproblems.AdditionallycontractorsareencouragedtosubmitservicerequeststoWestpoweridentifyinganydamageorrepairsrequiredtothenetwork.WorkflowprocessesdirectthesetotheappropriateAssetManagementdepartment.Furtherdevelopmentworkisplannedtoprovidebetterreportingofdefectssothatfuturemaintenanceplansarebetterinformed.

8.13.5 Workflows

WorkflowsareanintegralpartofMXESandprovidesignificantbenefitstobothWestpowerandENS.Anumberofworkshopshavebeenconducteddiscussingbusinessprocessesandformulatingworkflows.Workflowsprovidethegreatestchallengesandhavethepotentialtoproducethemostsignificantbenefitstobusinessprocesses.

WestpowerhasassumedownershipofWorkflowcreationandmaintenance.Havingstaffwithintheorganisationwiththeseskillssimplifiescustomisationandensuresthatchangesaretimely.

8.13.6 OutageManagement

Throughregulatorylegislation,Westpowerisobligedtomaintaintransparentoutagemanagementsystems.In-housesystemsbasedontheGISsystemhavebeendevelopedtocarryoutthisfunction.

8.13.7 ConditionAssessment

Anadd-ontotheGISsystemhasprovidedforconditionassessmentdatacapture.ArcPad,an“outofthebox”GISpackage,hasprovidedconsiderablebenefitsovercustomisedprogramming.

ThedevelopmentofArcPadtomeettherequirementsofWestpower’sconditionassessmenthasprimarilybeendoneinhouse.

8.13.8 AssetRegister

Theassetregisteristheprimaryrepositoryforinformationrelatingtoassetlifecyclemanagementandtechnicalperformance. The asset register provides theWestpower assetmanagement groupwith the ability to trackequipment,associatedcosts,historiesandfailuresofallassets.


ThecurrentassetmodelisshowninsimplifiedforminFigure8.8.

WESTPOWERNetwork Model

GXPPoint of Supply

Sub Transmission

Zone Subs

SubTran SegmentLocations

TransformerLocations

SwitchgearLocations

VegetationLocations

SwitchgearLocations

BusLocations

CommonServices

SwitchgearLocations

SwitchgearAssets

SpanAssets

OtherAssets

SwitchgearAssets

Vegetation

Pole/TowerAssets

Zone TransformerAssets

SpanComponents

Pole/TowerComponents

Zone TransformerSpares

SwitchgearAssets

BusAssets

Asset ClassRecords

SwitchgearSpares

Attribute links

Location l inks

As set L inks


8.13.9 AssetsHeldinMaximo

Attribution,meterandconditiondataisheldforthefollowingassettypes:

DuringtheimplementationofMaximodatawastransferredfromGentracktoMaximoSystems.Themajorityofthisdatahassincebeenpurifiedandwillcontinuetobeassessedandcorrectedasrequired.

GenerallyallhighvoltagelocationsandassetsarerecordedinGISandMaximo.Recentlyaprogrammehasbeenstarted to loadall400V locationandassetdata.Thisprogramme isongoingandexpected tobecompletedwithinthenextyear.

8.13.10GeneralMaintenance

ContinualimprovementisbeingmadetoallMaximo®integratedsoftwaremodules.AdedicatedMaximo/GISadministratorisfacilitatingcoordinatedsystemmanagement,whichwillguaranteeconstantimprovementandlongevity.

8.13.11StrategicManagement

AlltheelementsofMaximo®andGISsystemsmentionedabovehaveprovidedWestpowerwithaccurateandtimely information to support the decisionmaking process. Reports have been structured formanagers atvariouslevelsoftheorganisationtoassistthemineffectivelymanagingtheirrespectivedepartments.Improvedplanning,maintenanceandreportingarecontributingtoawellperformingnetworkalongwithimprovedsecurityofsupplyforconsumers.

Asset Asset Class

OperatingEquipment

PillarBoxes

CircuitBreakers CircuitBreakers(Oil/Vacuum)and

Reclosers

ControlPanels

Disconnectors

Machines Batteries,Rectifiers,Inverters,

DC/DcConverters

Poles AllMaterialTypes

Radios/SCADA

Regulators

Relays

Transformers ZoneSub,Distribution,Metering,

Voltage,Current,Earthing

LinesandCable UndergroundandOverhead

CapacitorsandInductors


Table 9.1 - Example Risk Ratings

Risk Factor Rating Recommendations

PhysicalSecurity 30

Reviewsecurityrequirementsforeachofthesub-stations.

InvestigatebenefitsofinstallinganalarmsysteminFranzJosefsub-stationmonitoredthroughSCADAandpersonnelpagers.

KeyRegisterneedstobeupdatedandunreturnedkeysretrievedwherepossible.Ifthiscannotbedonethenanassessmentshouldbemadeofcriticalsecuritypointsandlocksreplacedinthese

places.

PlantMaintenance 24

Continuetheprocessofimprovementoftheexistingplantmaintenanceandlifecycleplanningandreportingstrategy.

EnsurethattheMaximoAssetWorksManagementSystem(AWMS)enhancementsarematchedwithanyrevisionstotheplantmaintenancestrategy.

ReviewtheprocessofissuingscheduledworkorderstoensureamatchtotheAssetManagementPlan.Needtoensurethereisahighdegreeofconsistency.

9.0 RISK MANAGEMENT PLANWestpowerhas a separateRiskManagement Plan (RMP) completed as part of its overall business planningstrategy.ThisincludesBusinessImpactAnalysisandBusinessContinuityPlanning.

Inaddition,WestpowerisactivelyinvolvedinaregionalLifelinesprojectlookingatwaysofmanagingtherisksinvolvedwithmajordisastersandensuringthatplansareinplacetodealwithmostofthelikelyscenarios.

Ageneraloverviewoftheriskmanagementprocessisincludedbelowtodemonstratetherobustandprofessionalapproachtakentothisimportantaspectofplanning.

TheRMPisalivingdocumentthatisregularlyupdated.

9.1 Risk Management Planning Framework

Adetailedriskassessmentwasconductedwhich:

• Definedspecificrisks;

• Assessedthepotentialimpactofeachriskonasix-pointscalefrom100[Minor]to600[Critical];

• Assignedmanagementresponsibilitytoeachrisk;

• Identifiedcurrentcontrolmeasuresforallriskswithapotentialimpactof300[Major]oraboveandratedtheeffectivenessofthecontrols;

• Exploredthelikelihoodofoccurrence;

• Documentedtheresults.

The methodology adopted was consistent with the joint Australian and New Zealand Standard AS/NZSISO31000:2009. It is a simple andeffectivemethod,but remains subjective. The validityof the risk controlassessmentsmayrequirefurtherinvestigationandanalysisbyWestpower,particularlywheretheriskiscriticaltothebusiness.AnexampleofoneoftheoutputsisshowninTable9.1.

9.2 Risk Planning Methodology

TheriskmanagementteamfacilitatedaworkshopwithWestpower’smanagementtoworkthroughandassesstheimpactof60riskspresentedinaframeworkunder13categories.

Figure9.2chartsthemethodologyusedforWestpower.Inthisdiagram,theprocessboxes,numbered1to10,correspondwiththeprocessmethodologystagedescriptionsthatfollow.

RISKMANAGEMENTPLAN 299

Stage 1. Assess Potential Risk Consequence

Riskismeasuredintermsofconsequenceandlikelihood.Attheworkshop,Westpowermanagementassessedthepotentialimpactofeachriskontheorganisation.TheirassessmentofthepotentialriskconsequencewasbasedonthefollowingtabledevelopedinconsultationwithseniorWestpowerManagement.

Figure9.2-WestpowerRiskPlanningMethodology


Stage 2. Identify Responsibility

Oneofthetaskscompletedattheworkshopwastoidentifytheresponsiblepersonforeachoftherisksgivenaconsequencerating.Itisthepersonidentifiedthatisbestabletoratethecurrentcontroleffectiveness.

Stage 3. Identify High Consequence Risks

Akeyaimoftheriskworkshopwastoseparateoutthesignificant,high-impactrisksforfurtherattentionfromthosewithlesserimpacts.Usingacut-offriskimpactlevelof300thefollowinglistofriskswasshortlistedforfurtherattention.Eachoftheseriskswereassessedindetailininterviewsconductedwiththestaffresponsibleidentifiedattheworkshop.

Table 9.3 - Risk Consequences

Rating Level Possible Impact on Company Anualised Financial Impact

600 Critical

BoardapprovalforactionsandongoingsupportfromtheCompany’sbankersrequired.

