Lead from the front Texas Nodal 1 EDS 4 Outage Scheduler EDS Market Call April 25, 2008

Lead from the front Texas Nodal 2 ERCOT Anti-Trust 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.

Lead from the front Texas Nodal 3 Agenda Outage Scheduler –Release 9.2 update –External Web Services update –Q&A and Roll Call Appendix

Lead from the front Texas Nodal 4 Update on Outage Scheduler Recap from last week Testing with market participants being moved out 4 weeks. Testing to begin the week of 5/12 For convenience additional timeslots will be made available –Monday afternoons 1 – 3 PM –Late afternoons (Tues. thru Thur.) 4 – 6 PM –Friday mornings 9 – 11 AM Current Status Confidence on achieving revised start date of 5/12/2008 is higher Outage Scheduler, UI and associated External Web Services Internal testing in progress Outage Scheduler will be available in EDS environment for MPs week of 5/5, Market Notice will be sent out with this information Revised test package compliant to EIP V1.12 has been posted on the Nodal Readiness center Current known issues –Opportunity outage being redesigned, will be available for MP testing mid-May –UI and web services still be tested and tweaked WAN Update Targeting MP access to sandbox through WAN by week ending 5/2 ERCOT will schedule with MPs once issues access issues are resolved

Lead from the front Texas Nodal 5 Web Service Deliveries to Sand Box & EDS Final OS 5/1 in EIS 1.14 OS Notification EIS 1.14 document published ** 5/25/95/165/235/306/66/136/206/277/47/117/187/258/18/88/15 SNDBX OS Stable ** Skipping 1.13 as a version number

Lead from the front Texas Nodal 6 Market Participants not yet signed up for Outage Scheduler testing BRYAN TEXAS UTILITIES (TSP) FPL Energy Power Marketing FPL Energy Power Marketing (SQ3) FPLE PMI (SQ1) FPLE_WIND_FPL ENERGY POWER MARKETING INC.(SQ2) GREENVILLE ELECTRIC UTILITY SYSTEM (TSP) Medina Electric Corporation (TSP) MAGIC VALLEY ELECTRIC CORPORATION(TSP) Rayburn (TSP) STEC(QSE) Scurry County Wind (QSE) South Texas Electric Co Op(TSP) TEXAS MUNICIPAL POWER AGENCY (TSP) TEXAS NEW MEXICO POWER(TSP) Westar (QSE) City of College Station City of Denton

Lead from the front Texas Nodal 7 Q&A / Open Forum Roll-Call

Lead from the front Texas Nodal 8 -Release 9.2 Information -Connectivity information -Links to Key Documentation -Metrics -Data preparation APPENDICES

Lead from the front Texas Nodal 9 Outage Scheduler EDS 4.9.2: Objectives EDS Phase DescriptionPhase Objectives 9.2.1Forced Outage DetectionVerify the ability of the EMS to receive outage list from OS Verify the automation and timing of information from the OS to the EMS Verify the FOD capability of the EMS 9.2.2Connectivity / Submission test Verify MIS connectivity (if applicable) Verify EWS connectivity (if applicable) Verify MP’s ability to enter outages Verify ERCOT’s ability to approve single and group outages Verify QSE/TSP ability to receive updates on outage status 9.2.3Validation of PerformanceVerify OS ability to receive a specified quantity of data from multiple sources simultaneously via both the RUI and the EWS Verify OS data available for real-time reports 9.2.4Validation of Outage Evaluation in EDS Verify OS ability to send outage requests for the time period defined by the EMS user. Verify OS ability to receive outage status changes from the OE 9.2.5Validation of Outage Scheduler Interfaces Verify outage transfers from the OS into the DA TSA Verify outage transfers into RUC Verify outage transfers to all other uses of OS information 9.2.6Validation of Outage Postings in MIS Verify outage transfers from the OS into the MIS Validate MIS Secure Area access to Market Participants with the appropriate Digital Certificate Verify performance

Lead from the front Texas Nodal 10 Appendix - Outage Scheduler Testing: Basic Communications Test Prior to this test QSEs and TSPs using External Web Services will need to have their network and security teams make the following changes: –QSE’s / TSP’s Outage Scheduler system must be able to access: NOTE: this SSL URL is on port 80 –Market Participants must be able to receive / send transactions to/from the following IP ranges: / / /24

Lead from the front Texas Nodal 11 QSEs and TSPs using MIS (RUI) will need to have their network and security teams make the following changes: –Ports will be 80 and 443 –Market Participants must be able to receive / send transactions to/from the following IP ranges: / / /24 Appendix - Outage Scheduler Testing: Basic Communications Test

Lead from the front Texas Nodal 12 Key Documentation Key documents are available at

Lead from the front Texas Nodal 13 APPENDIX- DAM/RUC Tracking: Readiness Metrics MP8 - QSE Ability to Submit Transactions Via MIS –Expected completion date June 13 MP9 – QSE Ability to Submit Web Service Transactions –Expected completion date June 13 Execution –MP’s that have met readiness metric M8 or M9 by 6/13/08 are GREEN –MP’s that have attempted readiness metric M8 or M9 by 6/13/08 are AMBER –MP’s that have not yet attempted readiness metric M8 or M9 by 6/13/08 are RED In addition, TPTF approved MP20 to track MP ability to submit outages to the Nodal Outage Scheduler. The metric is yet to be approved by TAC ERCOT is calling all MPs that have not signed up for EDS4.9.2

Lead from the front Texas Nodal 14 Appendix- DAM/RUC Reference: QSE Data Preparation If QSEs or TSPs need their equipment list to verify xml submissions, please to ERCOT is unable to post the information online for all QSEs and TSPs because of the size of the file