1. Performance Monitoring- NPRR 256 QSE Managers Meeting August 10, 2010

2. Agenda • Discuss Goals of NPRR 256 and discussion on Performance Metrics • Identify Startup and Shutdown concerns and performance metrics • What is in NPRR 256 • What is not in NPRR 256 • Next Steps

3. Goals • Introduce NPRR 256 and some of the issues around performance metrics • Raise awareness of examples where performance metrics may not be reasonable or attainable • Eliminate GREDP from periods of testing and qualification, documented forced derates and startup failures • Clarify and align with other areas of the protocols qualification and testing responses • Discuss other issues and concerns from the market • Discuss next steps for performance metrics for Nodal go-live

4. Attainable Metrics- Startup/Shutdown • Performance metrics during Startup and Shutdown • Ramp rate constrained resources may require more than 1-hour time to reach registered LSL • Ramp rates during start-up and after breaker close may be variable and not capable of meeting base-points • Resources not released from start-up for dispatch when they reach 95% of LSL • Start-up of base load resources typically not released for dispatch until at or near maximum output • Shut-down when below 95% of LSL

5. Attainable Metrics- Startup/Shutdown • Ramping during Startup and Shutdown are not currently addressed in protocol Section 8, however, possible solutions include: • Set Resource Status to “ONTEST” and exempt Resources from GREDP when the unit status is “ONTEST” (language included in NPRR 256) • Set telemetered LSL to HSL until the unit is released for dispatch

6. Current NPRR 256 edits • Other issues addressed in the NPRR: • Exempting resources from GREDP and Base-point Deviation when under test and qualification for Ancillary Services • RRS qualification and telemetry update time changed from 15 seconds to 10 minutes • NS qualification changing the notification for the change in NS AS Schedule from 5 to 20 minutes • Strikes 8.1.1.4.1 (1) Regulation Service Energy Deployment Performance- Luminant believes this should align with zonal at 125% of each QSEs RU/RD Service requirement rather than total ERCOT requirement

7. Current NPRR 256 edits • Other issues addressed in the NPRR: • Excluding the 5-minute clock intervals during documented Forced Derate or Startup Loading Failure from GREDP • Clarification of the calculated GREDP and % pass/fail of 5-minute clock intervals during a declared EEA • Exempting resources from Base-point Deviation Charges during test and qualification periods as well as during resource status set to “ONTEST”

8. Issues not addressed in NPRR 256 • Luminant has provided a list of questions for clarification to ERCOT that has been discussed at QMWG • Many questions still are “In-progress” • ERCOT is developing an AS qualification and testing procedure based on Section 8 that will add details to the questions addressed in Luminant’s question matrix • AS Capacity monitoring questions regarding communications, time to resolve deficiencies, consideration of ramp rates

9. Issues not addressed in NPRR 256 • Deployment criteria requires additional clarification on TRE reported violations and integrating regulation signals into the GREDP calculation • Regulation deployment at 125% of requirement and the capabilities of meeting this deployment range which may exceed the resources ramp rate

10. Next Steps • Discussion and determination of potential issues not considered in NPRR 256 or the questions matrix • Provide additional comments to NPRR 256 from QMWG members • Discuss implementation at go-live for performance monitoring • Are there interim measures that can address the concerns identified if the system changes required from NPRR 256 cannot be implemented by December 1, 2010?

11. Questions