Greaterthan$5millionHighPriorityactionsneededtorecoversituation.

Lossofstakeholdersupport.

Majorstakeholderconcern.

ViabilityofCompanythreatened.

500 Severe

DirectInterventionoftheBoard.

Between$1millionand$5million

UrgentandsustainedManagementactionrequiredtopreventcrisis.

Stakeholderuneaseandreducedsupport.

Highprofile,adversenationalmediacoverage(TV,radioandprint).

Highnumberofpeopleaffectedbyanincidentoroveryearbyinci-dents.

400 Major

ImmediateManagementactionneededtocontrolthesituation.

Between$500,000and$1million

Multipleincidentsaffectasignificantnumberofpeopleayearintotal(Non-random).

Majorstakeholderconcern.

Adversenationalmediacoverage(TV,radioandprint).

300 Significant

Managementactionneededtopreventescalation.

Between$100,000and$500,000

Multipleincidentsaffectasignificantnumberofpeopleayearintotal(Random).

Widespreadcomplaints(publicandcommunityorganisations).

Adversenationalmediacoverage(print).

200 Moderate

Actionneededtoconfirmcontrols.

Between$50,000and$100,000

Adverselocalmediacoverage(notpickedupnationally).

Localisedcomplaints(smallgroupsorcommunities).

Singleincidentaffectsasmallnumberofpeople.

100 Insignificant

CoveredundernormalManagementactions.

Lessthan$50,000Negativelocalmediacoverage.

Personalgrievanceclaim.


Stage 4. Identify Current Controls

Aspartoftheinterviewprocess,eachhighimpactriskwasdiscussedindetailandadescriptionofthecurrentcontrolmethodsdeveloped.Theseresultswerecapturedinrisktemplates.

Stage 5. Assess Control Effectiveness

Next,thecontroleffectivenessofthecurrentcontrolmethodswasassessedusingthefollowingratingscale.

Stage 6. Review Control Weakness and Loss History

Also,asapartoftheinterviewprocess,anassessmentwasmadeoftheweaknessesassociatedwiththecurrentcontrolmeasures.Atthesametime,suggestionsforimprovementswereputforwardbymanagersandabriefreviewoftherecentlosshistoryforthisriskwasnoted.

Stage 7. Assess Likelihood of Occurrence

Westpower staffwere asked to rate the likelihood of a loss against the risk exposure. The risk exposure isdeterminedbysubtractingthecontrolseffectivenessfromtheriskconsequence.

Thelikelihoodwasassessedbyusingthefollowingscale(Table9.6):

Table 9.4 - High Consequence Risks

Risk Consequence

FuturePlanning 400

CriticalAssets 336

ContractManagement 320

EmergencyManagement 300

InformationSystems 300

InformationManagement 300

UnethicalBehaviour 300

Table 9.5 - Control Effectiveness

Control Effectiveness Descriptor Definition

95% Excellent Thecontrolsinplacemitigatetherisktothemaximumextentandarebe-ingperformedinthemannerforwhichtheyweredesigned.

80% Verygood Thecontrolsandproceduresareverygood.Thereissmallroomforim-provement.

70% Good Themajorityoftheriskismanaged,howeverthereispotentialforthecontrolstofail.Animprovementisrecommended.

55% Adequate Thecontrolsandproceduresmanagetheriskatfacevalue.Thereisagreatrelianceonthemoperatingcorrectlywithoutanychecksorassurances.

45%+ Unacceptable Thecontrolsmanageonlysomeoftherisk.

30%+ Non-existent Thecontrolsarelargelypassive.

Table 9.6 - Likelihood of Occurrence

Likelihood Descripton Definition

0.95 AlmostCertain

Thereisanextremelyhighexposuretotherisk(frequency).Controlsareunlikelytopreventrealisationofpotentialimpact.

OR

Anexternalinfluencewillalmostcertainlyoccurandrendertheinternalcontrolsinoperative.


Stage 8. Calculate Exposure and Residual Risk

Theresidualriskvaluecanbecalculatedusingthefollowingformula:

Stage 9. Prioritise Risks

Byusingtheriskassessmentformulashownabove,wewereabletoprioritisethetoprisksforWestpowerbasedupontheresidualrisklevel.TherisksareshowninorderinTable9.7.

Stage 10. Action Plan Development

TheRiskManagementTeambelievesthatanyriskwitharesidualratingof5oraboveshouldbematchedbyacorrespondingActionPlan.Therearesixrisksintheabovecategory.

Thesuggestedactionplanswereformulatedfromdiscussionsheldwithkeystaffduringtheinterviewphase.ThesewillbefurtherdevelopedbyWestpowerasthisiseffectivelyalivingdocument.

ANNUALISEDPOTENTIAL RISKCONSEQUENCE

CONTROLEFFECTIVENESS

RISKEXPOSURE

RISKLIKELIHOOD

RESIDUAL RISKLEVEL- = x =

Table 9.7 - Risk Priority

Risk Residual Rank

FuturePlanning 8.0 1

Operations 7.2 2

BusinessDevelopment 7.2 3

ContractManagement 7.0 4

Financial 6.9 5

Table 9.6 - Likelihood of Occurrence

Likelihood Descripton Definition

0.75 HighlyLikely

Thereisaveryhighexposuretotherisk(frequency).Noprovisiontoidentifythehigherpotentialimpactevents.Noconfidenceincontrolstopreventrealisationofpotentialimpact.

OR

Knownexternalinfluenceshavethepotentialtorendertheinternalcontrolenvironmentinoperative.

0.5 Likely

Thereisahighexposuretotherisk(frequency).Littleprovisiontoidentifythehigherpotentialimpactevents.Lowconfidenceincontrolstopreventrealisationofpotentialimpact.

OR

Goodreasontoexpectthatexternalinfluencesmaydegradetheinternalcontrolenvironmentinop-erative.

0.2 Possible

Thereisanexposuretotherisk(frequency).Someprovisiontoidentifyhigherimpactevents.Reason-ableconfidenceincontrolstopreventrealizationofpotentialimpact.

OR

Someuneasethatexternalinfluencesmaydegradetheinternalcontrolenvironment.

0.1 Unlikely

Thereislowexposuretotherisk(frequency).Provisionsinplacetoidentifyandtreathigherimpactevents.Goodconfidenceincontrolstopreventrealisationofpotentialimpact.

OR

Littlereasontobelievethatexternalinfluencesmaydegradetheinternalcontrolenvironment.

0.05 HighlyUn-likely

Thereislittleornoexposuretotherisk(frequency).Goodprovisionsinplacetoidentifyanddealwiththehigherimpactpotentialevents.Highconfidenceincontrolstopreventrealisationofpotential

impact.

OR

Externalinfluencesarenonexistentorrarewithlongreturnperiods.


9.3 Failure Mode and Effects: Criticality Analysis

Assetfailurewillbemanagedusingthefailuremodeandeffectscriticalityanalysisprocess.Thisformspartofthe“desiredpractice”foranoptimisedrenewalstrategy.

Having identified the failure modes, risk costs and treatment options for key assets, the appropriate risktreatmentoptionwillbeincludedintheAMP.Thisprocessandthetypicalfailuremodes,effectsandtreatmentsaresummarisedinFigures9.8and9.9.

9.4 Safety

SafetyisalwaysaprimedriverinanyriskmanagementstrategyandWestpowertakesthisseriously.Toensurethatthesemattersareproperlyaddressed,aformalhealthandsafetycommitteestructurehasbeencreatedandthiscommitteecomprisesawiderangeofstafffromallareasofthebusiness.

Inaddition,Westpower’scontractor,ElectroNetServicesLtd,hasbeenauditedbytheAccidentCompensationCommission,(ACC)andreceivedatertiarylevelgradingforitssafetyprocessesandsystems,thehighestgradingavailable.

Safetyiskepttotheforethroughregularrefreshercoursesandstafftrainingprogrammesdesignedtoenhancetheawarenessofsafetyissuesthroughoutallaspectsoftheworkplace.

Inadditiontotheabove,Westpowerensuresthatanactivehazardidentificationprogrammeisinplace,includingthedevelopmentofregistersforspecifictypesofhazard.Atzonesubstations,hazardidentificationnoticeboardsareusedtoinformallpersonnelcomingontositeofidentifiedhazards.Theyareencouragedtoaddanynewhazardsthatpresentthemselvestothelist.

Figure9.8-FailureModesAnalysisProcess


Newequipmentisalwayscheckedforsafetyandspecificoperationalproceduresdevelopedwherenecessary.Allmanufacturersarerequiredtosupplymaterialsafetydatasheetsforsubstancesusedintheworkplace,andthesearekeptinareadilyavailableregister.

