1. January 21, 2008 TPTF Early Delivery Systems Status Daryl Cote

2. 2 2 TPTF1/21/2008 EDS Status Update 2007 2008 SCED R5.1SCED R5.3: RT ICCPSCED R5.4: LMP Post SepOctNovDecJan Feb SCED R5.2 ICCP Fail-over / P2P R3: SE / Telemetry Criteria (SE Tuning) R4: NOMCR / Network Model verification E1 R2 E2 R3 E2 R4 E3 R5 E3 R6 LFC R6.1: ACE E3 R7 CRR R7.1 E4 R9 R9 6-month LMP Posting SE Verification RT ICCP NOMCR Checkout Network Model Verification EDS 1 Exit Criteria % of MPs % of Points Comments MPs have completed PtP checkout and topology review for all submitted Nodal points (MP5) 95% (95%) 99% (99%)  37 of 38 MPs tested.  XTend remains to be tested, positive communications recently. ERCOT has completed local failover testing with each MP (MP6)97% (87%) n/a  37 of 38 tested.  XTend remains to be tested. ERCOT has completed Alarm Processing configuration and testingn/a  Alarm processing configuration and testing will be implemented with EMS 5. ERCOT has completed all PtP process documentation to support checkout for new construction / future changes to telemetry 100% (95%) n/a  Final process handoff and transition to Operations completed in December. Outstanding ICCP issues <= 3% per MP (MP5)100%n/a  Overall error rate ~1%. Quality Code Retesting (MP5)100%n/a  37 of 37 MPs regression tested with quality code fix. Reporting Legend: % in parentheses are from the 11/05 TPTF update EDS 1 Approach will be submitted to TPTF for completion approval on Feb 8

3. 3 3 TPTF1/21/2008 Alarm Processing Approach – Expected Delivery Schedule Alarms Highlighted in Yellow have been configured and Tested by Market Participants: – Reliant – CenterPoint – Luminant The processing of the remaining Alarms require code upgrades which will be included in the EMS 5 delivery. Target delivery for EMS 5 is May ‘08

4. 4 4 TPTF1/21/2008 Release 3 – State Estimator and Telemetry 2007 2008 SepOctNovDecJan Feb ICCP Fail-over / P2P R3: SE / Telemetry Criteria (SE Tuning) E1 R2 E2 R3 SE Verification EDS 2 Release 3 Exit Criteria % Complete Comments TSP/QSE data points reasonably conform to Telemetry and SE Performance criteria 70% ~1000MW delta in Generation data ~4000 TSP points need investigation ERCOT Operations have operating procedures in place to address performance issues 30% (30%) 8 of 27 procedures have been updated. The remaining will be completed when Release 3 processes are verified. Network Security Analysis functions are verified and ERCOT Operations have procedures in place to manage 76% (76%) Latest releases addressed some issues and a release in Late January should address the remaining issues. ERCOT SE is tuned and meets performance criteria43% (15%) Convergence and Tolerance – see slide 6 Unobservable – see slide 8 Load Modeling restructured, load adaptation and bus load forecast verified 75% (50%) Schedules loaded into EDS in early November. EDW reports correctly post to MIS and can be accessed40%SE Performance reports are completing FAT testing. Telemetry reports will be provided using a workaround until early 2008. EDW reports have been verified within ERCOT and by MPs 0%Telemetry and State Estimator standards in stakeholder process. Legend: % in parentheses are from the 11/05 TPTF update

5. 5 5 TPTF1/21/2008 SCED Inputs (Telemetry and ICCP to SCADA) 100% of requested data received by ERCOT. Verification of data in process: –Austin Energy, AEP, APX, Brazos, BP, BTU, Calpine, Constellation, Coral, CPS, Exelon, FPL, Garland, LCRA, NRG, OXY, Reliant, STEC, Suez, Tenaska, and Luminant –Does not include weather data This status reflects efforts by ERCOT to complete all ICCP and SCADA mapping. ERCOT is developing reports to isolate quality issues and will be contacting QSEs & TSPs directly to help resolve issues

