1. Developing an Adequacy Metric Resource Adequacy Forum Technical Subcommittee Meeting October 16, 2009

2. October 16, 2009Resource Adequacy Technical Committee 2 Outline Current Adequacy Metric: LOLP The Problem with LOLP LOLP Subcommittee Suggestions Next Steps

3. Current NW Resource Adequacy Metric: LOLP

4. October 16, 2009Resource Adequacy Technical Committee 4 Cold Hydro Limited GENESYS SimulationIllustrative Example Only

5. October 16, 2009Resource Adequacy Technical Committee 5 What do we Count? Ideally, we count “significant” events (those that we want to avoid) Energy threshold (or contingency resource) is 1,200 MW for one day or 28,800 MW- hours from Dec-Mar Capacity threshold (or contingency resource) is 3,000 MW in any hour from Dec-Mar and from Jun-Sep

6. October 16, 2009Resource Adequacy Technical Committee 6 Curtailment Events (Peaking problems and energy shortages) Each event has a peak and duration.

7. October 16, 2009Resource Adequacy Technical Committee 7 Curtailment Events (non-events not shown)

8. October 16, 2009Resource Adequacy Technical Committee 8 Loss of Load Probability Simulated 300 winters (December through March) Out of 300 winters, 15 had an average curtailment greater than 10 MW-seasons, which means that the Winter Loss of Load Probability (LOLP) = 15/300 = 5 percent

9. October 16, 2009Resource Adequacy Technical Committee 9 Energy LOLP (Sum of Curtailed Energy Dec-Mar)

10. October 16, 2009Resource Adequacy Technical Committee 10 LOLP vs. Contingency Resource 28,800 MW-Hrs LOLP = 4% 10,000 MW-Hrs LOLP = 12%

11. October 16, 2009Resource Adequacy Technical Committee 11 Study Statistics Number of Simulations (Games)50 Hours in the Dec-Mar period2,904 Total number of hours simulated145,200 Number of games with at least one hour of curtailment 18 Number of curtailment hours (over all games)275 Number of curtailment events83 Average magnitude per event1,953 MW- hrs Average duration per event3.4 hours Average number of events per game with curtailments 4.6

12. October 16, 2009Resource Adequacy Technical Committee 12 LOLP Type Statistics Types of events No. of Games LOLP (%) At least 1 hour of curtailment1836 Total curtailment > 28,800 mw-hrs24 Total curtailment > 10,000 mw-hrs612 At least one event > 4 hours1326 At least one event > 4,000 mw-hrs918 At least one event > 4-hour & > 4,000 mw-hrs510 At least five hours with curtailment > 1,000 mw510 At least ten hours with curtailment > 1,000 mw24 At least one hour with curtailment > 1,000 mw1122

13. The Problem with LOLP

14. October 16, 2009Resource Adequacy Technical Committee 14 Potential Problem with LOLP Same LOLP – Bigger Magnitude

15. October 16, 2009Resource Adequacy Technical Committee 15 Potential Problem with LOLP Lower LOLP – Bigger Magnitude

16. October 16, 2009Resource Adequacy Technical Committee 16 Are LOLP curves well behaved? (i.e. do they cross?) LOLP Magnitude

17. October 16, 2009Resource Adequacy Technical Committee 17 LOLP vs. Magnitude (If this relationship were dependable, the magnitude of the problem could be estimated by knowing the LOLP)

18. LOLP Subcommittee Report and Recommendations

19. October 16, 2009Resource Adequacy Technical Committee 19 LOLP Subcommittee Report Clearly define all reserve requirements –Operating reserves –Planning reserves –Wind integration reserves Determine which reserve curtailments count toward LOLP Add temperature-correlated wind as a random variable Decouple temperature and water condition Define a “contingency” resource for each month of the year instead of defining threshold events Record curtailment events across all months of the year Consider using other adequacy metrics Continue to assess climate change impacts

20. October 16, 2009Resource Adequacy Technical Committee 20 LOLP Review Status Reserves –Work being done by PNUCC committee Temperature-correlated wind –BPA working on a test data set Decouple temp and water –Done Contingency resource –Work needs to be assigned Annual metric –Not yet started Other metrics –BPA draft methodology –PSRI review Climate change –Ongoing

21. Next Steps

22. October 16, 2009Resource Adequacy Technical Committee 22 Possible Modifications to the Current Method Replace LOLP with an alternative metric Use LOLP in conjunction with an alternative adequacy metric Use LOLP in conjunction with the magnitude of the most severe event (or an average of the worst 10% of events)

23. October 16, 2009Resource Adequacy Technical Committee 23 Examples of Other Adequacy Metrics LOLE: loss of load expectation (%) –Number of hours with curtailment divided by the total number of hours simulated –Can be more intuitive, i.e. 99.5% reliable –Does not address magnitude EUE: expected unserved energy (MW-hr) –Average amount of unserved energy per year –Lacks specific information about severe events

24. October 16, 2009Resource Adequacy Technical Committee 24 Work Plan PSRI review complete by early 2010 Benchmark GENESYS by early 2010 Tech Committee propose new metric and threshold by April of 2010 Use new metric to assess 3 and 5 year adequacy by June 2010