9.5 Environmental

OilspillsarethemostlikelyformofenvironmentaldamagetooccurasaresultofWestpower’sactivities.ThisriskhasbeenspecificallyidentifiedforfurtherattentionandhasbeenreportedatBoardlevel.

Tomitigatethisrisk,Westpowerhasinstalledbundingatallmajorsubstationswherethereareoilcontainmentvesselswithacapacityofmorethan1500litres.Allzonesubstationsarenowcompliant.

Spillresponsekitsaresuppliedtoallmajorsitesandstaffsaretrainedintheirusetomitigatetheimpactofanypotentialspill.

9.6 Key Risks Identified

KeyrisksforWestpoweraresimilarformostlinesbusinessesandaremainlyduetoclimaticandseismicfactors.

Westpowerhasidentifiedthefollowingmajorriskstoitsabilitytosupplyelectricity:

• Earthquakes,

• Storms(includinghighwinds),

• Lightning,

• Flooding,

• Rippleinjectionsystemfailure.

Figure9.9-TypicalFailureModes,EffectsandTreatments


9.6.1 Earthquake

ThelikelihoodofamajorearthquakeontheWestCoastduetoslippageontheAlpineFaultwithinthenext50yearsisconsideredtoberelativelyhigh.Thereisverylittlethatcanbedonetominimisetherisktooverheadlinesandcablesintheeventofanearthquake,butitisalsorelativelystraightforwardtostraightenpolesandrestringconductors,aslongasaccessandmaterialsareavailable.

ASeismicwithstandreportwaspreparedformostzonesubstationsinthe2003/04yeartoidentifyanyseismicstrengthening measures that can be taken to mitigate the impact of a major earthquake. Recommendedstrengtheningmeasuresidentifiedinthisreporthavebeenassessedandactionedwherenecessary.

Inaddition,Westpowercloselyco-operateswithotherELBsandusessimilar industrystandardequipmenttoensurethatareadysupplyofspareswillbeavailableifrequired.

9.6.2 StormDamage

Westpowerfacesthisriskregularly,withseveralmajorstormsexperiencedinanyoneyear.

Damageiscausedbypolesbeingblownoverand/ortreesorotherlargeobjectsbeingblownintotheoverheadlines.

Westpowermitigates this risk bymaintaining a regular pole inspection programme to check that poles areadequatelyratedandingoodcondition.Anypolesthatarefoundtobesubstandardarereplacedquickly.

AwiderangeofsparesarekeptbyWestpower’scontractor,includingpoles,conductors,fittingsandtransformerstoensurethatstormdamagecanbereadilydealtwith.Thelevelofsparesheldforvarioustypesofequipmenthasbeendevelopedthroughexperienceoveranumberofyears,andaregularreportingandreorderingprogrammeismaintainedtoensurethatminimumquantitiesaremaintained.

Inaddition,regionaldepotsaremaintainedatReefton,HokitikaandHariharisothatarapidresponsecanbeprovidedthroughoutWestpower’sarea.

9.6.3 Lightning

TheWestCoast is renownedas a significant lightning-prone regionofNewZealand, both in termsof strikedensityandintensity.

AsWestpowerhashad to livewith thisphenomenonovermanyyears, ithasdevelopeddesignpractices tominimise thedamage causedby lightning strikes. These include thefittingofmodern surgediverters on alldistributionsubstations,somethingnotcommoninmanypartsofthecountry.

Forzonesubstations,stationclass(linedischargelevel3)arrestorsarefittedontheterminalsofallmajorpowertransformers,andoverheadshieldwiresarefittedonincomingoverheadcircuits.

Asubstantialquantityofsparesareheldfortransformersaslightningisacommoncauseofdamageforthisplantandseverelightningeventscansometimeslastforseveraldays.

9.6.4 Flooding

Thisriskmainlyaffectsground-mountedassetssuchaspadmountdistributiontransformersandringmainunits.

Wherepossible,thelocationofthisequipmentischosensothatitisatleast300mmabovemaximumrecordedfloodlevels,althoughthisisnotalwaysfeasibleinareassuchastheCBDofGreymouth.

Intheeventofamajorflood,operationalplansareinplacetomakesurethatpowerisisolatedfromplantpriortofloodingreachinglevelswhereitcouldcauseanelectricalfaultandpossiblehazardstoworkersandthepublic.Ofcourse,thisisinadditiontothenormalprotectionsystemsusedtoisolateequipmentintheeventofafault.


9.6.5 RippleInjectionSystemFailure

TherippleinjectionsystemisanintegralpartofWestpower’scontrolsystemformanagingdemandonthenetworkandprovidingtariffswitchingsignalsforretailers.Afailureoftheripplesystemcouldresultinunmanageablepeaksbeingappliedtothesystem,eventuallyresultinginbrown-outsor,underextremecircumstances,black-outs.

Overrecentyears,WestpowerhasdiversifieditsbaseofrippleinjectionplantsandnowhasunitsinstalledatHokitika,Greymouth,DobsonandReefton.Thesearesynchronisedsothatifoneunitshouldfail,coverageisprovidedfromtheremainingunits.Inaddition,eachunitcanbeoperatedlocallyinanemergency.

9.7 General Mitigation Measures

AnumberofgeneralstrategiesandplansareinplacetomitigatetherisksidentifiedtoWestpower’snetworkandoperationalcapability:

1. Regularinspection,serviceandtestingiscarriedouttochecktheoperationalcapabilityofallequipment.Thisincludescheckingofvegetationincloseproximitytooverheadlinesandactivevegetationmanagement.

2. Distributionautomationhasbeenprogressivelyexpandedthroughoutthenetworkoverrecentyearsandthishasallowedadditionalplanttoberegularlymonitoredtogiveindicationsofanearlyfailure.

3. Westpowerhasnetworkdesignandconstructionstandardsaswellasamaterialsapprovalsystemtoensurethatonlyqualitymaterialsareusedandthatahighstandardofworkmanshipismaintained.Thisensuresthattheintegrityofthenetworkisprotected.

4. Regular staff training is implemented in systemoperationand the issueofpermits so thataccess to thenetworkisalwayscarriedoutinasafemanner.

5. Contingencyplansandemergencyproceduresareinplace.Includedwithintheseplansarethefollowing:

• EmergencyResponsePlan(ERP)

• Regionalemergencyloadsheddingplan

• Electricalindustryemergencycontactlist

• Zonesubstations-emergencyoperatingordertemplates. Anumberofengineeringmeasureshavebeentakentomitigateriskincluding:

• Ahealthycomplementofsparesismaintainedsothatmosteventualitiescanbecoveredwithoutresortingtoexternalsupport.

• Aseismicstrengtheningprogrammewillcontinueatzonesubstationsduringthecurrentfinancialyear.

• Afullymobile33/11kVsubstation,calledtheWestpowerMobileSubstation(WMS)hasbeenbuilttoprovidecoverageforsingle-transformerzonesubstations.Sufficientsparepowertransformersareavailabletocoverlong-termfaults.

• Sparecircuitbreakersandcontrollershavebeenpurchasedtocoverexpectedfailurerates.

9.8 West Coast Engineering Lifelines Plan: Survey 2004/2005

Executive Summary

AsanecessarypartofWestpower’songoingcommitmenttotheriskmanagementofitsWestCoastelectricitydistribution network, a selection of critical facilities within their operating area were surveyed to assesstheirvulnerabilitytodamagefromanumberofpredeterminednaturalhazards,e.g.windstormsandsevereearthquakes.


This survey is part of Westpower’s means of compliance with the requirements of the Civil Defence andEmergencyManagement Act 2002. The new act seeks to improveNew Zealand’s resilience to emergenciesthroughpromotingacomprehensiveall-hazardsapproachtomanagingrisk.

CompliancewiththeaboveActisbaseduponfour“R’s”,Reduction,Readiness,ResponseandRecovery.

Thefullreportcontainsadetailedsummaryoffindingstogetherwithcompletedvulnerabilitychartsthatquantifyriskandimportanceinasystematicway.ThesechartsarebaseduponthesystemoriginallyemployedfortheWellingtonandChristchurchengineeringlifelinestudies.Thequantificationlevelissufficienttoenablerelativerisk tobeassessed toassist aprocessofmitigatingareasof risk inaprogressivemanner fromhighest risk/vulnerability/importancetolowest.

