1 Market Operations Presentation Board of Director’s Meeting August 16, 2005

2 Agenda Overall Activity Migration From Native AREPs Performance Measures (Quarter Only) Reliability Services Balancing Services Hub Summary Data Congestion Management Services Retail Activity Wholesale Activity Other Items

3 Overall Activity Transaction Type Switches1,935,034 Move - Ins6,834,283 Move Out3,945,931 CSA1,200,339 Drop to POLR302,496 Total14,218,083 Compared to Last Month 437,750 Retail Transactions Summary As of Thursday, June 30, 2005 since June 1, 2001

4 Residential Small Non-Residential Large Non-Residential Migration from Native AREP % of ESI IDs 16% 20% 60% 24% 29% 72% 30% 75% 73% % of Load * at at at * % of Peak Demand on

5 Q Performance Measures submitted to PUCT SWITCHES 814 Transactions - Enrollment and Meter Read Scheduling RequestRejectto TDSPScheduleto New CRto Old CRfrom Old CR 214,2407,514206,670208,537205,882168,944162,422 % in Protocoln/a99.0%99.9% 99.8%99.0%99.4% 867 Transactions - Historical Usage (H) and Initial (I) Meter Read Deliveries H to ERCOTH to CRI to ERCOTI to CR 196,529196,499160,666160,360 % in Protocol99.7%100.0%n/a98.9%

6 Q Performance Measures submitted to PUCT MIMO 814 Transactions - Enrollment and Meter Read Scheduling RequestRejectto TDSPScheduleto New CRto Old CRfrom Old CR 642,0529,333631,771624,062618,722322,631303,037 % in Protocoln/a90.3%93.4%99.9%96.8%99.1%99.8% 867 Transactions - Historical Usage (H) and Initial (I) Meter Read Deliveries H to ERCOTH to CRI to ERCOTI to CR 330,178330,174579,913578,919 % in Protocol98.7%100.0%n/a99.1% Protocol is 5 hours. Average timing outside of protocol was 12 hours, 12 minutes. Reject transaction calculation was found to be in error due to system handling of duplicate transactions submitted to ERCOT. A Service Investigation Request (SIR) has been filed to correct the error. Depending upon the amount of duplicates, the error may be as much as 6% to 8% lower than actual protocol compliance.

7 Reliability Services 06/30/0506/30/ Market Perspective: Approximate Retail Market (at $.10/kWh PTB) $13, ,471.52,973.32,670.9 Volume (GWh)138,331134,71529,73326,709 % Increase2.7%11.3% Natural Gas Price Index ($/MMBTU) % Increase14.0%16.1% RMR: RMR Capacity and Start Up RMR Energy BENA Credit Net RMR Other Capacity Services: Replacement Reserve0.0 Reg Up and Down Responsive (Spinning) Reserve Non-Spinning Reserve Black Start TOTAL RELIABILITY SERVICES$ YTD ($'s in millions) June ($'s in millions)

8 Balancing Services 06/30/0506/30/ Market Perspective: Approximate Retail Market (at $.10/kWh PTB) $13, ,471.52,973.32,670.9 Volume (GWh)138,331134,71529,73326,709 % Increase2.7%11.3% Natural Gas Price Index ($/MMBTU) % Increase14.0%16.1% Balancing Energy: Balancing Energy - Up$ % Increase 67.1%151.3% Up (GWh)5,146.03,911.51, % Increase 31.6%81.6% % of Market 3.7%2.9%5.1%3.1% Balancing Energy - Down-$ % Increase -30.7%-50.2% Down (GWh)-2, , % Increase -25.6%-51.4% % of Market1.8%2.5%1.4%3.1% YTD ($'s in millions) June ($'s in millions)

9 Hub Summary Data ERCOT Hubs TotalBalancing Average PriceVolumeUp VolumeDown Volume HUB($/MWH)(GWh) South$ North$ Houston$ West$ ERCOT Hub Average$73.431,919.31, ERCOT Bus Average$74.461,919.31, June Weighted

10 Congestion Management Services

11 Other Items Added RepsAdded QSEs Bridgepoint Power & Light, LLC Ideal Energy, Inc.