1. ERCOT Update on Day-Ahead Extract and other PUCT Posting changes DEWG Meeting 10/29/07 Matt Mereness

2. Agenda Summary of forthcoming changes from PUCT order Address questions circulated through DEWG Exploder after timing change made to Day-Ahead A/S Extract –Why was a change made? –Why was DEWG not notified? –Why was there no market notice? –Why does there exist the ability or mechanism for changes such as this to be made to Production extracts without notice? Next Steps

3. History Many wholesale market posting changes are being driven by two Commission Projects #31972 and #33490 –Among other changes, the PUCT projects increased offer caps and market transparency/reporting requirements (changes to Substantive Rule 25.505) –PUCT Project History: PUCT Project 31972 was initiated in 2005 Adopted 8/10/06, effective 10/1/06- –ERCOT developed an series of reports and special webpage to meet the requirements (http://www.ercot.com/gridinfo/sysplan/index.html ).http://www.ercot.com/gridinfo/sysplan/index.html –Many portions of the rule have staggered implementation timelines –ERCOT filed PRR697-Posting Requirements Change to codify the data posting changes in Protocols Approved by ERCOT Board on 4/18/07- (boxed language in protocols for lawsuit) –A lawsuit by Market Participants was filed and successful in suppressing changes to many QSE specific disclosures –PUCT project 33490 approved to modify disclosure timing, resulting in lawsuit being dismissed 9/19/07 –Commission staff communicated that 9/22/07 shall be effective date for the remaining disclosures

4. History Various new public reports were added to ERCOT systems for PUCT and Market Participants –System Adequacy Reports (Short, Medium, and Long-Term “PASA” reports) –Balancing Energy Reports- 48-hour disclosure of highest offer and QSE selected –A/S Offer Selected- 48-hour disclosure report –Balancing Energy and A/S Offers above Event Trigger- 7-day disclosure

5. Current Efforts Currently ERCOT is evaluating/implementing PUCT disclosure reports that were finalized in PUCT#33490 and effective for OpDay 9/22/07 –Created internal change requests to add and/or modify reports to come into compliance with ruling –SIR 11624 QSE-Specific BES Report: Portfolio offer curves for Balancing Energy for each settlement interval in entity-specific form for each area.QSE-Specific BES Report Change to extract required– Change from 180-day-MONTHLY disclosure to 60-day-DAILY disclosure –SIR 11625 QSE-Specific AS Report: Portfolio offer curves for each Ancillary Service for each settlement interval in entity-specific form for each area where available.QSE-Specific AS Report Change to extract required – Change from 180-day-MONTHLY disclosure to 60-day-DAILY disclosure

6. History ERCOT is evaluating/implementing PUCT disclosure reports (continued) –SIR 11626 Energy Schedules Report: Final energy schedules by entity by area for each settlement interval.Energy Schedules Report Change to extract required – Only change from 6 months to 90 days. –SIR 11627 AS Schedules Report: Final ancillary service schedules for each QSE for each area and service for each settlement interval.AS Schedules Report Change to extract required – Change from 6 months to 90 days. Change date range AND frequency to be DAILY

7. History ERCOT evaluating/implementing PUCT disclosure reports (continued) –SIR 11628 Resource Plans Report: Resource plans for each QSE for each area for each settlement interval.Resource Plans Report Change to extract required – Change from 6 months to 90 days. Change date range AND frequency to be DAILY –SIR 11629 Actual Resource Output Report: Actual output from each resource in entity-specific form for each settlement interval for each area. New report; daily posting, 90 days after Op Day –SIR 11630 Dispatch Instructions Report: All dispatch instructions from ERCOT for BES and AS in entity-specific form for each settlement interval for each area. New report; daily posting, 90 days after Op Day

8. History ERCOT evaluating/implementing PUCT disclosure reports (continued) –SIR 11631 Resources Committed Report: Names of resources in portfolio that were committed, name of submitting entity, name of controlling entity for each resource in portfolio by interval. New report; daily posting, 90 days after Op Day –SIR 11632 Dynamic Scheduling Report: Load and generation resource output for each zone, for each entity that dynamically schedules in entity-specific form for each settlement interval. New report; daily posting, 90 days after Op Day

9. Questions at hand Why was a change made? During the process of reconciling rule changes and existing postings, it was discovered two reports were posting earlier than allowed by protocols: - Day-Ahead AS Report - Aggregate AS Bidstack Report 12.4.4.2.3.2 Public ERCOT Posting ERCOT is required to provide market operation data to the public including but not limited to: … (13)Within two (2) days after the applicable Operating Day, but no earlier than the applicable Operating Day, aggregated data for each Settlement Interval (if applicable) and Congestion Zone (if applicable), for the following: (a) Quantities and prices of hourly bids for Balancing Energy and each type of capacity Ancillary Service, in the form of supply curves; (b) Self-arranged Ancillary Services, for each type of service, by hour When it was found the data was posting for the next Operating Day, rather than “no earlier than the applicable Operating Day”, ERCOT worked to correct the posting timeline. SIR initiated, worked with EIS team to develop, and with IO-CART to release. When asked as the Business Owner if a market notice was needed for the shift in timeline- the answer was “No”- which was a mistake on my part, and the reports were re-instated to original posting times and a Market Notice was sent advising the market of the posting change/correction.

10. Questions at hand -Why was DEWG not notified? -MktOps staff unaware of this requirement. Why was there no market notice? –Poor judgment by the Business Owner (self) in believing the shift in data timing did not warrant a notice. Why does there exist the ability or mechanism for changes such as this to be made to Production extracts without notice? –The Business Owner makes the call on the market notice- and if notice deemed required, works with Wholesale Client Services to draft the notice. -Lesson was learned- any extract changes require a market notice and shared/reinforced with others in Market Operations Support group

11. Next Steps -With release of Court Order, ERCOT is submitting PRR to effectuate Rule language into protocols (part of meeting materials) -ERCOT to release market notice advising market of new postings effective for 9/22/07 -ERCOT to release Market Notices of changes prior to 11/22/07 and 12/22/07 implemented changes -ERCOT interested in DEWG input guidance on least impact manner to change the two postings; -AS Bid Stacks (must move entire file/timeline back 2 days) -Day-Ahead AS Report (move extract back two days, or consider removing sensitive quantity data, or NULLs for quantity data) -ERCOT will distribute timeline for estimated implementation dates of new and changed reports to DEWG.

12. Next Steps -Questions? APPENDIX -Fields in Day Ahead AS Report –HOURENDING –MKTKTID –SERVICETYPE –REQUESTEDMW (Quantity required by ERCOT) –PROCURMENT (Quantity purchased) –CLEARINGPRICE –ASBIDMW (Quantity bid by market) Self-Arranged Amount is REQUESTEDMW-PROCUREMENT