TheWestpower network is operated from a Control Centre in the offices at their depot on Tainui Street,Greymouth.TheControlCentreisanessentialpartofWestpower’slifelinereadinessandisdesignedformaximumresilienceintheeventofamajordisaster.Whereverpossible,theControlRoomandassociatedfacilitieshavebeenbroughtup to the requirementsof the latest loadingsandmaterials standards,whichwill significantlyreducefuturevulnerabilityinthisarea.

Thefollowingmainsubstationsandswitchyardsweresurveyedaspartoftheexercise:

• Greymouthsubstation,

• Dobsonsubstation,

• Arnoldpowerstationswitchyard,

• Rapahoesubstation,

• Kumarapowerstationsswitchyard,

• Hokitikasubstation,

• Franzjosefsubstation,

• Foxsubstation.

In addition to the above, a selectionof less important substationswere surveyed to gain an assessment oftheoverall network. These included substations/switchyards atBadger Lane,Harihari,MawheraQuay,Ross,WahapoPowerStation,WaitahaandWilsonLane.

9.9 Transmission Lines

ThemajortransmissionlinesfeedingintotheWestpowerportionoftheWestCoastCivilDefenceEmergencyManagement(CDEM)areaare:

• Inangahua–BlackwaterA 110kVsingle-circuitonpoles

• Dobson–BlackwaterA 110kVsingle-circuitonpoles

• Arahura(Hokitika)–OtiraA 66kVdouble-circuitonpoles

• Arahura(Hokitika)–DobsonA 66kVsingle-circuitonpoles(betweenDobsonandGreymouth)

ThemajorTransmissionLinesthatWestpowerownthemselvesare:

• Greymouth–Kumara 66kVsingle-circuitonpoles 25km

• Kumara–Kawaka 66kVdouble-circuitonpoles 11km

• Hokitika–Harihari 66kVsingle-circuitonpoles 64km

• Two-Mile–Hokitika 66kVsingle-circuitonpoles 8km


Westpower’stransmission/distributionlinescoverseveralroutesoverwidelyvaryingterrainfromcoastalplainstorelativelyunstableandruggedhillcountry.Someredundancyisbuiltintoportionsofthesystemwherebyanoutageonanyoneparticularline,dependingupontimeofday/timeofyear,maynotaffectsupplytootherareasofthenetwork.

Mostpolessupportingtransmissionanddistributionlinesarewellfoundedtopreventcollapseunderhighwinds/iceconditions,andthereforeareonlymoderatelyvulnerabletoearthquake-inducedslopeinstability.

Figure9.10showsthemainlinesfeedingintotheWestpowernetworkfromReeftonandOtira.

KEY Substation


Subtrans Line 110kV

BWR-IGH-A

DOB-BWR-A

AHA-DOB-A



AHA-OTI-A

ATARAUATARAU


REEFTONREEFTON




OTIRAOTIRA


KUMARAKUMARA

Figure9.10-MapshowingtheTranspowerNetworksupplyingtheWestpowerDistributionNetwork.


9.10 Communications

Westpowerisabletouseanumberofindependentmeansofcommunicationtocontrolitsnetwork,namely:

• Two-wayradio,

• Telecomlandlinetelephonenetwork,

• Cellularphonenetwork(insomeareas).

Eachsystemisessentiallyindependentofeachotherandthereforethereissignificantredundancyintheeventofdisruption.

The following table (Table 9.11) is a summary of common findings throughoutWestpower’s network, withsuggestedmitigationmeasures.

9.11 Disaster Recovery

Westpower has adopted procedures and policieswhich define processes and assign responsibilities for theconductofemergencyresponseteamsanddepartmentsintheeventofadisaster.

TheseproceduresandpoliciesincludecomprehensiveEMTStandardOperatingProcedure(SOP)andDepartmentalBusinessContinuityPlans(DBCP)aswellastheEmergencyResponsePlan(ERP)andLoadSheddingPlan(LSP)asdiscussedinSection9.7,MitigationMeasures.

9.11.1 EmergencyManagementTeam

TheEMTSOPsprescribestheappropriateprocessesandassignsresponsibilitiesfortheconductoftheEMTintheeventofadisasterofsuchproportionsthatrequirescoordinatedcommandandcontrol.

TheSOPappliestoallelementsofElectroNetwhenperformingdutiesassignedbytheEMT.ThestructureoftheEMTmayaltersubjecttothenatureofthedisaster,resourcesavailableandthetacticalsituation.

TheEMTiscategorisedasfollows;

• Command&control:Includesdefinitionofrolesandresponsibilities,operatingcontrolandoverallcommandoncea‘Disaster’isdeclared.

• Planning:Whenadisasterhasbeendeclared,EMToperationswillbeconductedinthreephases.

Table 9.11 - Summary of Vulnerabilities and Suggested Mitigations

Vulnerability Suggested Mitigation

Transmissionlinespassingoverunstableterrain Adddiversificationwereeverpossible(longtermplanning)

Sometransformersandregulatorsnotrobustlyhelddown ModifyholddownsystemstocurrentEQstandards

Somebusworkvulnerabletoinsulatordamagefromsupportingpostsmovingdifferentially Provideslipjointsinbusworkatappropriatepoints

Someprefabricatedcontrolbuildingsnotrobustlyrestrained UpgradeholddownsystemstocopewithfullEQandwindloadings

Restrainbatteriesfromslidingwithsupportframesandpossiblydamagingcablesandterminals

Providecorrosionproofpackingandtiedownsmallcommuni-cationbatteries

Sometwowayradiosandaccessmanualsunrestrained Providelipstostorageshelvesandattachradiostowallsetc

Someequipmentsupportstandsungroutedwithlongholddownboltsvulnerableinbending Providesuitablenonshrinkgroutunderbaseplates

NewcontrolroomtobeasrobustaspossibleNewcontrolroomwillbeuptolateststandards.EnsureallVDU’s,computersandcommunicationequipmentwellre-

strained

Somecriticalsparesunrestrainedandvulnerable Appropriatelyrestrainallcriticalspares


• Admin and logistics: Defines the location of the EMT base of operations, including all communicationsandmaterialsavailableandalistofpriorityservices.Alsoincludedisalistofpersonnelavailableandtheircontacts.

Please refer to the document “Standard Operating ProcedureWP-01 SOP - EmergencyManagement TeamProcedures”.

9.11.2 BusinessContinuityPlans

TheBCPsaredefinedbyeachdepartmentandenablethere-establishmentofnormalprocessesandproceduresfollowingamajordisruptiveeventwhichresultsineitherthelossofbusinesspremises,resourcesorpeople.

Eachdepartmenthasdevelopedaworkableplanthatcanbeusedtopreventtheinterruptionofcriticalbusinessfunctionsintheeventofamajorinterruption.

Thedepartmentsincludestores,financial,assetmanagement,electriciansandlines.ForanoverviewoftheBCPstructure,refertoFigure9.12.

TheObjectiveoftheBCPsisasfollows:

• Todefineandprioritisethecriticalfunctionsofthedepartment;

• Toanalysetheemergencyriskstothedepartment;

• Todetailtheagreedresponsetoanemergency;

• Toidentifykeycontactsduringanemergency.

Forfurtherinformation,pleaserefertothedocument“BusinessContinuityPlanWP-BCP”

Figure9.12-BCPOrganisationStructure

APPENDIXA:MAINTENANCEACTIVITYDEFINITIONS 311

APPENDIX A: Maintenance Activity Definitions


Routine

This isexpenditureonpatrols, inspections,servicingandtestingofassetsonaroutinebasis.Typically, theseactivitiesareconductedatperiodicintervalsdefinedforeachassetortypeofasset.Thisworkdoesnotinvolveanyrepairsotherthansomeminorcomponentreplacementsinthecourseofservicing.

Special Inspection, Service and Testing

Expenditureonpatrols, inspections,servicingandtestingwhicharebasedonaspecificneed,asopposedtobeingtime-based,aswithperiodicinspectionsandservicing.

Faults

Repairsareundertakenduringfaultconditionstorestoresupply.Thisdoesnotincludetheeventualrepairofafaultedasset,whereitistakenoutofserviceinthecourseofrepairingthefault;onlytheexpenditurerequiredtorestoresupplyisincluded.

Planned Repairs and Refurbishment

Repairs toand refurbishmentofanasset,whichmay involvecomponent replacementbutnot thecompletereplacementoftheasset.This includescorrectiverepairsofdefects identifiedwithinayear,“special”repairs(e.g.basedonan identifiedtypefailureortypeweakness)andplannedrefurbishmentswhichmay involveasignificantproportionofcomponentreplacement.However,toidentifyrefurbishmentsasdistinctfromgeneralrepairswouldrequireidentificationofallspecificrefurbishmentprojectsovertheplanningperiod,andthishasnotprovedfeasibleforthisplan.

