1. http://nodal.ercot.com 1 Nodal Stabilization Market Call December 21, 2010

2. http://nodal.ercot.com 2 Antitrust Admonition ANTITRUST ADMONITION ERCOT strictly prohibits Market Participants and their employees who are participating in ERCOT activities from using their participation in ERCOT activities as a forum for engaging in practices or communications that violate the antitrust laws. The ERCOT Board has approved guidelines for members of ERCOT Committees, Subcommittees and Working Groups to be reviewed and followed by each Market Participant attending ERCOT meetings. If you have not received a copy of these Guidelines, copies are available at the Client Relations desk. Please remember your ongoing obligation to comply with all applicable laws, including the antitrust laws. DISCLAIMER All presentations and materials submitted by Market Participants or any other Entity to ERCOT staff for this meeting are received and posted with the acknowledgement that the information will be considered public in accordance with the ERCOT Websites Content Management Operating Procedure.

3. http://nodal.ercot.com 3 General Updates / Reminders Reminder: Market Call tomorrow will be at 9:00 AM Update: Real Time Bill Determinants Missing in 12-1 to 12-3 RTM CODE Extracts ERCOT will provide this data to QSEs in a spreadsheet if it’s requested Send request for the data to your Wholesale Client Services Representative or markettrials@ercot.com FAQ: Expiration Date / Time clarification TPO / EOC submission contains an “Expiration Date/Time” field SCED retrieves EOC only once per hour, so any minute field specified is effectively ignored Examples: EOC submitted forExpiration TimeTime period SCED uses EOC 12/25 00:00-24:0012/26 00:0012/25 00:00-24:00 12/25 00:00-24:0012/25 23:0012/25 00:00-23:00 12/25 00:00-24:0012/25 22:3012/25 00:00-23:00 12/25 00:00-24:0012/25 22:0112/25 00:00-23:00

4. Credit: Invoices due Reminder – with the holiday there are a number of invoices due Monday, December 27 th (8 invoices) –Nodal – payable to market bank account DAM – OD Dec 16,17,18,19,20 (5 invoices due) RT – dated December 16 th (1 invoice due) –Zonal – payable to market bank account Invoice dated December 16 th (1 invoice) –ERO invoice (1 misc inv) – payable to ERCOT operating acct Please be sure your accounting/treasury folks are prepared to pay these invoices on Monday To ensure credit is applied correctly, please provide invoice numbers if paying more than one invoice with a wire transfer http://nodal.ercot.com 4

5. Credit: Payment reminders ERCOT is seeing improvement in timeliness of remittance but still see some payments coming in late –If payments are not in on time Payment breach or late payment for CP Short pay for the market –Notice of who has not paid Draw from collateral –Cash –LCs –Guarantees Payment may be made by Wire transfer – by 5:00 pm on due date ACH – by 5:00 pm two bank business days before the due date Note: JPMorgan Chase uses a different ABA number for wires (EFT) versus ACH. –if a CP is paying by wire – use ABA - 021000021 –if a CP is paying by ACH – use ABA – 111000614 http://nodal.ercot.com 5

6. Treasury A number of invoices are for small $s –Still must be paid on time Options –Prepay payments or initiate wires as “future dated” –Send several payments together Clearly identify all invoices being paid Do not “net” from outbound payments –Set up a small cash prepay account from which small $ payments can be deducted http://nodal.ercot.com 6

7. http://nodal.ercot.com 7 Questions?