chapter 8 hydro energy · 2020. 9. 30. · chapter 8 hydro energy 8.1 summary key messages •...
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Chapter 8Hydro Energy
8.1Summary
K E y m E s s a g E s
• Hydroelectricityisamatureelectricitygenerationtechnologyandanimportantsourceofrenewableenergy.
• Hydroelectricityisasignificantenergysourceinalargenumberofcountries,althoughitscurrentshareintotalprimaryenergyconsumptionisonly2.2percentgloballyand0.8percentinAustralia.
• HydroelectricityiscurrentlyAustralia’smajorsourceofrenewableelectricitybutthereislimitedpotentialforfuturefurtherdevelopment.
• WateravailabilityisakeyconstraintonfuturegrowthinhydroelectricitygenerationinAustralia.
• FuturegrowthinAustralia’shydroelectricitygenerationwillbeunderpinnedbythedevelopmentofsmallscalehydroelectricityfacilitiesandefficiencygainsfromtherefurbishmentoflargescalehydroplants.
• TheshareofhydroinAustralia’stotalelectricitygenerationisprojectedtofalltoaround3.5percentin2029–30.
8.1.1Worldhydroenergyresourcesandmarket• Globaltechnicallyfeasiblehydroenergypotential
isestimatedtobearound16500TWhperyear.
• Worldhydroelectricitygenerationwas3078TWhin2007,andhasgrownatanaverageannualrateof2.3percentsince2000.
• Hydroenergyisthelargestsourceofrenewableenergy,andcurrentlycontributesnearly16percentofworldelectricityproduction.
• IntheOECDregion,hydroelectricitygenerationisprojectedbytheIEAtoincreaseatanaverageannualrateofonly0.7percentbetween2007and2030,mainlyreflectinglimitedundevelopedhydroenergypotential.
• Innon-OECDcountries,hydroelectricitygenerationisprojectedbytheIEAtoincreaseatanaverageannualrateof2.5percentbetween2007and2030,reflectinglarge,undevelopedpotentialhydroenergyresourcesinmanyofthesecountries.
8.1.2Australia’shydroenergyresources• Australia’stechnicallyfeasiblehydroenergy
potentialisestimatedtobearound60TWhperyear.
• Australiaisthedriestinhabitedcontinentonearth,withover80percentofitslandmassreceivinganannualaveragerainfalloflessthan600mmperyearand50percentlessthan300mmperyear.
• Highvariabilityinrainfall,evaporationratesandtemperaturesoccursbetweenyears,resultinginAustraliahavingverylimitedandvariablesurfacewaterresources.
• Australiacurrentlyhas108operatinghydroelectricpowerstationswithtotalinstalledcapacityof7.8GW(figure8.1).
8.1.3KeyfactorsinutilisingAustralia’shydroenergyresources• Potentialforthedevelopmentofnewlargescale
hydroelectricityfacilitiesinAustraliaislimited.However,theupgradeandrefurbishmentofexistinghydroelectricityinfrastructurewillincreaseefficiencyandextendthelifeoffacilities.
• ThereispotentialforsmallscalehydroelectricitydevelopmentsinAustralia,andthisislikelytobeanimportantsourceoffuturegrowthincapacity.
• Wateravailability,competitionforscarcewaterresources,andbroaderenvironmentalfactorsarekeyconstraintsonfuturegrowthinAustralianhydroelectricitygeneration.
8.1.4Australia’shydroelectricitymarket• In2007–08,Australia’shydroelectricityuse
represented0.8percentoftotalprimaryenergyconsumptionand4.5percentoftotalelectricitygeneration.Hydroelectricityusehasdeclinedonaverageby4.2percentperyearbetween1999–00and2007–08,largelyasaresultofanextendedperiodofdrought.
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Figure 8.1 MajorAustralianoperatinghydroelectricfacilitieswithcapacityofgreaterthan10MWsource: GeoscienceAustralia
• In2007–08,hydroelectricitywasmainlygeneratedintheeasternstates,includingTasmania(57percentoftotalelectricitygeneration),NewSouthWales(21percent),Victoria(13percent)andQueensland(8percent).
%
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1999-00 2001-02 2003-04 2005-06 2007-08 2029-30
Electricity generation(TWh)
AERA 8.2
Share of total electricitygeneration (%)
Figure 8.2 Australia’shydroelectricitygenerationto2029–30source: ABARE2009a,2010
• InABARE’slatestlong-termenergyprojectionsthatincludetheRenewableEnergyTarget,a5percentemissionsreductiontargetandothergovernmentpolicies,hydroelectricitygenerationisprojectedtoincreasefrom12TWhin2007–08to13TWhin2029–30,representinganaverageannualgrowthrateof0.2percent(figure8.2).
• Theshareofhydrointotalelectricitygenerationisprojectedtofallto3.5percentin2029–30.
• Hydroenergyisexpectedtobeovertakenbywindastheleadingrenewablesourceofelectricitygenerationduringtheoutlookperiod.
8.2Backgroundinformationandworldmarket8.2.1DefinitionsHydroelectricityiselectricalenergygeneratedwhenfallingwaterfromreservoirsorflowingwaterfromrivers,streamsorwaterfalls(runofriver)ischannelledthroughwaterturbines.Thepressureoftheflowingwaterontheturbinebladescausestheshafttorotateandtherotatingshaftdrivesanelectricalgeneratorwhichconvertsthemotionoftheshaftintoelectricalenergy.Mostcommonly,waterisdammedandthe
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CHAPTER 8: HYDRO ENERGY
flowofwateroutofthedamtodrivetheturbinesiscontrolledbytheopeningorclosingofsluices,gatesorpipes.Thisiscommonlycalledpenstock.
