Manual HDL/LDL Override Summary

1. Manual HDL/LDL Override Summary QMWG

2. Daily Summary Graph • For this analysis, we captured unique HDL/LDL overrides • An override is considered unique if that same Resource did not have an override within the last 10 minutes • There were 20 total unique overrides in July • As compared to 105 in June and 80 in May

3. Daily Summary Table

4. Reasons for Manual HDL/LDL Overrides • An override is considered unique if that same Resource did not have an override within the last 10 minutes • SPS Activation was the primary reason for the total number of HDL/LDL overrides during the month • 2 different Contingencies/ Constraints were given as the reason for an override

5. July 2011 Generation Resource Energy and Regulation Deployment Performance QMWG 8/8/2011

6. Month-to-Month NON-IRR GREDP – Energy Deployments Resources below 85% threshold - Resource 1 also failed in June and Resource 2 failed in May and June. Both Resources had similarGREDP scores and intervals scored each month.

7. Month-to-Month NON-IRR GREDP – Regulation Deployments • Resource below 85% threshold • Resource also failed in June with a GREDP of 72%, 28 MW deviation, and was • scored 3,640 intervals.

8. Month-to-Month IRR GREDP • Resources below 95% threshold • Best month since Nodal Go-Live. Effort to update HSL logic was a key contributor. • 23 resources failed for July. 19 of the 23 also failed in June. • 3 resources > 50 intervals • Weighted Average – 73% • Average Deviation – 12.5 MWs

9. IRR Total Intervals Scored – Month-to-Month

10. July GREDP by Fuel Type

11. July GREDP Scenario Analysis

12. Performance Monitoring Process QMWG 8/8/2011

13. Performance Monitoring Process • Monitor Performance – Protocols Section 8 • Investigate possible non-performance • Collaborative effort with Market Participants • Mid month calls • Review Performance, issues(s), improvements • Respond to requests for information/data • Informal requests for corrective action(s) • Cause Identified, Mitigation date(s) • Monitor for improved performance • If required: • Corrective Action Plan, Protocol 8.4 (1) • Possible Disqualification, Protocol 8.4 (2)

14. 8.4 ERCOT Response to Possible Non-Performance • ERCOT may require a Market Participant to develop and implement a corrective action plan to address its failure to meet performance criteria in this Section. The Market Participant must deliver a copy of this plan to ERCOT and must report to ERCOT periodically on the status of the implementation of the corrective action plan. • ERCOT may revoke any or all Ancillary Service qualifications of any Generation Resource or Load Resource for continued material non-performance in providing Ancillary Service capacity or energy.

15. Performance Monitoring Expectations, August 1st • GREDP Expectations, August 1st • Nodal in its eighth month of stabilization • ERCOT has worked with QSE’s to improve performance since go-live • Improvements have been implemented • Curtailment flag (5/18) • Dynamic ramp rates (7/25) • ERCOT required to identify non-performers to the Texas RE and PUC