North – South Interconnection

1. North – South Interconnection All Island Energy Market Forum 12th March 2004

2. Contents • Joint studies on North South Interconnection • All Island Dispatch Study • All Island Energy Market : Implications for interconnection ?

3. Investigation into further development of North South Interconnection ESBNG-NIE Joint Studies

4. Joint Studies - Presentation Structure • Objectives of Investigation • Overview of components • What limits interconnection transfer capacity? • Technical options under consideration • Emerging technical conclusions • Stakeholder and economic analysis • What happens next

5. Investigation Objectives • How could additional interconnector capacity for trading be provided? • Is the provision of additional interconnector capacity likely to be justified? • If it is justified, progress the project with the benefit of EU funding for feasibility studies

6. Overview Detailed route survey Environmental impact analysis Recommendation to proceed ? Technical Economic if yes Route Feasibility Stakeholder Analysis

7. Existing Interconnection Letterkenny 110kV Strabane TANDRAGEE Enniskillen 110kV 275kV Corraclassy LOUTH

8. For power flow in each direction, capacity is the minimum of Network Capacity Circuit overload or low voltage on NIE system or Interconnectors or ESB system System Separation Limit Loss of Louth Tandragee 275kV double circuit will split the system. At what transfer level is this unacceptable for NIE or ESB Stability Limit Risk of steady state oscillation on combined system Risk of transient stability problem on combined network What limits interconnection capacity?

9. Technical – Interconnector options being considered

10. Option 1:- Multiple 110kV Trillick Coolkeeragh Tandragee Lisdrum Newry Louth

11. Option 2:- Western 275kV interconnector Coolkeeragh Srananagh

12. Option 3:- Mid-country 275kV interconnector

13. Emerging Technical Conclusions • For the existing ESB/NIE interconnection, system separation limits power transfers in both directions. • Additional 275kV cross border interconnection would increase transfer levels (subject to economic considerations) • Some internal reinforcements also required to facilitate increased transfer levels. Both on ESB and on NIE side. (subject to economic considerations)

14. Emerging Technical Conclusions - Comment • Conventional wisdom is that power flow to NIE is limited by network constraints on the ESB system. • These do exist but system separation restricts power transfers to the same level. • Even if the network constraints on the ESB system are overcome, power transfer will still be limited by system separation.

15. Stakeholder and Economic Analysis

16. Assessing Benefits / Value • What benefits? • How assess / measure? • Liberalised Markets have many more stakeholders each with their interests and drivers. • Governments and Regulators • Asset owners • Generators • Demand customers • Large • Small • Energy traders • Market managers

17. Two Approaches • Economic • Quantify capacity benefits • Quantify trades • Assumptions critical • Scenarios • Wider Benefits • Stakeholder perceptions of trading opportunities • Stakeholder perceptions of customer benefits, security, market power, environment, political issues.

18. Emerging Conclusions – Stakeholder and Economic • Economic Studies are not yet complete. • Results from some scenarios show some small trading benefits • Other scenarios, which may erode these benefits, are being assessed • Stakeholder Analysis • Awaiting feedback from stakeholders • Report being prepared by consultants

19. What happens next • Draw different aspects of investigation together • Decide on way forward • If further interconnection recommended • Proposal to regulators\policy makers for approval • Need clear technical and economic case which will stand up to scrutiny by the planning authorities and if necessary, appeal and judicial review processes • Strong stakeholder support

20. All Island Dispatch Study

21. BACKGROUND • As part of the Ballymascanlon Process series of meetings, CER and OFREG requested that both TSO’s System undertake an All Island dispatch study. • Objective : Analyse Potential Energy Trading and Associated Economic Benefits for a sample year (2003) • No Interconnector Transfer Limits • Dispatch on merit order basis • Reserve on economic basis (no jurisdictional constraint)

22. Key Findings • Savings Minimal / Theoretical = 1.1% of dispatch cost in 2003 • Flows are predominantly from North to South • Savings in Spinning Reserve • Higher emissions with a joint dispatch. • Existing cross border co-operation is harnessing some of this potential saving. • Two balanced portfolios • developed to meet system requirements in both jurisdictions independently • dispatch cost savings with combined system are low as expected

23. All Island Energy Market: Implications for Interconnection?

24. Issues for consideration (1) • Does concept of interconnection disappear in an All Island Energy market? • Impact of market structure • Is the interconnector a boundary? • Technically the same problem will exist – loss of the 275kV Louth – Tandragee interconnectors will result in two separate systems. Implications of a split system in an all island market?

25. Issues for consideration (2) • Joint Transmission Planning • Co-ordination • Purpose • Ireland is not unique • Similar issues arise where markets cross jurisdictions • Nordel • Betta • Iberia • TSO’s considering what happens elsewhere - objective is to clarify implications for Irish situation

26. END