Hydropoweristhemostadvancedandmaturerenewableenergytechnologyandprovidessomelevelofelectricitygenerationinmorethan160countriesworldwide.Hydroisarenewableenergysourceandhastheadvantagesoflowgreenhousegasemissions,lowoperatingcosts,andahighramprate(quickresponsetoelectricitydemand).
Hydroelectricityhasbeenusedinsomeformsincethe19thcentury.Themaintechnologicaladvantageofhydroelectricityisitsabilitytobeusedforeitherbaseorpeakloadelectricitygeneration,orboth.Inmanycountries,hydroisusedforpeakloadgeneration,takingadvantageofitsquickstart-upanditsreliability.Hydroelectricityisarelativelysimplebuthighlyefficientprocesscomparedwithothermeansofgeneratingelectricity,asitdoesnotrequirecombustion.
Box 8.1 HyDROElECTRICITyTECHNOlOGIES
Hydroelectricity generationTheenergycreateddependsontheforceorstrengthofthewaterflowandthevolumeofwater.Asaresult,thegreaterthedifferencebetweentheheightofthewatersource(head)andtheheightoftheturbineoroutflow,thegreaterthepotentialenergyofthewater.Hydropowerplantsrangefromverysmall(10MWorless)toverylargeindividualplantswithacapacityofmorethan2000MWandvastintegratedschemesinvolvingmultiplelargehydropowerplants.Hydropowerisasignificantsourceofbaseloadand,increasingly,peakloadelectricityinpartsofAustraliaandoverseas.
Riverspotentiallysuitableforhydropowergenerationrequirebothadequatewatervolumethroughriverflows,whichisusuallydeterminedbymonitoringusingstreamgauges,andasuitablesitefordamconstruction.InAustraliavirtuallyallhydropowerisproducedbystationsatwaterstoragescreatedbydamsinmajorrivervalleys.Manyhavefacilitiestopumpwaterbackintohigherstoragelocationsduringoff-peaktimesforre-useinpeaktimes.Insomecases,thehydroplantcanbebuiltonanexistingdam.Thedevelopmentofahydroresourceinvolvessignificanttimeandcostbecauseofthelargeinfrastructurerequirements.Thereisalsoarequirementforextensiveinvestigationoftheenvironmentalimpactofdammingtheriver.Thisgenerallyinvolvesconsiderationoftheentirecatchmentsystem.
Pumped storage hydroelectricitystoreselectricityintimesoflowdemandforuseintimesofhighdemandbymovingwaterbetweenreservoirs.Itiscurrentlytheonlycommercialmeansofstoringelectricityoncegenerated.Byusingexcesselectricitygeneratedintimesoflowdemandtopumpwaterintohigherstorages,theenergycanbestoredandreleasedbackintothelowerstorageintimesofpeakdemand.Pumped-storagesystemscanvarysignificantlyincapacitybutcommonlyconsistoftworeservoirssituatedtomaximisethedifferenceintheirlevelsandconnectedbyasystemofwaterwayswithapumping-generatingstation.Theturbinesmaybereversibleandusedforbothpumpingandgeneratingelectricity.
Pumpedstoragehydroelectricityisthelargest-
capacityformofgridenergystoragewhereitcanbeusedtocovertransientpeaksindemandandtoprovideback-uptointermittentrenewableenergysourcessuchaswind.Newconceptsinpumped-storageinvolvewindorsolarenergytopumpwatertodamsasheadstorage.
mini hydro schemesaresmall-scale(typicallylessthan10MW)hydroelectricpowerprojectsthattypicallyservesmallcommunitiesoradedicatedindustrialplantbutcanbeconnectedtoanelectricitygrid.SomesmallhydroschemesinNorthAmericaareupto30MW.Thesmallesthydroplantsoflessthan100kWaregenerallytermedmicrohydro.Minihydroschemescanbe‘run-of-river’,withnodamorwaterstorage(seebelow),ordevelopedusingexistingornewdamswhoseprimarypurposeislocalwatersupply,riverandlakewater-levelcontrol,orirrigation.Minihydroschemestypicallyhavelimitedinfrastructurerequiringonlysmallscalecapitalworks,andhencehavelowconstructioncostsandasmallerenvironmentalimpactthanlargerschemes.Smallscalehydrohashadhighrelativecosts($perMW)butisbeingconsideredbothforruralelectrificationinlessdevelopedcountriesandfurtherhydrodevelopmentsinOECDcountries,oftensupportedbyenvironmentalpoliciesandfavourabletariffsforrenewableenergy(Paish2002).MostrecenthydropowerinstallationsinAustralia,especiallyinVictoria,havebeensmall(mini)hydrosystems,commencingwiththeThompsonprojectin1989.
Run-of-river systemsrelyonthenaturalfall(head)andflowoftherivertogenerateelectricitythroughpowerstationsbuiltontheriver.largerun-of-riversystemsaretypicallybuiltonriverswithconsistentandsteadyflow.Theyaresignificantinsomeoverseaslocations,notablyCanadaandtheUnitedStates.Minirun-of-riverhydrosystemscanbebuiltonsmallstreamsorusepipedwaterfromriversandstreamsforlocalpowergeneration.Run-of-riverhydroplantscommonlyhaveasmallerenvironmental‘footprint’thanlargescalestoragereservoirs.ThelowerDerwentandMerseyForthhydrodevelopmentsinTasmania,forexample,eachcomprisingsixpowerstationsupto85MWcapacity,usetributaryinflowsandsmallstoragesinastep-likeseries.
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Processing, Transport,End Use Market
StorageResources Exploration
AERA 8.3
Industry
Commercial
Residential
Domesticmarket
Development andProduction
Developmentdecision
ElectricityGeneration
Project
Resourcedefinition andsite selection
Storage
Figure 8.3 Australia’shydroenergysupplychainsource: ABAREandGeoscienceAustralia
Hydroelectricitygenerationisoftenconsideredamaturetechnologywithlimitedscopeforfurtherdevelopment.Plantscanbebuiltonalargeorsmallscale,eachwithitsowncharacteristics:
• Large scale hydroelectricity plantsgenerallyinvolvethedammingofriverstoformareservoir.Turbinesarethenusedtocapturethepotentialenergyofthewaterasitflowsbetweenreservoirs.Thisisthemosttechnologicallyadvancedformofhydroelectricitygeneration.