6. 6 6 TPTF1/21/2008 Convergence Rate No Convergence due to System Outage

7. 7 7 TPTF1/21/2008 EDS 2 – State Estimator and Telemetry Criteria Telemetry CriteriaStatusComment Data Quality (MW/MVar Tolerance) At 100Moved it back to 100 after upgrade Telemetry Availability tbdNeed EDW Report Critically Important Telemetry tbdNeed EDS Report Availability for Critically Important Telemetry tbdNeed EDW Report Requests for Redundant Telemetry tbdNeed Critical Measurement functionality State Estimator CriteriaStatusComment SE Convergence Stable at 50MW variance when application is running (e.g. not down due to hardware or database loads) Transmission Element SE Accuracy tbdNeed EDW Report Critical Transmission Element SE Accuracy tbdNeed EDW Report Critical Bus Voltage Accuracy tbdNeed EDW Report SCADA Measurement Accuracy tbdNeed EDW Report Status of SE and Telemetry Criteria

8. 8 8 TPTF1/21/2008 Observability Status

9. 9 9 TPTF1/21/2008 Release 4 – NMMS / NOMCR 2007 2008 SepOctNovDecJan Feb R4: NOMCR / Network Model verification E2 R4 NOMCR Checkout Network Model Verification  Start of EDS 2 - R4 NOMCR has been moved to week of 3/17/2008  NMMS will be available in a “Sandbox” environment enabling market participants to become familiar with the system starting week later this week  Software defects with severity one have been experienced in FAT testing, which are causing delay for starting the EDS 2 Release 4 - NOMCR  NMMS/NOMCR overview training have been completed by the market participants  Citrix connections have been successfully installed and validated for 90% of the testing participants

10. 10 TPTF1/21/2008 Release 4 –NOMCR Schedule #TSP Network Model Management Training EDS Training 2 days @ ERCOT EDS Testing 5 days @TSP Site 1AEP/CPL10/29 to 11/1/20074/7 to 4/8/20084/9 to 4/15/2008 2AEN1/2 to 1/4/20084/16 to 4/17/20084/18 to 4/24/2008 3COD-City of Denton1/8 to 1/10/20085/7 to 5/8/20085/9 to 5/15/2008 4COG-City of Garland1/2 to 1/4/20084/16 to 4/17/20084/18 to 4/24/2008 5BEC1/2 to 1/4/20084/28 to 4/29/20084/30 to 5/6/2008 6CPS1/2 to 1/4/20084/16 to 4/17/20084/18 to 4/24/2008 7MVEC1/2 to 1/4/20084/28 to 4/29/20084/30 to 5/6/2008 8PUB1/8 to 1/10/20084/28 to 4/29/20084/30 to 5/6/2008 9TNMP1/2 to 1/4/20085/7 to 5/8/20085/9 to 5/15/2008 10STEC (1)1/2 to 1/4/20085/7 to 5/8/20085/9 to 5/15/2008 11ERCOT CRR TEAM1/8 to 1/10/20083/26 to 3/27/20083/28 to 4/3/2008 12ERCOT Planning Group1/8 to 1/10/20083/26 to 3/27/20083/28 to 4/3/2008 13BTU1/8 to 1/10/20085/19 to 5/20/20085/21 to 5/27/2008 14CSTX City of College Station1/8 to 1/10/20083/26 to 3/27/20083/28 to 4/3/2008 15GEUS-Greenville1/8 to 1/10/20083/17 to 3/18/20083/19 to 3/25/2008 16MEC1/2 to 1/4/20085/19 to 5/20/20085/21 to 5/27/2008 17CNP1/8 to 1/10/20083/17 to 3/18/20083/19 to 3/25/2008 18TXUED1/8 to 1/10/20085/19 to 5/20/20085/21 to 5/27/2008 19RCEC-Rayburn Country Electric1/8 to 1/10/20084/28 to 4/29/20084/30 to 5/6/2008 20TMPA1/2 to 1/4/20085/7 to 5/8/20085/9 to 5/15/2008 21STEC (2)1/8 to 1/10/20083/26 to 3/27/20083/28 to 4/3/2008 22LCRA1/2 to 1/4/20085/7 to 5/8/20085/9 to 5/15/2008

