FUI Stakeholder Group4th July 2008, Sellindge

IFA Overview,Performance Report 2007-8& Valve Replacement Project

Simon McVeighIFA Manager

• IFA Overview

• Performance Report 2007-8

• Valve Replacement Project

Interconnexion France-Angleterre

National Grid & Interconnectors

• 1500km (cabled under the St.Lawrence River) Sandy Pond HVDC transmission link connecting New England, USA and Quebec, Canada;

• 370km link (290km submarine) across the Bass strait between Tasmania and Victoria, Australia;

• 43km submarine cable system, to enhance electricity delivery to the island of Nantucket, off the Massachusetts coast;

• National Grid is assessing the feasibility with Elia of a submarine link between GB and Belgium.

Basslink – at the time the world’s longest subsea cable coming ashore in Tasmania

National Grid has a strong track record in developing and operating interconnector projects

Background

Original link• First steps to assess feasibility in 1948• Government approval 1957• 160MW link commissioned in 1961• Prone to damage from marine activity and withdrawn from service in 1982• Benefits of a link already established

Cross-Channel Link (later termed IFA)• Investigation into a suitable route• Development of new machines to

bury cables in the sea bed• Project cost £700m at 1981 prices• Half the cost of a 2GW power station

Scotland

Commissioned in 1986, the link is 70km in length, (45km sub-sea), consisting of 2 converter stations, 8 land cables and 4 submarine cable routes

England & Wales

France

2000MW High Voltage Direct Current (HVDC) link connecting the GB and French transmission systems

IFA Asset Overview

•Both converter stations can ‘rectify’ (AC→DC) or ‘invert’ (DC→AC) to allow import or export of power•Discrete asset ownership but jointly operated by National Grid and Réseau de Transport d'Electricité•Compatible but not identical equipment•No asset (capacity) redundancy

Converter Stations

Les MandarinsLes Mandarins

•High Voltage Direct Current (HVDC); ‘current source’ technology; low loss•Allows precise control of the magnitude and direction of the Direct Current flow between two very large synchronous Alternating Current power systems (GB, UCTE)•AC System frequencies are nominally the same (50Hz) but AC link not possible between 400kV systems for technical reasons

Submarine Operations

Contracts• Maritime Operations: LD Travocean• Submarine Cable Repair: Nexans

Standby• Equipment & spares at Dunkirk• Submersible co-owned, maintained by contractor• Fault estimation & ‘hold’ for survey• Fault location & ‘hold’ for vessel hire & mobilisation• Desktop review

• IFA Overview

• Performance Report 2007-8

• Valve Replacement Project

Interconnexion France-Angleterre

ETSO NACM Task Force

• Sub-group to Task Force led by E.On

• Several interconnections studied– IFA, IFB, IFD, P-Cz, D-P, D-DW, B-NI, D-NI, D-CH

• Analyse curtailments for 2006 CY data– Classified as caused by:

• Internal AC Network• Interconnector assets

Firmness Study on Interconnectors Draft Curtailment Data 2006

0

5

10

15

20

25

30

B-NL D-DW D-NL D-CH D-F P-Cz P-SL P-VE SL-P IFA

Interconnector Network

Annual Outages

Short-Notice Planned Outages

Unplanned Trips/Reductions

IFA Curtailment Commentary*

* Discrete curtailment events shown (not duration) Switching transitions 500MW / 1000MW not listed individually

AC Borders

Asset related maintenance/faults have not curtailed cross-border capacity because of

Security Standards (UCTE Handbook) therefore redundancy in interconnection capacity

IFA Performance Report 2007-8

• Mid-point in asset life after nearly 25 years operation

IFA Annual Availability (%)

94.6

93.0

93.9

90

91

92

93

94

95

96

97

98

99

100

2005-06 2006-07 2007-08

IFA Monthly Unavailability (%)Split RTE / NGIL

0

2

4

6

8

10

12

14

APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR

NGIL RTE

IFA Planned Outages 2007-8Split RTE / NGIL

0

1

2

3

4

5

Ou

tag

es >

(D-2

) no

tice

Joint RTE NGIL

IFA Unplanned Outages 2007-8Split RTE / NGIL

0

1

2

3

4

5

6

7

8

9

10

Ou

tag

es

< (

D-2

) n

oti

ce

RTE NGIL

Valve/Control System Related OutagesSplit RTE / NGIL

0

2

4

6

8

10

12

14

Pla

nn

ed

& U

np

lan

ne

d O

uta

ge

s

RTE Valves/Controls NGIL Valves/Controls Other Assets

• IFA Overview

• Performance Report 2007-8

• Valve Replacement Project

Interconnexion France-Angleterre

Joint feasibility study commenced 2005 to replace thyristor valves and controls with common designJoint contract for €70m (£56m) awarded to Areva 16th May 2008

Valve Replacement

Mid-life refurbishment: 25 yearsIdentical equipment will yield additional benefits in maintenance and supportDynamic frequency responseNesting of other mid-life work being assessed