Demand Side Working Group April 23, 2010

1. Demand Side Working GroupApril 23, 2010 Mary Anne BrelinskyEDF Trading North America

2. Antitrust Admonition

3. Demand Side Working Group Agenda

4. 2010 DSWG Goals

5. Suspension of Dynamic Scheduling During EEA

6. LaaR Zonal Market versus Nodal Market

7. LaaR Zonal Market versus Nodal Market (cont.) • POTENTIAL AGENDA ITEMS FOR THE SUBGROUP: • Produce recommendation to DSWG on whether to sponsor PRR and NPRR, or NPRR only. • Consider implications of proration on resource-specific RRS offers. • Add unannounced testing provisions for Load Resources. • Provide more detailed definition of a performance failure. • Determine appropriate penalties for LR performance failures. • Determine appropriate penalties for QSE performance failures.

8. Expected Load Resource Scheduling A Load Resource is currently consuming 22 MWs and has a RRS schedule of 20 MWs. The Load Resource telemeters the following: Current Load = 22 MW RRS Schedule = 20 MW LPC = 0 MW LPC Limit = 0 MW ERCOT calculated LASL = 20 MW (LPC + RRS Schedule) Net Dependable Capability = 22 MW (Current Load – LPC) Load Resource Limit Calculator As depicted in Section 6.5.7.2 Of the Nodal Protocols HSL = MPC Increasing Consumption Regulation Down HASL HASL Normal Load Fluctuations Current Load Telemetry 22 MW Current Load Telemetry 20 MW LASL LASL Decreasing Consumption Decreasing Consumption Regulation Up Responsive Reserve Non Spinning Reserve 20 MW RRS Schedule 0 MW LSL = LPC = 0 LSL = LPC = LPC Limit 5 – 30 Minutes 5 – 30 Minutes

9. Expected Load Resource Event What happens during a deployment? A Load Resource is currently consuming 22 MWs and has a RRS schedule of 20 MWs. The Load Resource telemeters the following: Current Load = 22 MW RRS Schedule = 20 MW LPC = 0 MW LPC Limit = 0 MW ERCOT calculated LASL = 20 MW (LPC + RRS Schedule) Net Dependable Capability = 22 MW (Current Load – LPC) Load Resource sheds 22 MWs in less than 10 mins. 8.1.1.4.2 (d) During periods when the Load level of a Load Resource (excluding Controllable Load Resources) has been affected by a Dispatch Instruction from ERCOT, the performance of a Load Resource in response to a Dispatch Instruction must be determined by subtracting the Load Resource’s actual Load response from its Baseline. “Baseline” capacity is calculated by measuring the average of the real power consumption for five minutes before the Dispatch Instruction if the Load level of a Load Resource had not been affected by a Dispatch Instruction from ERCOT. The actual Load response is the average of the real power consumption data being telemetered to ERCOT during the Settlement Interval indicated in the Dispatch Instruction. The load would pass the event. HASL HASL 22 MW 22 MW Current Load Telemetry Current Load Telemetry 20 MW 20 MW LASL LASL Decreasing Consumption 20 MW 20 MW RRS Schedule RRS Schedule 0 MW 0 MW LSL = LPC = LPC Limit LSL = LPC = LPC Limit Minutes 0 10 Minutes

10. Load Resource Failure and Remedy What happens when a Load Resource fails to perform during a deployment? A Load Resource is currently consuming 22 MWs and has a RRS schedule of 13 MWs. The Load Resource telemeters the following: Current Load = 22 MW RRS Schedule = 13 MW LPC = 7 MW LPC Limit = 7 MW ERCOT calculated LASL = 20 MW (LPC + RRS Schedule) Net Dependable Capability = 15 MW (Expected Power Consumption – LPC Limit) Load Resource sheds 15 MWs in 10 minutes, 7 MWs shy of the LPC of 0 MWs. ERCOT Raises the LPC Limit by 7 MWs. HASL HASL 22 MW 22 MW Current Load Telemetry Current Load Telemetry 20 MW 20 MW LASL LASL 20 MW 13 MW RRS Schedule RRS Schedule Load is at 7 MW LSL = LPC = LPC Limit 7 MW 0 MW LSL = LPC = LPC Limit 0 10 Minutes 0 10 Minutes

11. Next Meeting and Schedule for 2010 • DSWG Scheduled Meetings and Meeting Details: • May 07, 2010 • June 04, 2010 • July 16, 2010 • August 13, 2010 • September 10, 2010 • October 08, 2010 • November 05, 2010 • December 03, 2010