11. 11 TPTF1/21/2008 Release 5 - SCED 2007 2008 SCED R5.1SCED R5.3: RT ICCPSCED R5.4: LMP Post SepOctNovDecJan Feb SCED R5.2 ICCP Fail-over / P2P R3: SE / Telemetry Criteria (SE Tuning) R4: NOMCR / Network Model verification E1 R2 E2 R3 E2 R4 E3 R5 E3 R6 LFC R6.1: ACE E3 R7 CRR R7.1 E4 R9 R9 6-month LMP Posting SE Verification RT ICCP NOMCR Checkout Network Model Verification EDS 3 Release 5 Exit Criteria % Complete Comments QSEs w/ Resources able to submit COP & TPO for entire portfolio 100%Known issues with Output Schedules and Performance issues (root cause analysis done on performance issues and passed to teams) SCED Inputs verified: HRL, LRL, SURAMP, SDRAMP, HDL, LDL; GTBD, ICCP 40% (40%) Mobilizing team to monitor inputs much more rigorously over the next two- three weeks. SCED Outputs verified: QSE’s ability to receive Resource Base Points and LMPs via ICCP 35% (35%) Mobilizing team to monitor inputs much more rigorously over the next two- three weeks. Base Point and LMP calculation verified for Resources with Offer Curves or Output Schedules 0%Mobilizing team to monitor inputs much more rigorously over the next two- three weeks. Reports100% (50%) Reports related to SCED are available in draft form on MIS and nodal.ercot.com LMPs verified for Reasonability and posted to MIS for Market Participant review0% Expected completion by Feb 15 th Reporting Legend: % in parentheses are from the 10/22 TPTF update

12. 12 TPTF1/21/2008 Release 6 - LFC 2008 JanFebMarAprMay Jun E3 R6 R6.1: ACE & RLC EDS 3 Release 6.1 Exit Criteria % CompleteComments Test Time Scheduled100%Dates have been set with all QSEs with Resources. Schedule provided on next slide. First two QSEs had to be moved due to ERCOT upgraded taking longer than expected Completed Test Form Received back from MP9%2 of 22 submitted. Note the test form has been updated and reposted on 1/17/08. Forms due to ERCOT 2 business days before the scheduled test date. RLC Validation Completed0%Completed most of the testing effort on Tenaska. ERCOT working to resolve Responsive Reserve Deployment Flag and RLC logic issues Emergency Base-Point Validation Completed0% Legend: % in parentheses are from the 10/22 TPTF update R6.2: QSE TestingR6.3: TST Link for LFC Documents & Status: http://nodal.ercot.com/readiness/eds3/documents/index.htmlhttp://nodal.ercot.com/readiness/eds3/documents/index.html

13. 13 TPTF1/21/2008 Release 6.1 – LFC Testing Status & Schedule Testing for BP Energy and CPS was rescheduled due to ERCOT software update Testing for Tenaska was conducted Thursday January 17 th ; completed ~ 80% ERCOT Issues: –Responsive Reserve Deployment Flag –RLC logic Will proceed with tests scheduled for week of 1/21 –Regression test as needed

14. 14 TPTF1/21/2008 Release 7.1 - CRR EDS 3 Release 7.1 Exit Criteria % Complete Comments Logged-in and accessed the CRR application0% Downloaded one of the pre-auction market information0% Uploaded a bid/offer portfolio (in either XML or CSV)0% Edited a bid/offer within a portfolio (confirms web browser supports java applets) 0% Downloaded auction market results0% Created a sell/buy bilateral trade posting0% Accepted a sell bilateral trade posting0% Jan 08Feb 08Mar 08Apr 08May 08Dec 07 CRR–R7.0CRR–R7.1CRR–R7.2CRR–R7.3CRR–R7.4CRR–R7.5 (TBD) Jan 08Feb 08Mar 08Apr 08May 08Dec 07Jan 08Feb 08Mar 08Apr 08May 08Dec 07 CRR–R7.0CRR–R7.1CRR–R7.2CRR–R7.3CRR–R7.4CRR–R7.5 (TBD) ~80 participants on Kick-off WebEx on 1/18 – see ERCOT calendar for presentation Completing EDS environment build out putting pressure on Feb 4 th start

