1. http://nodal.ercot.com 1 TSP Nodal Engagement Market Participant Call ERCOT September 15, 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. Full System Market and Reliability Test Update General Reminders / Updates Outage Scheduling Issues NDSWG Update – no update this week SSWG update – no update this week Issues List Update – TSP list received by ERCOT Agenda http://nodal.ercot.com 3

4. Market Trials 2010 Roadmap http://nodal.ercot.com 4

5. http://nodal.ercot.com 5 Full System Market and Reliability Testing Update

6. http://nodal.ercot.com 6 Full System Market and Realibility Update –48-Hour Test Test completed at 2pm 9/14/2010. No Major issues that do not have a work-around or process to address them CPS1 scores ranged from 103 to 193 CPS1 average for duration of test: 156 Full test summary will be presented to NATF on Friday 9/17/2010 details: http://www.ercot.com/calendar/2010/09/20100917-NATFhttp://www.ercot.com/calendar/2010/09/20100917-NATF –New: Next Full System Test 36 hours in duration To occur on 9/28/2010 and complete on 9/30/2010 Specific times will be communicated in the Friday Market Call preceding the test

7. http://nodal.ercot.com 7 General Reminders

8. http://nodal.ercot.com 8 General Reminders Reminder: Outage Scheduler Synchronization 09/17/2010: Deadline for validating / synchronizing outages effective for Dec 1, 2010 and beyond. When complete, send an email to markettrials@ercot.com.markettrials@ercot.com

9. http://nodal.ercot.com 9 Outage Scheduling Issues Update

10. http://nodal.ercot.com 10 Environment Report: Known Issues Known issues posted to the readiness center at: http://nodal.ercot.com/readiness/markettrials/os/index.html http://nodal.ercot.com/readiness/markettrials/os/index.html Newly Closed Issues (verbal update) StatusIssueDescription Closed MP reported the OS UI summary page is painting twice on the same screen Closed MP reported they are unable to enter an Actual End in outage

11. ERCOT TAC Meeting - ROS Report 03/04/2010 Ken Donohoo 11 Nodal Model Effort Activity Operations Model (NMMS) CRR Model Topology Processor (Software) Long Term Planning Model NDSWG Support SSWG Support SSWG Support SSWG & ERCOT Development

12. ERCOT TAC Meeting - ROS Report 03/04/2010 Ken Donohoo 12 Nodal Model Effort Activity Operations Model (NMMS) CRR Model Topology Processor (Software) Long Term Planning Model NDSWG Support SSWG Support SSWG Support SSWG & ERCOT Development