• small scale hydroelectricity plants,includingmini(lessthan5MW),micro(lessthan500kW)andpicofacilities,arestillatarelativelyearlystageofdevelopmentinAustralia,andareexpectedtobethemainsourceoffuturegrowthinhydroelectricitygeneration.Whilethereisnouniversallyaccepteddefinitionofsmallscalehydroelectricprojects,smallprojectsaregenerallyconsideredasthosewithlessthan10MWcapacity.
Withinthesetwobroadclassesofhydroelectricfacilities,therearedifferenttypesoftechnologies,includingpumpedstorageandrun-of-river(box8.1).Thetypeofsystemchosenwillbedeterminedbytheintendeduseoftheplant(baseorpeakloadgeneration),aswellasgeographicalandtopographicalfactors.Eachsystemhasdifferentsocialandenvironmentalimpactswhichmustbeconsidered.
Inthisreport,electricitygeneratedfromwaveandtidalmovements(coastalandoffshoresources)istreatedseparatelytothatgeneratedbyharnessingthepotentialenergyofwaterinriversanddams(onshoresources).Waveandtidalenergyisdiscussedinchapter11.
8.2.2HydroelectricitysupplychainFigure8.3isarepresentationofhydroelectricitygenerationinAustralia.InAustraliavirtuallyallhydroelectricityisproducedbystationsatwaterstoragescreatedbydamsinmajorrivervalleys.Anumberhavefacilitiestopumpwaterbackintohigherstoragelocationsduringoff-peaktimesforre-useinpeaktimes.Electricitygeneratedbythewaterturbinesisfedintotheelectricitygridasbaseloadandpeakloadelectricityandtransmittedtoitsendusemarket.
8.2.3WorldhydroelectricitymarketHydroenergyisasignificantsourceoflowcostelectricitygenerationinawiderangeofcountries.Atpresent,productionislargelyconcentratedinChina,NorthAmerica,OECDEuropeandSouthAmerica.However,manyAfricancountriesareplanningtodeveloptheirconsiderablehydroenergypotentialtofacilitateeconomicgrowth.Worldhydroelectricitygenerationisprojectedtogrowatanaverageannualrateofaround2percentto2030,largelyreflectingtheincreaseduseofhydroelectricityindevelopingeconomies.
ResourcesMostcountrieshavesomepotentialtodevelophydroelectricity.Therearethreemeasurescommonlyusedtodefinehydroenergyresources:
• gross theoretical potential–hydroenergypotentialthatisdefinedbyhypothesisortheory,withnopracticalbasis.Thismaybebasedonrainfallorgeographyratherthanactualmeasurementofwaterflows.
• Technically feasible–hydroenergypotentialthatcanbeexploitedwithcurrenttechnologies.Thisissmallerthangrosstheoreticalpotential.
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• Economically feasible–technicallyfeasiblehydroenergypotentialwhichcanbeexploitedwithoutincurringafinancialloss.Thisisthenarrowestdefinitionofpotentialandthereforethesmallest.
Theworld’stotaltechnicallyexploitablehydroenergypotentialisestimatedtobearound16500TWhperyear(WEC2007).Regionswithhighprecipitation(rainfallormeltingsnow)andsignificanttopographicreliefenablinggoodwaterflowsfromhighertoloweraltitudestendtohavehigherpotential,whileregionsthataredrier,thatareflatordonothavestrongwaterflowshavelowerpotential.Asia,AfricaandtheAmericashavethehighestfeasiblepotentialforhydroelectricity(figure8.4).
China’shydroenergyresourcesarethelargestofanycountry.Chinaisestimatedtohaveatheoreticalpotentialofmorethan6000TWhperyear,approximatelydoublecurrentworldhydroelectricitygeneration,andeconomicallyfeasiblepotentialofmorethan1750TWhperyear(HydropowerandDams2009).Chinaisalsohometothelargestsinglehydroelectricityprojectintheworld,ThreeGorges.
Whencompleted,thissitewillhaveacapacityof22500megawatts.Itgeneratedalmost50TWhofelectricityin2006(representingonlyaround31percentcapacityutilisation),morethanthreetimesAustralia’stotalhydroelectricitygeneration.
InAfrica,theDemocraticRepublicoftheCongohasthehighesthydroenergypotential,whileNorway’spotentialresourcesarethehighestinWesternEurope.InSouthAmerica,thehighesthydroenergypotentialisinBrazil,whereitexceeds2200TWhperyear.OthercountrieswithsubstantialpotentialincludeCanada,Chile,Colombia,Ethiopia,India,Mexico,Paraguay,TajikistanandtheUnitedStates.Nevertheless,almostallcountrieshavesomehydroenergypotential.
Australia’stheoreticalhydroenergypotential(265TWhperyear)isconsideredtoberelativelysmall,ranking27thintheworld(figure8.5).Highrainfallvariability,lowaverageannualrainfallovermostofthecontinent,andhightemperaturesandevaporationrateslimittheavailabilityofsurfacewaterresources(WEC2007).
