1. Early Delivery System Testing Planning – Involving Market Participants TPTF May 22, 2007 http://nodal.ercot.com 1

2. Objectives for today’s presentation • Discuss EDS 3 Plan document TPTF comments • Get acceptance of the EDS Timeline plan as a baseline • Get agreement on additional MP involvement and the concept of the MP Handbook • Share the focus and content for the first EDS 3 MP Workshop on 24th May http://nodal.ercot.com 2

3. Market Trials Approach No Longer Valid • This document was presented to TPTF twice in November 2006 • Not approved due to insufficient detail • Document contained approaches and dates no longer valid • This document has been archived on the Nodal site, please disregard and do not use as a reference http://nodal.ercot.com 3

4. EDS 3 Plan - Response Approach & Main Comment Categories Comments responded to were included in the document and the necessary responses included in the spreadsheet http://nodal.ercot.com 4

5. EDS 3 Plan - Summary of pending issues and plan of action All comments in the pending category related to the requirement for further detail and were classified as pending. These areas will be explored further during ongoing planning forums. http://nodal.ercot.com 5

6. Planning & MP Involvement Approach http://nodal.ercot.com 6

7. Ongoing EDS Planning Process http://nodal.ercot.com 7

8. EDS Testing Artifacts EDS Approach Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec EDS EDS 3 Upload Offers Reg LMP Data Validation 6 month LMP Posting Rel 5 Rel 6 LFC COMs Testing LFC Testing Rel 7 CRR Data Validation Trial Ops of CRR EDS EDS 4 Rel 8 Settlements Statements Test Settlements Full Nodal Functionality 24*7 Operation Rel 9 168 Hr Test Upload Bids Outages DAM, RUC, SASM Go-Live Activities RTM Go-Live DAM Go-Live MP Interface Spec EDS 3 Plan EDS 4 Plan TPTF Information TPTF Approval SCED Handbook LFC Handbook CRR Handbook DAM Handbook S&B Handbook 168 Hour Test Handbook Go-Live Handbook Legend EDS 3 Major milestones EDS 4 EDS Preparation Milestones EDS Testing Status Reporting ERCOT & MP Readiness Reporting http://nodal.ercot.com 8

9. The Nodal timeline contains early EDS phases to ensure ERCOT & MP readiness … Early Start http://nodal.ercot.com 9

10. Participation in the EDS 3 Testing Phases (Section 1.4 – EDS 3 Plan) * Starting in October Market Participant involvement is critical to begin producing “Reasonable” LMPs. During this period the Market Participants should have a partial EDS system in place to support the activities and functionality being demonstrated. The EDS team will provide workshops during this time to support Market Participants. Required Market Participants that are not able to participate will have to still perform these activities by requesting a ‘make-up’ workshop prior to involvement in later EDS activities. There will be limited opportunities for support due to focus on other EDS functionality. ** The EDS team recommends that all QSEs with resources schedule some time to get familiar with the SCED user interface even if they are planning on utilizing APIs in production. This will help ensure that Market Participants have a second method for accessing the EDS systems if their APIs are not functioning correctly. http://nodal.ercot.com 10

11. Texas NodalSCED Workshop – 24th May 2007SME Support Requirement Scenario10 May 2007 http://nodal.ercot.com 11

12. Workshop Objective and Future Plans • Share the draft Market Participant Handbook for SCED testing • Answer any planning and testing questions from MPs present • Target MPs at the workshop will be QSEs with resources • The workshop will take place at MET Center and WebEx facilities will be available throughout • The Market Notice and a reminder has already been sent (see slide #4) • Answers to the questions provided at the workshop will be included in the MP Handbook to be used by the MPs during testing • This workshop will be the first in the series of either monthly meetings or WebEx’s to prepare ERCOT and the MPs for Market Trials which begin in July 2007 – Frequency? http://nodal.ercot.com 12