Planned Replacement

Replacementofanexistingassetwithamodernequivalentassetprovidingsimilarcapacity,orotheraspectofserviceprovided.Notethattheassetneednotbeidenticalincapacityetc.butshouldbemateriallysimilar.

Maintenance Contingency

Anexplicitplanningcontingency,whereitisnotfeasibletoidentifyallminorwork,orwhereitisexpectedthatworkwillarisebutitsclassificationcannotbeeasilypredicted.Allcontingenciesarespecificallyidentifiedandnoimplicitcontingenciesareincludedinthedetailedexpenditureprojectionsforotheractivityclassifications.

This contingency is converted into one of the above activity classifications once committed. “MaintenanceContingency”isnotarealactivityforreportingpurposes.

EnhancementandDevelopmentActivityDefinitions

Enhancement

Thisisthereplacementofanexistingassetwithamodernequivalentasset,whichmateriallyimprovesontheoriginalasset,ormodificationstoanexistingassetthathavethiseffect.Specifically,thiswillincludeimprovementstotheexistingassetconfiguration,whichareundertakenwiththepurposeof:

• Furtherimprovingtheinherentsafetyofthesystem(e.g.installingsmoke/heatdetectorsandentryalarmsinsubstations);

• Improvingthelevelofcustomerservice(e.g.increasingcapacitybyreplacingatransformerwithalargerunit,oraddinganextracircuittoittoincreasesecurity);


• Improvingeconomicefficiencyorinvestingtoimprovetheassetbyreducingoperatingormaintenancecosts(e.g.fittingvibrationdamperstospecificlinestoreducetherateofcomponentdeterioration);

• Improvingenvironmentalriskmanagement(e.g.fittingoilcontainmentfacilitiesatsubstations);

• Improvingthecorporateprofile(e.g.landscapingstationgrounds,althoughthisisalsofullyjustifiableonthebasisofreducedgroundsmaintenance).

Notethateachaspectofimprovementisrelatedtoaspecificassetmanagementperformancedriver.

Development

Thisisworkwhichinvolvestheinstallationofnewassetsinsitesorconfigurationswherenonepreviouslyexisted.Thismayalsoincludesubstantialupgradework(e.g.rebuildingasubstationatahighervoltage)inwhichtheoriginalconfigurationissignificantlyalteredorextended.

Development Contingency

An explicit planning contingencywhere it is not feasible to identify allminorwork, orwhere it is expectedthatworkwillarisebutitsclassificationcannotbeeasilypredicted.Noimplicitcontingenciesareincludedinthedetailedenhancementanddevelopmentexpenditureprojections.Forthesamereasonsasthosediscussedunder“MaintenanceContingency”,thisactivityisnotincludedinfinancialreports.

OtherActivityDefinitions

Operating

Any disconnection of a customer’s services for any reason except non-payment of electricity accounts. Thisincludesactivitiessuchashousepainting,transportationofhighloadsandlow-voltageswitching.Italsoincludesoperationofthehigh-voltagenetworkwherethisisnotdirectlyassociatedwithmaintenanceorenhancementwork.

Trees

Thisactivitycoversalltree-cuttingandtrimmingtomaintainsafeworkingclearancesfrompowerlinesandanycostsincurredduringnegotiationswithcustomersregardingtree-trimming.

AssetTypeDefinitions

High-voltage Lines

Includesallpowerdistributionandsubtransmissionlineswitharatedvoltageof11kVorhigher,togetherwithassociatedeasements.Withintheplan,lineworkisfurtherdesegregatedintomajorlinecomponents:

• Poles,

• Conductorsandaccessories,

• Insulatorsandhardware.

Low-voltage Lines

Includesalllowvoltagelineswitharatedvoltageof400Vorlower,togetherwithassociatedeasements,uptothecustomer’sservicefuse.Asforhighvoltagelines,lineworkisfurtherdesegregatedintomajorlinecomponents:

• Poles,

• Conductorsandaccessories,

• Insulatorsandhardware.

APPENDIXA:MAINTENANCEACTIVITYDEFINITIONS 313

Service Lines

Includesallservicelinesonroadreservefromthecustomer’sservicefusetothepointatwhichitcrossesthecustomer’sboundary.Theseinclude:

• Fusearms,

• Servicefuses,

• Servicelinesonroadreserve.

Zone Substations

These include substation sites and the power transformerswithin themwith a secondary voltage of 11 kVorhigher. Individual itemsofequipmentsuchasdisconnectors,circuitbreakersandbus-workarecovered inotherasset typedefinitions,whicharegeneric for thewholenetwork, i.e.nodistinction ismadebetweenadisconnectorinasubstationandoneonadistributionline.

• Powertransformers,

• Otherstationequipment,

• Regulatorsites.

Distribution Substations

Alldistributionsubstationequipmentincluding:

• Distributiontransformers,

• DDOfuses,

• Lightningarrestors,

• Earthingsystems.

Switchgear

Allhigh-voltageswitchgearandotheritemsofequipment,bothonlinesandwithinsubstations,including:

• Circuitbreakers,

• Structuresandbus-work,

• Instrumenttransformers,

• Capacitors,

• Protectionsystems,

• Metering,

• Buildings,grounds,fencesandotherservices.

SCADA, Communications and Protection

Includes SCADAMaster Station and RTUs at individual sites. Communication equipment comprises specificcommunicationssiteswithassociatedequipment,andradiocommunicationsequipmentwhichmaybeinstalledinvehicles,substationsorotherbases.Protectionassetsincludedinthisdefinitioncoverprotectionrelaysandequipment,whichisgenerallyinstalledatasubstationsite.

Buildings and Structures

Includesallbuildingassetsaswellassomeoftheolder“bunker”distributionsubstations.


Ripple Control

Ripple Injection Plants installed in zone substations. This definition also includes the load control softwareincludedintheSCADAmasterstation.

APPENDIXB&C 315

APPENDIX B: Commerce Commission Cross Reference Table

AsourAMPhasbeenstructuredtosuitourpurposesitdoesnotstrictlyfollowtheorderaslaidoutinschedule2oftheElectricityinformationdisclosurerequirements.Toassistinfindingspecificinformationthiscrossreferencetablewillpointthereadertocorrectpage(s).

Framework Ref. Com.Com Schedule 2 Ref Com.Com Handbook Ref Westpower AMP Section Ref.

B.2 Item1 4.5.1 ThroughoutSection

B2A 4.4.3,4.5.1 1

B2B 4.4.4,4.5.1* 1

B3 AMPSummary 2

B3.1 4.5.2a 2.1.1,2.1.2

B3.1A Item2a 4.5.2a 2.1.1,2.1.2

B3.1B 4.5.2a 2.1.1,2.1.2

B3.1C 4.5.2a 2.1.2

B3.2 Item2b 4.5.2b 2.1.2

B3.2A 4.5.2b(i) 2.1.7.4,2.1.7.5

B3.2B 4.5.2b(ii) 2.1.3

B3.2C 4.5.2b(iii) 2.1.1,2.1.2,2.1.2&2.1.3

B3.2D 4.5.2b 2.1.3

B3.3 Item2c 4.5.2c 2.1.1,2.1.2

B3.3A 4.5.2c 2.1.1,2.1.2

B3.3B 4.5.2c 2.1.1,2.1.2

B3.4 Item2d 4.5.2d 2.1.7

B3.4A 4.5.2d 2.1.7

B3.4B 4.5.2d(i) 2.1.7

B3.4C 4.5.2d(ii) 2.1.7

B3.4D 4.5.2d(iii) 2.1.7

B3.4E 4.5.2d(iv) 2.1.7

B3.5 Item2e 4.5.2e 2.1.6

B3.5A 4.5.2e(i) 2.1.6.1

B3.5B 4.5.2e(ii) 2.1.6.8

B3.5C 4.5.2e(iii) 2.1.6.9,2.1.6.10

B3.6

B3.6A Item2f 4.5.2f 2.1

B3.6B 4.5.2f 2.8

B3.6C 4.5.2f 2.8

B3.6D 4.5.2f 2.8

B4 3

B4.1 Item3a 4.5.3a 3

B4.1A 4.5.3a(i) 3

B4.1B 4.5.3a(ii) 3.14

B4.1C 4.5.3a(iii) 3.14

B4.1D 4.5.3a(iv) 5.4

B4.2 Item3b 4.5.3b 3.2to3.14

B4.2A 4.5.3b(i) 3.2&3.14



B4.2B 4.5.3b(i) 3.2

B4.2C 4.5.3b(ii) 3.3,3.7

B4.2D 4.5.3b(ii) 5.3.1,AppendixC

B4.2E 4.5.3b(iii) 3.4

B4.2F 4.5.3b(iv) 3.8

B4.2G 4.5.3b(v) 3.5&3.6

B4.2H 4.5.3b(vi) 3.9to3.11

B4.3 Item3c 4.5.3c 3.0(throughoutSection)