0
Total
Asia
South America
Europe
Africa
Oceania
10 000 20 000 30 000 0 000
TWh/year
North America
AERA 8.4
Gross theoreticalpotential
Technicallyfeasible
Economicallyfeasible
4
Figure 8.4 Worldhydroelectricitypotential,byregionsource: HydropowerandDams2009
0 1000 2000 4000 70003000 5000
TWh/year
China
United States
India
Brazil
Russian Federation
Canada
Indonesia
Peru
Congo
Columbia
Australia AERA 8.5
6000
Figure 8.5 Grosstheoreticalhydroelectricitypotential,majorcountries
source: HydropowerandDams2009
Table 8.1 Keyhydrostatistics
a
unit australia 2007–08
oECD 2008
World 2007
Primary energy consumption PJ 43.4 4654 11084
Shareoftotal % 0.8 2.0 2.2
Averageannualgrowth,from2000 % -4.2 -0.3 2.0
Electricity generation
Electricityoutput TWh 12 1293 3078
Shareoftotal % 4.5 12.2 15.6
Electricitycapacity GW 7.8 366.9 848.5
a Energyproductionandprimaryenergyconsumptionareidenticalsource: IEA2009a;ABARE2009a;HydropowerandDams2009
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Primary energy consumptionHydroelectricitygenerationhasbeengrowingglobally,reflectingitsincreasingpopularityindevelopingeconomiesasarelativelycheap,simpleandreliablesourceofenergy(figure8.6).
Hydroelectricitygenerationaccountedfor2.2percentoftotalprimaryenergyconsumptionin2007(table8.1).Worldhydroelectricityconsumptionhasgrownatanaverageannualrateof2percentbetween2000and2007.However,intheOECD,hydroelectricityconsumptionhasbeendecliningatanaverageannualrateof0.3percent.
ConsumptionofhydroelectricityhasalsodeclinedinAustraliaduetotheprolongedperiodofdrought,particularlyinNewSouthWalesandVictoria,thathasaffectedhydroelectricitygeneration.
Electricity generationHydroelectricityaccountedfor16percentofworldelectricitygenerationin2007.Hydroelectricity’sshareintotalelectricitygenerationhasdeclinedfrom22percentin1971to16percent(figure8.6),becauseofthehigherrelativegrowthofelectricitygenerationfromothersources.latinAmericancountriesaccountforthelargestproportionofhydroelectricitygeneration,followedbyOECDNorthAmerica.ThemostrapidgrowthinhydroelectricitygenerationhasbeeninChina,whichisnowthefourthlargestgenerator.ManyAfricaneconomiesarealso
developingtheirhydroenergypotential,andhave
becomeasourceofgrowth.
Totalinstalledhydroelectricitygenerationcapacityis
currentlyaround849GW,witharound158GWofnew
capacityunderconstructioninlate2008(Hydropower
andDams2009).Some25–30GWofnewlarge
scalehydroenergycapacitywereaddedin2008,
mostlyinChinaandIndia(Ren212009).Chinahas
theworld’slargestinstalledhydroelectricitycapacity
witharound147GW(17percentofworldcapacity),
followedbytheUnitedStates,Brazil,Canadaandthe
RussianFederation.Theseeconomiesaccountfor
halfoftheworld’sinstalledhydroelectricitygeneration
capacity.In2008therewerearound200large
(greaterthan60mhigh)damswithhydroelectricity
facilitiesunderconstruction.
Thetotalinstalledcapacityofsmallhydroenergyisestimatedtobeabout85GWworldwide(Ren212009).MostofthisisinChinawheresome4–6GWperyearhavebeenaddedforthepastseveralyears,butdevelopmentofsmallhydroplantshasalsooccurredinotherAsiancountries.
In2007,worldproductionofhydroelectricitywas3078TWh(around11000PJ).ThelargestproducerswereChina,Brazil,CanadaandtheUnitedStates(figure8.7a).Australiaranked31stintheworld.Hydroelectricityaccountedforalargeshareoftotal
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Latin America China OECD Pacific Middle East
Former Soviet Union Africa
OECD Europe Asia (ex China) Non-OECD Europe
Share of totalelectricity generation (%)
AERA 8.6
Figure 8.6 Worldhydrogenerationandshareoftotalelectricitygenerationsource: IEA2009a
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6
electricitygenerationinsomeofthesecountriesincluding,mostnotably,Norway(98percent),Brazil(84percent),Venezuela(72percent),Canada(58percent)andSweden(44percent)(figure8.7b).
0 400 00
TWh300 500
a) Electricity output
China
Brazil
Canada
United States
Russian Federation
Norway
India
Venezuela
Japan
Sweden
Australia
100 200
0
b) Share of total
China
Brazil
Canada
United States
Russian Federation
Norway
India
Venezuela
Japan
Sweden
Australia AERA 8.7
20 40 60 80 100
%Figure 8.7 Worldelectricitygenerationfromhydro,majorcountries,2007
source: IEA2009a
Hydroelectricitymeetsover90percentofdomesticelectricityrequirementsinanumberofothercountriesincluding:theDemocraticRepublicoftheCongo,Ethiopia,lesotho,Malawi,Mozambique,NamibiaandZambiainAfrica;Bhutan,Kyrgyzstan,laos,Nepal
andTajikistaninAsia;AlbaniaandNorwayinEurope;andParaguayinSouthAmerica(HydropowerandDams2009).
outlook for the world hydroelectricity marketIntheIEAreferencecaseprojections,worldhydroelectricitygenerationisprojectedtoincreaseto4680TWhin2030,atanaverageannualrateof1.8percent(table8.2).HydroelectricitygenerationisprojectedtogrowintheOECDatanaverageannualrateof0.7percentandinnon-OECDcountriesbyanaverageannualrateof2.5percent.
ThegrowthinhydroelectricitygenerationintheOECDisexpectedtocomefromutilisationofremainingundevelopedhydroenergyresources.Growthisalsoexpectedtooccurinsmall(includingminiandmicro)andmediumscalehydroelectricityplants.Improvementsintechnologymayalsoimprovethereliabilityandefficiencyand,hence,outputofexistinghydroelectricityplants,aswouldrefurbishmentofageinginfrastructure.