13. *******TEXAS NODAL MARKET NOTICE******* • NOTICE DATE: May 8, 2007 • NOTICE TYPE: General – EDS 3 Planning Workshop • SHORT DESCRIPTION: ERCOT will host the first in a series of EDS 3 Planning Workshops on Thursday, May 24, 2007. • INTENDED AUDIENCE: NTPM and EDS 3 Technical Contacts • DAY AFFECTED: May 24, 2007 • LONG DESCRIPTION: To ensure both ERCOT and Market Participants can maximize the benefits of the EDS, ERCOT will be hosting EDS Planning Workshops as well as ongoing conference calls to complete the details required for EDS 3 execution. This test planning workshop will provide early details on submittal of resource data elements, test preparation, testing scenario review and development, testing calendars, and specific exit criteria for EDS 3. • The first EDS 3 Planning Workshop is scheduled on Thursday, May 24, 2007 from 9:00 a.m. until 4:00 p.m. This workshop is targeted to Nodal Transition Project Managers and EDS technical planning team members involved in Security Constrained Economic Dispatch (SCED) input and validation testing. The agenda for this workshop will be distributed with all workshop materials prior to the meeting date. • The agenda topics for the first EDS 3 Planning Workshop include: • EDS 3 Readiness Activities • Walkthrough EDS 3 SCED workshop materials, which will be distributed to participants prior to the workshop • Phase 1 – July through September Activities • Phase 2 – October through December Activities • Input data methodology • Participant feedback, comments, key issues • Technical Questions and Answers with Project Subject Matter Experts on the MMS and EIP • EDS 3 Entry & Exit Criteria Discussion – Per Phase • Open Question & Answer period • Discuss Ongoing Planning Forums • ACTION REQUIRED: Please RSVP by replying to this notice or sending an email to NodalMarketTransition@ercot.com. Please provide the Market Participant company you are representing as well as additional attendees and their email addresses. If you wish to designate an alternate in your place, please indicate so in your RSVP. • ADDITIONAL INFORMATION: The seminar will be held on Thursday, May 24, 2007 from 9:00 a.m. until 4:00 p.m. CDT at: • ERCOT Austin • 7620 Metro Center Drive • Room 206 • Austin, Texas 78744 • 512-225-7000 • A map and driving directions can be found at http://www.ercot.com/about/locations/map_austin.html. • To participate in the workshop using WebEx, follow the steps below: • 1. Go to https://ercot.webex.com/ercot/j.php?ED=1609438&UID=0 • 2. Enter your name and email address. • 3. Enter the meeting password: EDS3123!! • 4. Click "Join". • 5. You will be provided a dial-in telephone number upon joining the WebEx. • CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via e-mail at NodalMarketTransition@ercot.com. • If you are receiving e-mail from an ERCOT distribution list that you no longer wish to receive, please follow this link in order to unsubscribe from this list. • (http://lists.ercot.com/cgi-bin/majordomo?module=) http://nodal.ercot.com 13

14. Typical Questions (Not all MMS or SCED related) • What are ERCOT’s expectations of hardware on the MP side? Does ERCOT expect MP’s to have “go-live” hardware installations in place by July? • Does the previously published SLA apply to the “Early” EDS testing of July – September? • When will MP’s receive the testing scripts referenced in 2.2.1? Also, in the same section, there is a reference to a Communication Process/Tool. Is this in place and documented or is it referring to the SLA? • On the EDS 3 Staffing Organizational Chart (7.2), can you please include names where possible? This is shown on the EDS 1 Chart and we have found it very helpful. • Please elaborate on “Mock Settlement Statements” and what this means (Section 5). We need more detail on what “Mock Settlement” looks like and what software we need to have in place to be ready. More importantly, our vendors need to have more clarity. • When will the “Error Notification API” be delivered (2.2)? This API is a crucial deliverable for effective testing and debugging of software problems. • Note: how do MPs see the data which have been accepted by ERCOT? • Execution of SCED utilizing Real-Time ICCP data – October 07 - does this step include the ability to create proxy curves? • SCED MIS Reporting – November 07 – can MPs see their Resource HASLs, LASLs, SURAMPs, SDRAMPs, HDLs, LDLs via MIS? • QSE Interactions with Interface Testing – is this required to access MIS and/or to use Machine-to-Machine interface? • Each Resource’s responses will be measured against the regulation signals - will LFC ability to calculate and issue Emergency Base Point be tested? • The QSE under test will be asked to submit resource level base points to match its schedule for the test hour. The base points provided should be at 5 min intervals - can QSEs send their resource Base Points to ERCOT via ICCP? • SCED (for base points) - which function calculates the proxy curves? Is it part of this package? http://nodal.ercot.com 14

15. Agenda - AM http://nodal.ercot.com 15

16. Agenda - PM http://nodal.ercot.com 16