15. 15 TPTF1/21/2008 Release 7.1 - CRR participants Accent Energy AEPEP Air Liquide Large Industries U.S. LP American Electric Power ANP Funding I LLC Bank of America Brazos Electric Power Cooperative Inc. Brownsville Public Utilities Board BTU Calpine Corporation Cirro Energy Citi City of Austin dba Austin Energy City of Garland Commerce Energy, Inc. Coral Power CPS Energy DB Energy Trading LLC Desert Sky Wind Farm IPA Marketing Inc. Keystone Energy Partners LP Lower Colorado River Authority Luminant Energy Company LLC Morgan Stanley Capital Croup Inc. NRG Texas Power LLC Oxy Energy Rainbow Energy Marketing Corporation Reliant Energy Power Supply LLC Sempra Energy Solutions LLC South Texas Electric Cooperative, Inc. StarTex Power Strategic Energy Stream Energy Suez Energy Marketing NA Inc. Suez Energy Resources NW, Inc. Tenaska Power Service Co. Tex-La Electric Cooperative of Texas Inc. Trent Wind Farm West Texas Wind Energy Partners, LP Direct Energy, LP Eagle Energy Partners I LP Edison Mission Marketing & Trading Inc. EnergyCo Marketing & Trading LLC EPIC Merchant Energy TX LLC Exelon First Choice Power LP FPL Energy FPL Energy Pecos Wind I, LP FPL Energy Pecos Wind II, LP FPL Energy Upton Wind I, LP FPL Energy Upton Wind II, LP FPL Energy Upton Wind III, LP FPL Energy Upton Wind IV, LP GEUS Goldman Sachs Green Mountain Energy Company Indian Mesa Wind Farm, LP (LCRA) Indian Mesa Wind Farm, LP (TXU) Integrys Energy Services, Inc.

16. 16 TPTF1/21/2008 EDS 4 Release 9.1 2008 JanFebMarAprMay Jun E4 R9 R9.1: DAM/RUC Submission TestingR9.3:R9.4: DAM/ Adj Period, RT R9.3: Outage Scheduler EDS 4 Release 9.1 Exit Criteria% Complete Comments Intent to Participate Sent75% (0%) Sign-Up Testing Window Scheduled68% (0%) See next slide MP8 - QSE Ability to Submit Transactions Via MIS 0% (0%) MIS with ERCOT developed UI expected to be in EDS on 1/21 MP9 – QSE Ability to Submit Web Service Transactions 1% (0%) Reliant completed web services on 1/18 EPIC completed Connectivity Test MP16 - MP EDS-4 Trials Participation0% (0%)

17. 17 TPTF1/21/2008 EDS 4 Release 9.1 Alcoa Power Marketing Ambit Energy Ambridge Energy Aquila Bear Energy Brilliant Energy Cargill Power Markets Citadel Energy Products Clearview Electric Duke Energy Ohio Electric Now Glacial Energy J Aron Juice Energy Inc Just Energy Texas Kansas City Power and Light Keystone Energy Partners Lehman Brothers Commodity Services Liberty Power Corp LPT LLC Merrill Lynch Commodities Mirant Energy Trading Morgan Stanley MxEnergy Electric Inc QSE National Power Company Pegasus Alliance Corp Sitara Energy Spark Energy Texas Retail Energy Texas Star Energy Texpo Power Urban Energy Source Viasyn WCW International QSEs that have not signed up for a testing window for EDS4 (as of 2 pm 1/18/08) 3 Market Notices sent to date and Account Executives contacted by client services

18. 18 TPTF1/21/2008 EDS 4 Release 9.1 Signing up for an EDS 4 Release 9.1 Testing Window If you haven’t yet requested a testing window, please send the following to eds4@ercot.com: eds4@ercot.com Support Window date and AM or PM preference (provide 3 different slots) (testing began 1/15/08 and runs through March) ERCOT will make every effort to honor one or more of the preferred dates above; however, we may still need to coordinate around congested schedules. DUNS number of QSEs & sub-QSEs that will be tested within the support window Indication of desired testing method – MIS, machine-2-machine (Web Services), or both If using Web Services, confirm that QSE’s nodal production system is used for testing (whether in-house or third party): Yes/No If using Web Services, the listener URL where notifications will be sent Note: If your listener is unavailable at the time of sign up, the listener URL must be sent to the eds4@ercot.com email address 2 weeks prior to your scheduled testing window

19. 19 TPTF1/21/2008 EDS Deliverables R5.4 – SCED OS Handbook R9.2 COMs R8 DAM/RUC R9.3 Post for TPTF Comment 1/22Feb 8 Feb 15 Comment Close1/29Feb 15 Feb 26 TPTF VoteFeb 4/5Feb 21/22 Mar 3/4/5 Legend: indicates completion

20. 20 TPTF1/21/2008 Questions?