Innon-OECDcountries,growthisexpectedtobeunderpinnedbythecostcompetitivenessofhydroelectricitycomparedwithothermeansofelectricitygeneration.Muchofthegrowthisexpectedtobeinsmallscalehydroelectricity,althoughthereareplansinmanyAfricancountriestobuildlargescalehydroelectricitygenerationcapacity.GrowthisalsoexpectedtooccurinAsia,particularlyChina.
Theimplementationofglobalclimatechangepoliciesislikelytoencouragethedevelopmentofhydroelectricityasarenewable,lowemissionsenergysource.IntheIEA’s450climatechangepolicyscenario,theshareofhydroinworldelectricitygenerationisprojectedtoincreaseto18.9percentin2030,comparedwith13.6percentinitsreferencecase.FortheOECDregions,underthisscenario,theshareofhydrointotalelectricitygenerationisprojectedtoincreaseto13.5percentin2030comparedwith11.2percentinthereferencecase.
Table 8.2 IEAreferencecaseprojectionsforworldhydroelectricitygeneration
unit 2007 2030
oECD TWh 1258 1478
Shareoftotal % 12.2 11.2
Averageannualgrowth,2007–2030 % - 0.7
Non-oECD TWh 1820 3202
Shareoftotal % 19.9 15.2
Averageannualgrowth,2007–2030 % - 2.5
World TWh 3078 4680
Shareoftotal % 15.6 13.6
Averageannualgrowth,2007–2030 % - 1.8
source: IEA2009b
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8.3Australia’shydroenergyresourcesandmarket
8.3.1HydroenergyresourcesAustraliaisthedriestinhabitedcontinentonearth,withover80percentofitslandmassreceivinganannualaveragerainfalloflessthan600mmperyearand50percentlessthan300mmperyear(figure8.8).Thereisalsohighvariabilityinrainfall,evaporationratesandtemperaturesbetweenyears,resultinginAustraliahavingverylimitedandvariablesurfacewaterresources.OfAustralia’sgrosstheoreticalhydroenergyresourceof265TWhperyear,onlyaround60TWhisconsideredtobetechnicallyfeasible(HydropowerandDams2009).Australia’seconomicallyfeasiblecapacityisestimatedat30TWhperyearofwhichmorethan60percenthasalreadybeenharnessed(HydropowerandDams2009).
ThefirsthydroelectricplantinAustraliawasbuiltinlauncestonin1895.Australiacurrentlyhas108operatinghydroelectricpowerstationswithtotalinstalledcapacityof7806MW.ThesecoincidewiththeareasofhighestrainfallandelevationandaremostlyinNewSouthWales(55percent)
andTasmania(29percent)(figure8.9).TheSnowyMountainsHydro-electricScheme,withacapacityof3800MW,accountsforaroundhalfofAustralia’stotalhydroelectricitygenerationcapacitybutconsiderablylessofactualproduction.Therearealsohydroelectricityschemesinnorth-eastVictoria,Queensland,WesternAustralia,andamini-hydroelectricityprojectinSouthAustralia.Pumpedstorageaccountsforabout1490MW.
TheSnowyMountainsHydro-electricSchemeisoneofthemostcomplexintegratedwaterandhydroelectricityschemesintheworld.TheSchemecollectsandstoresthewaterthatwouldnormallyfloweasttothecoastanddivertsitthroughtrans-mountaintunnelsandpowerstations.ThewateristhenreleasedintotheMurrayandMurrumbidgeeRiversforirrigation.TheSnowyMountainsSchemecomprisessixteenmajordams,sevenpowerstations(twoofwhichareunderground),apumpingstation,145kmofinter-connectedtrans-mountaintunnelsand80kmofaqueducts.TheSnowyMountainsHydro-electricSchemeprovidesaround70percentofallrenewableenergythatisavailabletotheeasternmainlandgridofAustralia,aswellasprovidingpeakloadpower(SnowyHydro2007).
Figure 8.8 AverageannualrainfallacrossAustraliasource: BureauofMeteorology
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ThehydroelectricitygenerationsysteminTasmaniacomprisesanintegratedschemeof28powerstations,numerouslakesandover50largedams.HydroTasmania,theownerofthemajorityofthesehydroelectricityplants,suppliesbothbaseloadandpeakpowertotheNationalElectricityMarket(NEM),firstlytoTasmaniaandthentheAustraliannetworkthroughBasslink,theunderseainterconnectorwhichrunsunderBassStrait.
8.3.2HydroelectricitymarketAustraliahasdevelopedmuchofitslargescalehydroenergypotential.ElectricitygenerationfromhydrohasdeclinedinrecentyearsbecauseofanextendedperiodofdroughtineasternAustralia,wheremosthydroelectricitycapacityislocated.HydroenergyisbecominglesssignificantinAustralia’sfuelmixforelectricitygeneration,asgrowthingenerationcapacityisbeingoutpacedbyotherfuels.
Primary energy consumptionAshydroenergyresourcesareusedtoproduceelectricity,whichisusedineithergridoroff-gridapplications,hydroenergyproductionisequivalenttohydroenergyconsumption.Hydroaccountedfor0.8
percentofAustralia’sprimaryenergyconsumptionin2007–08.Hydroelectricitygenerationdeclinedatanaverageannualrateof4.2percentbetween1999–2000and2007–08,theresultofaprolongedperiodofdrought.
Electricity generationIn2007–08,Australia’shydroelectricitygenerationwas12.1TWhor4.5percentoftotalelectricitygeneration(figure8.10).Overtheperiod1977–78to2007–08,hydroelectricitygenerationhastendedtofluctuate,reflectingperiodsofbeloworaboveaveragerainfall.However,theshareofhydrointotalelectricitygenerationhassteadilydeclinedoverthisperiodreflectingthehighergrowthofalternativeformsofelectricitygeneration.