B4.3A 4.5.3c 3.0(throughoutSection)

B4.3B 3

B4.4 Item3d

B4.4A 4.5.3d 2.3&3.0(throughoutSection)

B5

B5.1 Item4a

B5.1A 4.5.4a 4.2

B5.2 Item4b

B5.2A 4.5.4b 4.3

B5.3 Item4c

B5.3A 4.5.4c 4.4

B6 4.5.5 6

B6.1 Item5a

B6.1A 4.5.5a 5.2&5.3

B6.1B 4.5.5a 5.2&5.3

B6.2 Item5b

B6.2A 4.5.5b 5.2

B6.3 Item5c

B6.3A 4.5.5c 5.4

B6.3B 4.5.5c 5.4

B6.3C 4.5.5c 5.4.2

B6.3D 4.5.5c 5.4.2

B6.3E 4.5.5c 5.4.5

B6.3F 4.5.5c 5.4.4

B6.4 Item5d

B6.4A 4.5.5d 5.7

B6.4B 4.5.5d 5.8.2

B6.5 Item5e 4.5.5e 5.4&5.5

B6.5A 4.5.5e Section5

B6.5B 4.5.5e Section5

B6.6 Item5f

B6.6A 4.5.5f 5.5

B6.6B 4.5.5g(i) 5.5

B6.6C 4.5.5g(ii) 5.5

B6.6D Item5g 4.5.5g(iii) 5.18

B6.6E 4.5.5g(note1) 5.5

B6.6F 4.5.5g(note1) 5.8-5.18

B6.6G 4.5.5g(note2) 5.8-5.18andSection7

APPENDIXB&C 317


B7

B7.1 Item6a

B7.1A 4.5.6a 6.1&6.2

B7.2 Item6b

B7.2A 4.5.6b 5.9-5.18

B7.2B 4.5.6b 5.9-5.18

B7.2C 4.5.6b 5.9-5.18

B7.2D 4.5.6b 5.9-5.18andSummarySection7

B7.3 Item6c 4.5.6c 5.9-5.18&6

B7.3A 4.5.6c 5.9-5.18,5.13.3

B7.3B Item6d 4.5.6d 5.9-5.18

B7.3C 4.5.6d(i) 5.9-5.18

B7.3D 4.5.6d(ii) 5.9-5.18

B7.3E 4.5.6d(iii) 5.9-5.18

B7.3F Item6e 4.5.6e 5.15-5.18&summaryinSection7

B8

B8A Item7 4.5.7 9

B8B Item7a 4.5.7a 9

B8C 9.5,9.6&9.11

B8D Item7b 4.5.7b 9.0(throughoutSection)

B8E 4.5.7b 9.7-9.11

B9 4.5.8 7

B9.1 Item8a

B9.1A 4.5.8a 7.3

B9.1B 4.5.8a 7.3

B9.1C 4.5.8a 7.3

B9.1D 4.5.8a 7.3

B9.2 Item8b

B9.2A 4.5.8b 4.2&4.3

B9.2B 4.5.8b 4.2&4.3

B9.3 Item8c 4.5.8c 8.13

B9.3A 4.5.8c 8.0(throughoutSection)

B9.3B 4.5.8c 8.0(throughoutSection)

B10

B10A 7.1

B10B 7.1

B10C 7.2


APPENDIX C: Network Reliability by Zone Substation and Feeder

ThetablebelowshowsthereliabilitylevelsforeachofWestpower’s19ZoneSubstations.

Substation Load (MW)

Sub-Trans Security

# HV Feeds Feeders

Restora-tion Time

(Hrs)Backup Comments

Reefton33kV 7.088 n-1 2 CB3012 <0.5 CB3072at

Sub

TherearetwotransformersfedfromInan-gahuaandAtarauthroughtwoseparate110kVcircuits.Thereisnoproblemwith

thebackup.

CB3072 <0.5 CB3012atSub

Reefton11kV 2.828 n-1 2 CB4 <0.5 CB5atSub

CB5 <0.5 CB4atSub

BWRCB1toReefton

town

Globe11kV 1.616 n 1 CB2 <1

AcceptedbyCustomer.Backupisavailablejustfor11kV.

CB3 <1

CB4 <1

MobileSubforallfeed-

ers

Globe6.6kV 4.000 n 1 CB39 NoBackup The6.6kVfeederonlysuppliestheGlobeBallMillandthereisnobackupwhichis

acceptedbyCustomer.

Ngahere 3.107 n 1 CB1 <1 DOBCB1 ThereisabackupfeedfromReeftonfora33kVfeederfault.BackupisavailablefortheBlackballfeedfromDobsonorArnold.TheCB3feedercanbefedfromBlack-water.Repairtimesareshort.Abackuptransformerisavailable.Inasubstation

fault,alternatefeedsarenotlargeenoughtosupplythemajorconnectedload,the

NgahereGoldDredge.

ALDCB3

CB3 <1 BWRCB2

MobileSubforbothfeeders

Rapahoe 2.177 n 1 CB1 <1 CB3atSubThereisnobackupfora33kVfeederfault.Backupisavailableviaabypassswitchfor33kVand11kVcircuitbreakerfaults.Dob-sonisabletosupplythedomestic11kV

load,andminimalindustrialload,e.g.minepumps.Abackuptransformerisavailable.

CB3 <1 DOBCB1

<1MobileSubforbothfeeders

Dobson33kV 13.793 n-1 2 CB1322 <0.5 CB1362at

SubThisisthemajor33kVsupplypointfor

theGreyValleyandissupplieddirectfromtheTransPowernetwork.Theradial33kVfeederscanbebypassedatthesubstationforcircuitbreakerfaultsbuttherearenoalternatefeedforthefeedersthemselves.

Repairtimesareshort.CB1382isnotprovidedwithabypass,asArnoldPower

Stationprovidesanalternatesourceonthe11kVnetwork.ThemobilesubstationcanbeusedasabackupforCB1342andT1.

CB1342 <0.5 MobileSub

CB1362 <0.5 CB1322atSub

CB1382 <0.5 33kVTietoArnold

CB3072Reefton

APPENDIXB&C 319


Sub-Trans Security

# HV Feeds Feeders

Restora-tion Time


Dobson11kV 1.875 n 1 CB1 <0.5 RAPCB3 Thissubstationisfeddirectlyfromthe

TranspowerDobson33kVbus,andsoisnotsubjecttoWestpowerSubtransmissionLineFaults.The33/11kVtransformeralsoactsasaspare,whichcanbetransportedtoNgahere,Rapahoe,Hokitika,WahapoorFranzJosefifrequired.Several11kVtiesexistforthefeedersoutofthissubstation

andrepairtimesareshort.

ALDCB3

NGHCB1

CB3 <0.5 GYMCB13


Blackwater 1.472 n 1 CB1 <1 RFNCB5

The33kVfeederbackupisavailablefromReeftonorDobson.

CB2 <1 NGHCB3


Arnold 3.357 n 1 CB3 <0.5 DOBCB1 Thebackupfora33kVfeederfaultisthelocalgeneratingstationtiedinthroughthe11kVnetwork.BackupisavailablefortheStillwaterfeedfromDobson,andforthe

MoanafeedfromKumara.PartialbackfeedtoDobsonorTuriwhateispossible.Repairtimesareshort.Abackuptransformeris

available.

CB4 <0.5 DIL4

<0.5 MobileSub

Greymouth 13.444 n-1 2 CB7 <0.5 CB12&CB9

ThisisWestpower’slargestPointofSupplythatfeedstheGreymouthCentralBusinessDistrict(CBD).Thereareseveralradial11kVfeedersthatareintermeshedatseveralpointsprovidingasignificantamountof

diversity.TheCobdenFeederhasnobackuponceitcrossestheGreyRiver,howeverthereticulationisalloverheadwithlowrepairtimes.The11kVcablenetworkintheCBDishighlyintermeshedwitha“double-ring”construction.Allsubstationshavetwo,and

manythree,11kVcablefeeds.

