Generation Adequacy Task Force Update to WMS November 18, 2009

GATF has met 3 times: Sept. 22, Oct. 13, and Nov. 3, 2009 Next meeting set for December 1 st. GATF Charter and Goals Developed and included in last month’s update: –Highlights of goals: Review all the findings and recommendations from the previous GATF reports. Thorough review of CDR Recommendation for EILS Recommendations for new technologies (solar, storage, etc.) Recommendation for new LOLP (target reserve margin) study (GATF input into assumptions, data sources, results, etc.). Complete a draft report by the December 2009 WMS meeting that provides ERCOT planning with recommendations on all the assumptions to use in the target reserve (LOLP) study and subsequent reserve margin calculations. Complete a final report for consideration and vote at the January 2010 TAC meeting Wind Historical Data Provided by Luminant: Meeting Updates

CDR: Thorough review will occur on December 3 rd. –Is 5 year horizon adequate? –Does it need high and low forecasts? –Flow diagram of processes –Why is county data needed? EILS methodology is still under development LOLP Study (Target Reserve Margin) Discussion –Inputs and assumptions were reviewed at Nov. 3 rd meeting. What will be the source of information for generation forced outage rate assumptions? What years will be studied? Will transmission topology be modeled? If so, to what level of detail? What assumptions will be used for scheduled maintenance of resources? What type of generation technology should be utilized when estimating the effective load carrying capability (ELCC) of wind resources? What resource technology types should be added to the study when determining reserve margins? What modifications, if any, should be made to the model’s input assumptions regarding wind resources? Should wind be modeled with different ELCCs based on their geographic location (west, coastal, etc.)? What assumptions should be made for other renewable technologies (solar, biomass, etc.)? What is the source of information for generation forced outage rate assumptions? Synopsis of Discussions and Issues

Luminant provided an overview of wind historical data –Indicated current 8.7% level in CDR may be too low. –ERCOT staff believes their studies will also indicate an increase in the ELCC for wind, primarily due to the increased wind generator quantities and more geographic diversity among wind farms today Synopsis of Discussions and Issues

Wind Data Supplied by Luminant

Impact of Revised ELCC on Reserve Margins Supplied by Luminant

Questions or Comments?