TasmaniahasalwaysbeenthelargestgeneratorofhydroelectricityinAustralia,accountingfor57percentoftotalgenerationin2007–08(figure8.11).NewSouthWalesisthesecondlargest,accountingfor22percentoftotalelectricitygenerationin2007–08(sourcedmostlyfromtheSnowyMountainsHydro-electricScheme).Victoria,QueenslandandWesternAustraliaaccountfortheremainder.
Figure 8.9 MajorAustralianoperatinghydroelectricfacilitieswithcapacityofgreaterthan10MW.Numbersindicatesitesreferredtoinsection8.4.2
source: GeoscienceAustralia
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hTW
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15
10 %
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15
10
5
0
Electricity generation (TWh)
1977-78 1982-83 1987-88 1992-93 1997-98 2002-03 2007-08
Year
Share of total electricity generation (%)AERA 8.10
Figure 8.10 Australia’shydrogenerationandshareoftotalelectricitygeneration
source: ABARE2009a
New South Walesand ACT 21.9%
Tasmania56.9% Victoria
13.1%
Queensland7.7%
WesternAustralia
0.4% AERA 8.11
Figure 8.11 Australia’shydroconsumptionbystate,2007–08
source: ABARE2009a
Western Australia andSouth Australia 0.4%
Victoria8.9%
Tasmania New South Wales28.7% and ACT 53.7%
a) State
Queensland8.3%
>500 MW, 3
50-100MW, 16
<10 MW, 60
10-50MW, 20
AERA 8.12
b) Size
250-500MW, 5
100-250MW, 8
AERA 8.12
>500 MW, 3
50-100MW, 16
10-50MW, 20
<10 MW, 60
b) Size
100-250MW, 8
250-500MW, 5
New South Walesand ACT 53.7%
Tasmania28.7%
Queensland8.3%
Victoria8.9%
Western Australia andSouth Australia 0.4%
a) State
Figure 8.12 Installedhydrocapacitybystateandsize,2009source: GeoscienceAustralia
Installed electricity generation capacityAustraliahasonly3hydroelectricityplantswith
acapacityof500MWormore,allofwhicharelocated
intheSnowyMountainsHydro-electricScheme(figure
8.12).ThelargesthydroelectricityplantinAustralia
hasacapacityof1500MW,whichismid-sizedby
internationalstandards.Morethan75percent
ofAustralia’sinstalledhydroelectricitycapacityis
containedin16hydroelectricityplantswithacapacity
of100MWormore.Attheotherendofthescale,
therearesome60smallandmini-hydroelectricityplants(lessthan10MWcapacity)withacombinedcapacityofjustover150MW.
However,installedhydroelectricitygenerationcapacitydoesnotdirectlyreflectactualelectricitygeneration.ThesmallerinstalledcapacityinTasmaniaproducesmorethandoubletheoutputoftheSnowyMountainsHydro-electricScheme.Tasmaniaistheonlystatethatuseshydroelectricityasthemainmeansofelectricitygeneration.
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8.4Outlookto2030forAustralia’shydroenergyresourcesandmarketAlthoughbenefitingfromtheRenewableEnergyTargetandincreaseddemandforrenewableenergy,growthinAustralia’shydroelectricitygenerationisexpectedtobelimitedandoutpacedbyotherrenewables,especiallywindenergy.Futuregrowthinhydroelectricitygenerationcapacityislikelytocomemainlyfromtheinstallationofsmallscaleplants.WateravailabilitywillbeakeyconstraintonthefutureexpansionofhydroelectricityinAustralia.
8.4.1KeyfactorsinfluencingtheoutlookOpportunitiesforfurtherhydroelectricitygenerationinAustraliaareofferedbyrefurbishmentandefficiencyimprovementsatexistinghydroelectricityplants,andcontinuedgrowthofsmall-scalehydroelectricityplantsconnectedtothegrid.Hydroelectricitygenerationisalow-emissionstechnology,butfuturegrowthwillbeconstrainedbywateravailabilityandcompetitionforscarcewaterresources.
Hydroelectricity is a mature renewable electricity generation technology with limited scope for further large scale development in australiaMostofAustralia’sbestlargescalehydroenergysiteshavealreadybeendevelopedor,insomecases,arenotavailableforfuturedevelopmentbecauseofenvironmentalconsiderations.ThereissomepotentialforadditionalhydroenergygenerationusingthemajorriversofnorthernAustraliabut
thisislimitedbytheregion’sremotenessfrominfrastructureandmarketsandtheseasonalflowsoftherivers.
Upgrading and refurbishing ageing hydro infrastructure in australia will result in capacity and efficiency gainsManyofAustralia’shydroelectricpowerstationsarenowmorethan50yearsoldandwillrequirerefurbishmentinthenearfuture.Thiswillinvolvesignificantexpenditureoninfrastructure,includingthereplacementandrepairofequipment.Therefurbishmentofplantswillincreasetheefficiencyanddecreasetheenvironmentalimpactsofhydroelectricity.Furthertechnologydevelopmentswillbefocusedonefficiencyimprovementsandcostreductionsinbothnewandexistingplants(box8.2).
TheSnowyHydroSchemeiscurrentlyundergoingamaintenanceandrefurbishmentprocess,atacostofapproximatelyA$300million(inrealterms)oversevenyears(SnowyHydro2009).Themodernisationwillincludethereplacementofageingandhighmaintenanceequipment,increasingtheefficiencyandcapacityofturbines,andensuringthecontinuedreliableoperationofthecomponentsystemsofthescheme.
