EDS 3 Release 5 and 6 Friday Market Updates Jan 23, 2009 http://nodal.ercot.com 1

Focused Input Testing Update Q&A / Open Forum (including API Subgroup) Agenda Antitrust Admonition Updates / Reminders Focused Input Testing Update Q&A / Open Forum (including API Subgroup) Roll Call 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. http://nodal.ercot.com 3

Updates / Reminders Unplanned Environment Outages 1/18 – 1/19 – Sandbox server certificate expired along with ERCOT public key. The public key only affected those that are verifying the ERCOT signature on synch responses and notifications. The updated public key is located at: http://nodal.ercot.com/readiness/sandbox/websvc/index.html 1/18 – Present – Market Manager Query Capability not functioning. Certificate used to validate EIS responses (public key) expired. This will be resolved EOB 1/22. Planned Outages 2/1 (Sunday Morning – 2pm) – Firewall maintenance on the EDS environment. All market submissions will fail during this period. UPDATE: EDS Program Schedule Update COMPLETE: Preliminary Nodal Integrated Schedule released COMPLETE: TAC initial review 12/4/08 COMPLETE: TPTF initial review 12/10/08 3:30-5:30pm (WebEx) Materials: http://www.ercot.com/calendar/2008/12/20081210-TPTFNOD COMPLETE: TPTF detailed discussion on 12/16 Materials: http://www.ercot.com/calendar/2008/12/20081215-TPTF COMPLETE: TPTF all day workshop on 1/07 Materials: http://www.ercot.com/calendar/2009/01/20090107-TPTF COMPLETE: TPTF session Monday 1/12 in the afternoon continuing Tuesday 1/13 all day Materials: http://www.ercot.com/calendar/2009/01/20090112-TPTF TPTF session 1/26 – continued discussions on the Nodal Integrated schedule Agenda to be posted at: http://www.ercot.com/calendar/2009/01/20090126-TPTF http://nodal.ercot.com 4

Focused Input Testing Update ALL TIMES ARE CENTRAL Duration Start date and time End date and time 27 hrs (3x9) January 27 - 8:00 am January 29 - 5:00 pm February 10 - 8:00 am February 12 - 5:00 pm February 24 - 8:00 am February 26 - 5:00 pm March 10 - 8:00 am March 12 - 5:00 pm March 24 - 8:00 am March 26 - 5:00 pm Next testing will take place 1/27 – 1/29 FIT II Assessment reports will be posted at: http://nodal.ercot.com/readiness/eds3/documents/index.html Reminder: remaining FIT windows will only review telemetry and state estimator convergence. SCED inputs will be removed from FIT until further notice. http://nodal.ercot.com 5

Q&A Q&A / Open Forum http://nodal.ercot.com 6