CB13 <0.5 CB6

DOBCB3

CB6 <0.5 CB13

CB11

KUMCB1

CB12 <0.5 CB9

CB6

CB11 <0.5 CB6

CB12

CB9 <0.5 CB7

CB12

Kumara 2.361 n 1 CB1 <1 GYMCB6 ThissupplyisfeddirectlyfromtheKumara11kVbus,whichisinturnsuppliedbyaveryreliableTranspower66kVbus.

Both11kVfeederscanbebackfedfromGreymouth,ArnoldorHokitikaSubstations.AsparetransformerisavailablefromGrey-

mouthSubstation.

CB2 <1 ALDCB4

HKKCB10



Sub-Trans Security

# HV Feeds Feeders

Restora-tion Time


Hokitika 18.452 n-1 2 CB10 <0.5 CB4

ThissubstationfeedsHokitikaandallofSouthWestlanddowntoParinga.Inaddition,itsuppliesthreefeederstothe

WestlandDairy.

CB4 <0.5 CB10

CB12

CB12 <0.5 CB4

CB5 <0.5 CB9

CB11

CB9 <0.5 CB5

CB11

CB11 <0.5 CB5

CB9

Ross 0.447 n 1 CB1 <0.5 CB3atSub CB1isadedicatedfeederfortheBirchfieldMineralsminesite.DomesticloadonCB3canbefedfromCB10.Bothfeedershavea

shortrepairtime.

CB3 <0.5 HKK10

Waitaha 0.261 n 1 CB1 <5 NoBackup The33kVsubstationfeedcanbefromHokitikaorWahapoiftheWahapoPowerStationisavailable.Thisisaverysmallandisolatedsubstationandnobackupispossibleforthe11kVfeeders.Aspare

transformerisavailable.

MobileSub

Harihari 1.044 n 1 CB1 <0.5 CB3atSub The33kVsubstationfeedcanbefromHokitikaorWahapoiftheWahapoPowerStationisavailable.Thisisasmallandiso-latedsubstationandnobackupispossibleforthe11kVfeedersapartfromabypassforthe11kVcircuitbreakers.Asparetrans-

formerisavailable.

CB3 <0.5 CB1atSub

MobileSub

Whataroa 0.772 n 1 CB1 <5 NoBackup The33kVsubstationfeedcanbefromHok-itikaorWahapoiftheWahapoPowerSta-tionisavailable.Thisisasmallandisolatedsubstationandnobackupispossibleforthe

11kV.Asparetransformerisavailable.

MobileSub

Wahapo 3.091 n 1 CB1 <5 NoBackup The11kVsubstationbuscanbefedfromHokitikaorWahapoiftheWahapoPowerStationisavailable.Thisisanisolated

substationandnobackupispossibleforthe11kV.AsparetransformerisavailablefromDobson.ThissubstationalsoconnectsWahapoPowerStationintoWestpowers

sub-transmissionnetwork.

MobileSub

FranzJosef 1.718 n 1 CB1 <1.5 CB3atSub Thissubstation,fedfromHokitikafeedstheFranzJosefarea.TherearetwosectionsofAerialBundledCableinthisfeeder,whichhavesignificantrepairtimes.Theaerialroutesandterraincanbeverydif-ficult.Thereisnofeasiblesubtransmissionbackup.Themobilesubstationcanbackup

both11kVfeeders.

CB3 <1.5 CB1atSub

MobileSub

FoxGlacier 0.750 n 1 CB1 <5 NoBackup Thissubstationwasconstructedin2003tosupplytheFoxGlacierarea,southto

Paringa.MobileSub

APPENDIXB&C 321


Sub-Trans Security

# HV Feeds Feeders

Restora-tion Time


LogburnRd33kV 0.761 n 1 CB3602 NoBackup

Thereisnobackupavailable.

LogburnRd11kV 0.343 n 1 CB1 <1 NGHCB1

BackupforCB1isavailablefromNgahereCB1viaDD22.CB2andCB3canalsobe

partiallybackedupfromNGHCB1.CB2 NoBackup

CB3 NoBackup

Pike11kV 0.761 n 1 CB1 NoBackup

AcceptedbyCustomer.Inemergency,themobilesubcouldbeinstalledtosupply

thesefeeders.

CB2 NoBackup

CB3 NoBackup

CB4 NoBackup

CB5 NoBackup

CB6 NoBackup

CB7 NoBackup


APPENDIX D: Expenditure Forecast and ReconciliationAc

tual

for

mos

t rec

ent

Fina

ncia

l Ye

ar ($

000)

Prev

ious

fo

reca

st fo

r Cu

rren

t Fi-

nanc

ial Y

ear

($00

0)

Fore

cast

Yea

r

For y

ear e

nded

2011

2012

2013

2014

2015

2016

2017

2018

2019

2020

2021

2022

CapitalExpen

diture:C

ustomer

Conn

ectio

n27

721

550

015

916

717

618

719

720

822

123

424

7

CapitalExpen

diture:System

Grow

th19

364

750

953

957

160

764

368

172

276

681

286

0

CapitalExpen

diture:A

ssetRe-

placem

enta

ndRen

ewal

2,48

23,19

724

1412

3561

188

172

784

266

914

3313

7410

29

CapitalExpen

diture:R

eliability,

Safetyand

Enviro

nmen

t97

91,45

325

3952

645

550

042

232

969

338

636

235

6

CapitalExpen

diture:A

ssetReloca-

tions

25-

050

00

00

00

00

Subtotal-Ca

pitalExpen

ditureon

AssetM

anagem

ent

3,95

65,51

25,96

22,50

91,80

42,16

41,97

92,04

92,29

22,80

62,78

22,49

2

Ope

ratio

nalExpen

diture:R

outin

ean

dPreven

tativ

eMainten

ance

3,25

83,73

736

0237

7138

2338

4439

6841

4042

9444

8947

0649

09

Ope

ratio

nalExpen

diture:R

efur-

bishmen

tand

Ren

ewalM

ainte-

nance

700

766

578

590

645

646

682

337

354

373

393

414

Ope

ratio

nalExpen

diture:Fau

ltan

dEm

ergencyMainten

ance

865

904

843

889

942

993

1051

1107

1170

1235

1307

1379

Subtotal-Ope

ratio

nalExpen

di-

tureonAssetM

anagem

ent

4,82

35,40

75,02

35,25

05,41

05,48

35,70

15,58

45,81

86,09

76,40

66,70

2

TotalD

irectExpen

ditureonDistri-

butio

nNetwork

8,77

910

,919

10,985

7,75

97,21

47,64

77,68

07,63

38,11

08,90

39,18

89,19

4

Overhea

dtoUnd

ergrou

ndCon

-versionExpe

nditu

re21

--

--

--

--

--

-

APPENDIXD:EXPENDITUREFORECASTANDRECONCILIATION 323

APPENDIX E: Glossary of TermsAAAC:AllAluminiumAlloyConductor-Usedasbareoverheadconductorforprimaryandsecondarydistribution.Designedutilizingahighstrengthaluminumalloytoachieveahighstrength-to-weightratio;affordsbettersagcharacteristics.AluminumalloygivesAAAChigherresistancetocorrosionthanACSR.

AAC:AllAluminiumConductor-Compactstrandconductorforuseinbareoverheadapplicationsorforusewithweather-resistantcoveringsorinsulationsisalsoavailable.

ACSR:AluminiumConductorSteelReinforced-Usedasbareoverheadtransmissioncableandasprimaryandsecondarydistributioncable.ACSRoffersoptimalstrengthforlinedesign.Variablesteelcorestrandingenablesdesiredstrengthtobeachievedwithoutsacrificingampacity.

Ampere(A):unitofelectricalcurrentflow,orrateofflowofelectrons.

AMP:AssetManagementPlan

CAIDI:aninternationalindexwhichmeasurestheaveragedurationofaninterruptiontosupplyforconsumersthathaveexperiencedaninterruption.Usuallycalculatedonaperannumbasis.

CAIDI=Sumof(numberofinterruptedconsumersxinterruptionduration)

Sumof(numberofinterruptedconsumers)

CapacityUtilisation:a ratiowhichmeasures theutilisationof transformers in thenetwork.Calculatedas themaximumdemandexperiencedonanelectricitynetworkinayeardividedbythetransformercapacityon

thatnetwork.

CircuitBreaker(CB):adevicewhichdetectsexcessivepowerdemandsinacircuitandcutsoffpowerwhentheyoccur.Nearlyalloftheseexcessivedemandsarecausedbyafaultofsomedescriptiononthenetwork.Intheurbannetwork,wheremostoftheseCBsare,theydonotattemptarecloseafterafaultastheLCBsdoontheruraloverheadnetwork.