RefurbishmentofthepowerstationatlakeMargaret,Tasmania–oneofAustralia’soldesthydroelectricityfacilities(commissionedin1914)–commencedin2008.Themainobjectiveoftheprojectwastorepairtheoriginalwoodenpipeline,whichhaddeteriorated
Box 8.2HyDROElECTRICITyCOSTS
Hydroelectricity generation costs Themostsignificantcostindevelopingahydroresourceistheconstructionofthenecessaryinfrastructure.Infrastructurecostsincludethedamsaswellasthepowerplantitself.Buildingtheplantonanexistingdamwillsignificantlyreducecapitaloutlays.Costsincurredinthedevelopmentphaseofahydrofacilityinclude(Forouzbakhshet.al.2007):
• Civil costs–constructionofthecomponentsoftheprojectincludingdams,headponds,andaccessroads.
• Electro mechanical equipment costs–themachineryofthefacility,includingturbines,generatorsandcontrolsystems.
• Power transmission line costs –installationofthetransmissionlines.
Indirectcostsincludeengineering,design,supervision,administrationandinflationimpactsoncostsduringtheconstructionperiod.Constructionofsmallandmediumplantscantakebetween1to
6years,whileforlargescaleplantsitcantakeupto30years(forexample,theSnowyHydroSchemetook25yearstobuild).
ThecostsofbuildingAustralianhydroelectricitygenerationplantshavebeenvaried.TheSnowyHydroscheme,Australia’slargesthydroelectricityscheme,wasconstructedoveraperiodof25yearsatacostofA$820million(SnowyHydro2007).Australia’smostrecentmajorhydroelectricdevelopment,theBogongproject(site1,figure8.9),commencedconstructionin2006andwascommissionedinlate2009atacostofaround$234million.Theproject–whichincludesthe140MWBogongpowerstation,a6.9kmtunnel,headworksanda220kVtransmissionline–willprovidefastpeakingpower.Incomparison,theOrdRiverhydroelectricityscheme,whichwasbuiltontheexistingdamwhichcreatedlakeArgyleinWesternAustralia,wasconstructedatacostofA$75million(PacificHydro2009).Whilethisplantisrelativelysmall
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(30MW),itdemonstratesthepotentialreductioninconstructioncostswhereanexistingdamcanbeused.
Whilehydroelectricityhashighconstructionandinfrastructurecosts,ithasalowcostofoperationcomparedtomostothermeansofelectricitygeneration.IntheOECD,capitalcostsofhydroelectricplantsareestimatedatUS$2400perkW,andoperatingcostsareestimatedatbetweenUS$0.03andUS$0.04perkWh(IEA2008).Fornon-OECD
countries,capitalcostsareoftenbelowUS$1000
perkW.Theoperatingcostsofsmallhydroelectricity
facilitiesareestimatedatbetweenUS$0.02and
US$0.06perkWh.Operatingandcapitalcosts
dependonthesizeandtype(forexample,run-of-river)
ofplant,andwhetheritincludespumpedstorage
capabilities.Mosthydroelectricplantshavealifetime
ofover50years,duringwhichminimalmaintenance
orrefurbishmentisrequired,sotherelativelyhigh
capitalcostsareamortisedoveralongperiod.
(HydroTasmania2008).Theprojectinvolvedadditionalmaintenanceonthedam,minorupgradeofthemachines,aswellasreplacementofatransformer.Thisupgrade,completedinlate2009,costabout$14.7milliontogain8.4MWofcapacityatacapitalspendrateof$1.75millionperMW,considerablylessthanthecostsofnewplant.WorkhascommencedontheredevelopmentofthelowerMargaretPowerStation(HydroTasmania2009).
small scale hydro developments are likely to be an important source of future growth in australiaWiththeexceptionoftheBogongproject(seeProposeddevelopmentprojectsinsection8.4.2),mosthydroelectricityplantsinstalledinAustraliainrecentyearshavebeenminihydroschemes.Theseplantshavetheadvantageoflowerwaterrequirementsandasmallerenvironmentalimpactthanlargerschemes,especiallythosewithlargestoragedams.
AlthoughmostofAustralia’smostfavourablehydroelectricitysiteshavebeendeveloped,minihydroelectricityplantsarepotentiallyviableonsmallerriversandstreamswherelargedamsarenottechnicallyfeasibleorenvironmentallyacceptable.Theycanalsoberetro-fittedtoexistingwaterstorages.Atpresentminihydroplantsaccountforonlyaround2percentofinstalledhydrocapacity.Research,developmentanddemonstrationactivityislikelytoincreasethecostcompetitivenessofsmallscalehydroschemesinthefuture(box8.3).
surface water availability and competition for scarce water resources will be a key constraint to future hydro developments in australia Australiahasahighvariabilityofrainfallacrossthecontinent(figure8.8).Thismeansthatannualinflowstostoragescanvarybyupto50percentandseasonalvariationscanbeextreme.OngoingdroughtinmuchofsoutheasternAustraliahasseenasubstantialdeclineinwaterlevelsinthemajorstoragesinNewSouthWales(notablytheSnowyMountainsscheme),VictoriaandTasmaniaanddecliningcapacityfactorsforhydroelectricitystations.WaterlevelsinstoragesacrossAustraliahavedeclined
toanaverageofbelow50percentofcapacity(NationalWaterCommission2007).CloudseedinghasbeenusedintheSnowyMountainsandinTasmaniatoaugmentwatersupplies.
ClimatechangemodelssuggesttheoutlookforsoutheasternAustraliaisfordrierconditionswithreducedrainfallandhigherevaporation,andahigherfrequencyoflargestorms(BOM2009;IPPC2007;Batesetal.2008).Reducedprecipitationandincreasedevaporationareprojectedtointensifyby2030,leadingtowatersecurityproblemsinsouthernandeasternAustraliainparticular(Hennessyetal.2007).TheclimatechangeprojectionsfurtherexacerbatetheproblemofAustralia’sdryclimatewithlowandvariablerainfall,lowrunoffandunreliablewaterflowsandmeanthatthereisonlylimitedpotentialforfurthermajorhydrodevelopmentinmainlandAustralia.SomeofthispotentialislocatedintheriversinnorthernAustralia,butthisislimitedbytheinconsistencyofwaterflowsinthisregion(periodsoflowrainfallalongwithperiodsofflooding).
