1Texas Nodal NATF Readiness Update Vikki Gates May 4, 2010

Nodal Training Curriculum Slide 2 CourseClassroomDaysAvailabilityWeb-Based* Nodal 101 1Scheduled  Load Serving Entity Scheduled  Basic Training Program 4Scheduled  Congestion Revenue Rights 1Scheduled  Economics of LMP 1Scheduled ERCOT 101 for Wind Generation 1January 2010  Generation 101 2Scheduled Generation 201 2Scheduled Transmission 101 2Scheduled Network Model Management 1January 2010  NOIE QSE Operations 1May 2010 Settlements 301 3June 2010 = Updated status

Nodal Training Curriculum Slide 3 CourseClassroomDaysAvailabilityWeb-Based* Nodal 101 1Scheduled  Load Serving Entity Scheduled  Basic Training Program 4Scheduled  Congestion Revenue Rights 1Scheduled  Economics of LMP 1Scheduled ERCOT 101 for Wind Generation 1January 2010  Generation 101 2Scheduled Generation 201 2Scheduled Transmission 101 2Scheduled Network Model Management 1January 2010  NOIE QSE Operations 1May 2010 Settlements 301 3June 2010 NOIE QSE Operations Begins: May 24th (Austin Energy) Will be scheduled at other NOIE venues (STEC in June) Will continue once a month through November Covers market issues that are of particular interest to NOIEs such as Dynamic Schedules, Output Schedules as well as PCRRs NOIE QSE Operations Begins: May 24th (Austin Energy) Will be scheduled at other NOIE venues (STEC in June) Will continue once a month through November Covers market issues that are of particular interest to NOIEs such as Dynamic Schedules, Output Schedules as well as PCRRs Settlements 301 Begins: June 9 th (Suez Energy - Houston) Will continue once a month through November A comprehensive look at Market Settlements (CRR Auctions, DAM, RUC and Real-Time) Expected to incorporate material from the Settlements Workshops (CRR, DAM, RUC/RTM) as well as Combined Cycle Workshops Settlements 301 Begins: June 9 th (Suez Energy - Houston) Will continue once a month through November A comprehensive look at Market Settlements (CRR Auctions, DAM, RUC and Real-Time) Expected to incorporate material from the Settlements Workshops (CRR, DAM, RUC/RTM) as well as Combined Cycle Workshops

Other Nodal Training Courses Slide 4 CourseAvailabilityClassroomWeb-Based Settlement Workshops Congestion Revenue Rights Day-Ahead Market Real-Time, including Reliability Unit Commitment May be repeated in the fall depending on Resource availability Verifiable Cost WorkshopsJune 3, 2010 MMS User InterfaceJune 30, 2010  Outage Scheduler User InterfaceMay 14, 2010  MIS User InterfaceJuly 30, 2010  = Updated status

Other Nodal Training Courses Slide 5 CourseAvailabilityClassroomWeb-Based Settlement Workshops Congestion Revenue Rights Day-Ahead Market Real-Time, including Reliability Unit Commitment May be repeated in the fall depending on Resource availability Verifiable Cost WorkshopsJune 3, 2010 MMS User InterfaceJune 30, 2010  Outage Scheduler User InterfaceMay 14, 2010  MIS User InterfaceJuly 30, 2010  = Updated status Verifiable Cost Workshop Repeated: June 3 (Suez Energy – Houston) Follows Combined Cycle Workshop on June 2 No further workshops scheduled after this session Verifiable Cost Workshop Repeated: June 3 (Suez Energy – Houston) Follows Combined Cycle Workshop on June 2 No further workshops scheduled after this session MMS User Interface Web-Based Training Only User Interface Training of the Market Management System Some of the content may be incorporated into future MRS presentations MMS User Interface Web-Based Training Only User Interface Training of the Market Management System Some of the content may be incorporated into future MRS presentations Outage Scheduler User Interface Web-Based Training available May 14th TSP Road Show Begins in June Follows Combined Cycle Workshop on June 2 No further workshops scheduled after this session Outage Scheduler User Interface Web-Based Training available May 14th TSP Road Show Begins in June Follows Combined Cycle Workshop on June 2 No further workshops scheduled after this session MIS User Interface Web-Based Training Only User Interface Training of the Market Information System Overview of MIS, Security levels, organization, demonstration of MIS, what the data represents and how to view and download from MIS MIS User Interface Web-Based Training Only User Interface Training of the Market Information System Overview of MIS, Security levels, organization, demonstration of MIS, what the data represents and how to view and download from MIS

Market Readiness Series Slide 6 Oct 2009Market Trials Kick-Off (Phase 2.1 and 2010 Roadmap) Jan 2010Real-Time and Day-Ahead Market Mar 2010Commercial Operations May 2010Cutover and Transition Activities (5/25) Aug Hour Test Five Market Readiness Series (MRS) are planned through Market Go-Live. Each MRS will support web conferencing for remote participation, and meeting materials will be posted. May 25 th MRS #4 Cutover Agenda: Background Scope of Cutover Project Assumptions for Cutover Approach Key Cutover Activities Cutover Timeline Market Participant Roles & Responsibilities Cutover Communication Next Steps

Next 60-days of Classes and Workshops Course Start DateLocation Credit Management WorkshopMay 3ERCOT Met Center (Austin) Economics of LMPMay 10Energy Plaza (Dallas) ERCOT Nodal 101May 10ERCOT Met Center (Austin) Congestion Revenue RightsMay 11ERCOT Met Center (Austin) Generation 101May 12TXU (Dallas) Transmission 101May 18CPS Energy (San Antonio) Network Model ManagementMay 20CPS Energy (San Antonio) Basic Training ProgramMay 24Energy Plaza (Dallas) NOIE QSE OperationsMay 24Austin Energy Town Lake Center (Austin) MRS #4 CutoverMay 25Hilton – Austin Airport (Austin) Generation 201May 26TXU (Dallas) Enrollment at:

Next 60-days of Classes and Workshops (continued) Course Start DateLocation Transmission 101June 1ERCOT Met Center (Austin) Combined Cycle WorkshopJune 2Suez Energy (Houston) Verifiable Cost WorkshopJune 3Suez Energy (Houston) Generation 101June 8LCRA (Austin) Market Settlements 301June 9Suez Energy (Houston) Generation 201June 17LCRA (Austin) Basic Training ProgramJune 21ERCOT Met Center (Austin) Load Serving Entity 201June 23Austin Energy Town Lake Center (Austin) ERCOT 101 for Wind GenerationJune 28ERCOT Met Center (Austin) Transmission 101June 29Energy Plaza (Dallas) Transmission 101July 13CenterPoint Energy (Houston) Enrollment at:

Procedure Publication Slide 9 Certain ERCOT desktop procedures will be published for Market Participants to review. General categories include: Functional Area ContentStatusLocation Day Ahead Market Operating procedures for the day ahead market Draft published 4/27 ess/markettrials/dam/index.ht ml WRUC WRUC ExecutionDraft published 4/27 ess/markettrials/dam/index.ht ml DRUC DRUC preprocesses, manual commitment/de-commitment, executing DRUC, resolving violated constraints Draft published 4/27 ess/markettrials/dam/index.ht ml HRUC HRUC ExecutionUnder reviewTBD CRR Subset of CRR Auction processes and postings Under reviewTBD Real-Time Desk Procedures Subset of real-time operating proceduresUnder reviewTBD