ContinuousRating:theconstantloadwhichadevicecancarryatratedprimaryvoltageandfrequencywithoutdamagingand/oradverselyeffectingitcharacteristics.

Conductor:isthe‘wire’thatcarriestheelectricityandincludesoverheadlineswhichcanbecovered(insulated)orbare(notinsulated),andundergroundcableswhichareinsulated.

Actual for most recent

Financial Year ($000)

Previous forecast for Recent Fi-

nancial Year ($000)

% Variance

CapitalExpenditure:CustomerConnection 277 204 35.8%

CapitalExpenditure:SystemGrowth 193 535 -63.9%

CapitalExpenditure:AssetReplacementandRenewal 2,482 3,139 -20.9%

CapitalExpenditure:Reliability,SafetyandEnvironment 979 1,778 -44.9%

CapitalExpenditure:AssetRelocations 25 - Notdefined

Subtotal - Capital Expenditure on Asset Management 3,956 5,656 -30.1%

OperationalExpenditure:RoutineandPreventativeMaintenance 3,258 3,313 -1.7%

OperationalExpenditure:RefurbishmentandRenewalMaintenance 700 1,061 -34.0%

OperationalExpenditure:FaultandEmergencyMaintenance 865 875 -1.1%

Subtotal - Operational Expenditure on Asset Management 4,823 5,249 -8.1%

TotalDirectExpenditureonDistributionNetwork 8,779 10,905 -19.5%


Current:themovementofelectricitythroughaconductor,measuredinamperes(A).

DCF:DiscountedCashFlow-Methodforevaluatingprofitabilityofaninvestmentdecision.

DDO:DominionDropoutfuseusedonoverheadlinestoprovideapointofisolationandprotectionfordistributionsubstationsandfeeders.

DGA:DissolvedGasAnalysis-Testcarriedoutontransformeroilqualitytomeasurethelevelsofdissolvedgassesintheoil,thisgivesanindicationoftransformercondition.

DistributionSubstation:iseitherabuilding,akiosk,anoutdoorsubstationorpolesubstationtakingitssupplyat11kVanddistributingat400V.

DistrictSubstation:amajorbuildingsubstationand/orswitchyardwithassociatedhighvoltagestructurewhereeither;voltageistransformedfrom66or33kVto11kV,twoormoreincoming11kVfeedersfromagridexitpointareredistributedorarippleinjectionplantisinstalled.Sometimesknownasazonesubstation.

ELB:ElectricityLinesBusinessasdefinedbytheCommercecommissionandexcludingTranspower.

EPDM: Ethylene Propylene Diene Monomer rubber is used on dead end insulators. It exhibits satisfactorycompatibility with fireproof hydraulic fluids, ketones, hot and cold water, and alkalis, and unsatisfactorycompatibilitywithmostoils, gasoline, kerosene, aromaticandaliphatichydrocarbons,halogenated solvents,andconcentratedacids.

Fault Current:thecurrentfromtheconnectedpowersystemthatflowsinashortcircuitcausedbyafault.

Feeder:aphysicalgroupingofconductorsthatoriginatefromadistrictsubstationcircuitbreaker.

Flashover:adisruptivedischargearoundoroverthesurfaceofaninsulator.

Frequency:onACcircuits,thedesignatednumberoftimespersecondthatpolarityalternatesfrompositivetonegativeandbackagain,expressedinHertz(Hz)

Fuse: adevice thatwillheatup,meltandelectricallyopen thecircuitafteraperiodofprolongedabnormalcurrentflow.

GIS:GraphicalInformationSystemusedbyWestpowertoshowthephysicallocationofassetsintheirnetworkandisusedasatoolwiththeAssetWorksManagementSystem.

Gradient, Voltage:thevoltagedrop,orelectricaldifference,betweentwogivenpoints.

Grid Exit Point (GXP):apointwhereOrion’snetworkisconnectedtoTranspower’stransmissionnetwork.

Harmonics (Wave Form Distortion):changesanACvoltagewaveformfromsinusoidaltocomplexandcanbecaused by network equipment and equipment owned by consumers including electricmotors or computerequipment.

High Voltage:voltageexceeding1,000volts(1kV),inOrion’scasegenerally11kV,33kVor66kV.

Insulator:supportsliveconductors,ismadefrommaterialwhichdoesnotallowelectricitytoflowthroughit.

kVA: thekVA,orKilovolt-ampere,output ratingdesignates theoutputwhicha transformercandeliver foraspecifiedtimeatratedsecondaryvoltageandratedfrequency.

Line Circuit Breaker (LCB):acircuitbreakermountedonanoverhead linepolewhichquicklycutsoffpowerafterafaultsothatnopermanentdamageiscausedtoanyequipment.Itswitchespowerbackonafterafewsecondsandifthecauseofthefaulthasgone(eg.abranchhasblownoffaline)thenthepowerwillstayon.Iftheoffendingitemisstilltherethenpowerwillbecutagain.Thiscanhappenuptothreetimesbeforepowerwillstayoffuntilthefaultrepaired.SometimesaLCBisknownasarecloser.

Low Voltage:voltagenotexceeding1,000volts,generally230or400volts.

APPENDIXD:EXPENDITUREFORECASTANDRECONCILIATION 325

Maximum Demand:themaximumdemandforelectricity,atanyonetime,duringthecourseoftheyear.

MOCHED:Majoroutagecausinghugeeconomicdamage.

Network Deliveries:totalenergysuppliedtoournetworkthroughTranspower’sgridexitpoints,usually

measuredasenergysuppliedoverthecourseofayear.

Outage:aninterruptiontothesupplyofelectricity.

Proven Voltage Complaint:acomplaintfromaconsumerconcerningadisturbancetothevoltageoftheirsupplywhichhasproventobecausedbythenetworkcompany.

PILCSWA:FormofCableconstruction-PaperInsulatedLeadCoveredSteelWireArmouredcable.

ROI:ReturnonInvestment-financialratioforexpectedreturnforagiveninvestmentusuallyexpressedasapercentageperyear.

Ripple Control System:asystemusedtocontroltheelectricalloadonthenetworkby,forexample,switchingdomesticwaterheaters,orbysignalinglargeusersofahighpriceperiod.Alsousedtocontrolstreetlights.

RTU (Remote Terminal Unit):AnRTU isadevice installedata remote location thatcollectsdata,codes thedataintoaformatthatistransmittableandtransmitsthedatabacktoacentralstation,ormaster.ARTUalsocollectsinformationfromthemasterdeviceandimplementsprocessesthataredirectedbythemaster.RTUsareequippedwithinputchannelsforsensingormetering,outputchannelsforcontrol,indicationoralarmsandacommunicationsport.

SAIDI:SystemAverageInterruptionDurationIndex;aninternationalindexwhichmeasurestheaveragedurationofinterruptionstosupplythataconsumerexperiencesinagivenperiod.

SAIDI=Sumof(numberofinterruptedconsumersxinterruptionduration)

Totalnumberofconnectedconsumers

SAIFI:SystemAverageInterruptionFrequencyIndex;aninternationalindexwhichmeasurestheaveragenumberofinterruptionsthataconsumerexperiencesinagivenperiod.

SAIFI=Sumof(numberofinterruptedconsumers)= SAIDI

Totalnumberofconnectedconsumers SAIFI

SCADA:SystemControlandDataAcquisition.

Transformer:adevicethatchangesvoltageuptoahighervoltageordowntoalowervoltage.

Transpower:thestateownedenterprisethatoperatesNewZealand’stransmissionnetwork.Transpowerdeliverselectricityfromgeneratorstovariousnetworksaroundthecountry.

Voltage:electricpressure;theforcewhichcausescurrenttoflowthroughanelectricalconductor.

VoltageRegulator:anelectricaldevicethatkeepsvoltagewhichissuppliedtoconsumersataconstant level,regardlessofloadfluctuations.

XLPE:CrosslinkedPolyethylene-typeofcableinsulationXLPEcontainscross-linkbondswhichareintroducedintothepolymerstructure,changingthethermoplasticintoanelastomer.XLPE-insulatedcableshavearatedmaximumconductortemperatureof90°Candanemergencyratingofupto140°C,dependingonthestandardusedtorateXLPE-insulatedcables.CablesinsulatedwithXLPEalsohaveaconductorshort-circuitratingof250°C.XLPEhasexcellentdielectricpropertiesmakingitusefulforalargerangeofvoltageapplicationsfrom600Vto500kV.

ZoneSubstation:ZoneSubstationsareusedtotransformpowerfromtransmissionandsub-transmissionvoltagesof33kVandhigherdowntoWestpower’sstandarddistributionvoltageof11kV.