Competitionforwaterresourceswillalsoaffecttheavailabilityofwaterforhydroelectricitygeneration.Demandforwaterforurbanandagriculturalusesisprojectedtoincrease.Itislikelythattheseusesforscarcewaterresourceswilltakeprecedenceoverhydroelectricitygeneration.Generatorsfaceincreasingdemandstobalancetheirneedsagainsttheneedforgreaterwatersecurityforcitiesandmajorinlandtowns.Themaintenanceofenvironmentalflowstoensuretheenvironmentalsustainabilityofriversystemsbelowdamsisalsoanimportantfutureconsiderationwhichmayfurtherconstraingrowthofhydroelectricitygeneration.
WaterpoliciesmayalsoplayaroleinthefuturedevelopmentofhydroelectricityinAustralia.Policiesthatlimittheavailabilityofwatertohydroelectricitygenerators,restricttheflowofwaterintodams,requiregeneratorstoletwateroutofdams,orprioritisetheuseofwaterforagriculturecouldchangetheviabilityofmanyhydroelectricgenerators,andlimitfuturegrowth.TheextendeddroughtinmuchofAustraliahasledtowaterrestrictionsbeingputintoplaceinmostcapitalcities,andregulationoftheMurray-Darlingbasinriversystemshasstrengthened.
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CHAPTER 8: HYDRO ENERGY
Box 8.3TECHNOlOGyDEVElOPMENTSINHyDROElECTRICITy
Researchisbeingundertakentoimprove
efficiency,reducecosts,andtoimprovethe
reliabilityofhydroelectricitygeneration.There
aredifferentresearchneedsforsmallandlarge
scalehydro(table8.3).Smallhydropowerplants,
includingmicroandpicoplants,areincreasingly
seenasaviablesourceofpowerbecauseoftheir
lowerdevelopmentcostsandwaterrequirements,
andtheirlowerenvironmentalfootprint.Smallscale
hydropowerplantsrequirespecialtechnologies
toincreasetheefficiencyofelectricitygeneration
andtherebyminimiseboththeoperatingcosts
andenvironmentalimpactsofhydroelectricity
generation(ESHA2006).
Theenvironmentalimpactsofhydroelectricity
arealsobeinginvestigated,andwaystomitigate
theseimpactsdeveloped.Thisincludesthe
developmentofnewandimprovedturbines
designedtominimisetheimpactonfishandother
aquaticlifeandtoincreasedissolvedoxygeninthe
water.Theintroductionofgreaselessbearingsintheturbineswouldreducetheriskofpetroleumproductsenteringthewater,andisalsocurrentlybeinginvestigated(EERE2005).
Table 8.3 Technologyimprovementsforhydropower
Large hydro small hydro
Equipment Equipment low-headtechnologies, Turbineswithlessimpactincludingin-streamflow onfishpopulationsCommunicateadvances low-headturbinesinequipment,devicesand In-streamflowtechnologiesmaterials
operation and maintenance operation and maintenance Increasinguseof Developpackageplantsmaintenance-free requiringonlylimitedandremoteoperation operationandmaintenancetechnologies
Hybrid systems Wind-hydrosystemsHydrogen-assistedhydrosystems
source: IEA2008
8.4.2OutlookforhydroelectricitymarketHydroelectricityisprojectedtocontinuetobeanimportantsourceofrenewableenergyinAustraliaovertheoutlookperiod.
InABARE’slatestlong-termenergyprojectionsthatincludetheRenewableEnergyTarget,a5percentemissionsreductiontargetandothergovernmentpolicies(ABARE2010),hydroelectricitygenerationisprojectedtoincreaseonlyslightlybetween2007–08and2029–30,representinganaverageannualgrowthrateof0.2percent.In2029–30,hydroisprojectedtoaccountfor3.5percentofAustralia’stotalelectricitygeneration,and0.6percentofprimary
energyconsumption(figure8.13).Thepotentialforreturnofhydroelectricityoutputtopre-2006levelswillbestronglyinfluencedbyclimateandbywateravailability.
Proposed development projectsBasedonHydropowerandDams(2009),thereareseveralcurrenthydroprojectdevelopmentsinAustralia:
• A20MWhydroplantiscurrentlyunderconstructionattheDartmouthregulatingdaminVictoria(Site2,figure8.9).
• Thenextstageofredevelopmentofthe8.4MWlakeMargaretpowerstationinTasmaniahasbeenapprovedbytheboardofHydroTasmania(Site3,figure8.9).
• HydroTasmaniaConsultinghasbeenawardedacontracttosupplyandconstructsixminihydroplantsforMelbourneWaterwithatotalcapacityof7MW,producingupto40GWhperyear.
8.5ReferencesABARE(AustralianBureauofAgriculturalandResourceEconomics),2009a,AustralianEnergyStatistics,Canberra,August
ABARE,2009b,Majorelectricitydevelopmentprojects–Octoberlisting,Canberra,November
ABARE,2010,Australianenergyprojectionsto2029–30,ABAREresearchreport10.02,preparedfortheDepartmentofResources,EnergyandTourism,Canberra
GeoscienceAustralia,2009,mapofoperatingrenewableenergygeneratorsinAustralia,Canberra
%
4
3
2
1
0
5
6
7
Year
8
9
hTW
0
14
12
10
8
6
4
2
16
18
1999-00 2001-02 2003-04 2005-06 2007-08 2029-30
Electricity generation(TWh)
AERA 8.2
Share of total electricitygeneration (%)
Figure 8.13 Australia’shydroelectricitygenerationto2029–30source: ABARE2009a,2010
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