2009 Summer Outlook and Sable Island Offshore Energy Project Planned Outage

1. 2009 Summer Outlook and Sable Island Offshore Energy Project Planned Outage Reliability Committee meeting June 16, 2009 Michael Taniwha Director Operations

2. Overview 2008 Summer Review Major Transmission Projects Summer Action Plan Summer Operable Capacity Analysis Sable Island Offshore Energy Project (SOEP) Outage

3. 2008 Summer Review • Last summer’s temperatures generally cooler • Last summer’s peak 26,111 MW on June 10 • Previous all time peak load was 28,130 MW on August 2, 2006 • No OP4 actions required in summer period

4. Major Transmission Projects • Middletown - Norwalk 345 kV loop • Beseck – East Devon • East Devon – Singer • Singer – Norwalk • New 345/115 kV autos at Norwalk, Singer & East Devon • 1385 (Northport - Norwalk Cables) • 3163 Stoughton - K Street cable (3rd Boston cable) • Short-term LSM Project (May – June 2009) • Carver substation reconfiguration • 2nd 345/115 kV auto transformer • Looping 355 Pilgrim – Bridgewater 345 kV line into Carver

5. Summer Capacity Action Plan • Summer Capacity Outlook Communications • Transmission Owners • Master/Local Control Center (M/LCC) Heads • OP4 Contacts • Utilities, State Regulators, State Emergency Mgmt, FERC & NERC • NPCC/NERC • System Readiness • Verified with LCCs Critical Transmission Inspection/Maintenance Being Performed by Transmission Owners • Review Long Term Outage Schedule • Review/Monitor Generation Maintenance Progress/Schedules • Coordinating with Gas Transmission companies • Coordinating with NBSO on SOEP planned outage

6. Summer Capacity Action Plan (cont.) • Voltage Reduction Test • Completed April 28th • Review of Operating Procedures/Transmission Operating Guides • Emergency Procedures (OP4, OP6, OP7, OP21 & M/LCC2) • Area Transmission Operating Guides • Emergency Operations Training • ISO & Local Control Center Operators • Generator & Demand Resource Operators

7. ISO-NE Daily System Peak Load

8. What is this Summer Looking Like? • Summer 2009 Peak Load Exposure Forecast • Summer 50/50 reference forecast of 27,369 MW. The extreme, 90/10 summer peak load exposure forecast of 29,274 MW • Forecast includes 2009 adjustment for other passive demand resources (ODRs) ~ 500 MW. • Negative operable capacity margins for all peak load exposure weeks during the summer months of July and August using both the 50/50 and 90/10 load forecast are currently projected. However, operable capacity margin will change once next month capacity import transactions are known at the end of each month. • Generator planned outage requests during the peak load exposure weeks during July and August are not being approved per ISO New England Operating Procedure No. 5

9. Summer 2009 Operable Capacity Analysis

10. Possible Relief Actions Under OP4 Note: OP-4 Actions based on a 28,048 MW system load * Total Demand Response MW, including voluntary price response = 2,073 MW (voluntary price response = 82 MW)

11. Summer 2009 Operable Capacity Analysis 50/50 Forecast (Reference)

12. Summer 2009 Operable Capacity Analysis 90/10 Forecast (Extreme)

13. Sable Island Offshore Energy Project Planned Outage

14. Sable Offshore Energy Project (SOEP) – Planned Outage • SOEP commenced production in December 1999 • Regulatory permits require 10 year re-inspection • M&N Pipeline posted publically on April 21st information about the SOEP outage planned for August • Start date is early August • Outage is scheduled for approximately 20 days • M&N Pipeline is encouraging its customers to confirm alternate gas supply arrangements from the other 3 supply points available on the M&N system • Corridor Resource Supply – via McCully Pipeline interconnect • Portland Natural Gas Transmission System – direct interconnect • Canaport LNG supply – via Brunswick Pipeline interconnect

15. M&N Pipeline System Map

16. SOEP Outages – not the first time • SOEP and M&N Pipeline scheduled major planned outages last summer • 6/2/08 – 6/7/08 • 8/14/08 – 8/20/08 • SOEP has experienced numerous unplanned outages with some outages over multiple days

17. Planning Actions by ISO ISO has been in close communication with the major interstate Northeast pipeline operators regarding the SOEP outage ISO has also had discussions with the SOEP operator ExxonMobil regarding outage and the possibility of moving the SOEP outage ISO has been in contact with Repsol the Canaport operator to confirm the production commencement date ISO has been in close communication with NBSO regarding the SOEP outage and to ensure maximum NB-NE tie line availability

18. Impact of SOEP Outage • Based on this summer’s New England Operable Capacity Analysis the impact from the loss of all gas only generation supplied from the M&N Pipeline is manageable from the regional (NE system wide) perspective • 50/50 Operable Capacity Analysis is likely to be positive once August external ICAP transactions are known at the end of July • While 90/10 Operable Capacity Analysis could be slightly negative once August external ICAP transactions are known at the end of July, in this case any operating reserve deficiencies would be managed using OP4 actions

19. Impact of SOEP Outage (cont.) • Based on this summer’s generation requirements for transmission (GRT) analysis, it is likely that the impact from the loss of all gas only generation supplied from the M&N Pipeline is manageable from a Maine import perspective • The GRT analysis does not address localized concerns that may arise due to on-going reliability issues in Maine • Failure of generation to perform at SSCC may lead to greater deficiencies and additional concerns • OP4 actions would be required possibly up to action 12 under 90/10 peak load conditions to maintain reliability

20. Questions?