Lead from the front Texas Nodal 1 EDS 4 Release 9.1 DAM/RUC/SASM Market Call January 25, 2008

Lead from the front Texas Nodal 2 Agenda DAM/RUC EDS –Antitrust Admonition –QSEs not signed up for testing –System Update –Master Schedule Update –Dashboard Update –Q&A and Roll Call Appendix –Connectivity and Digital Certificate information –Links to Key Documentation –Metrics

Lead from the front Texas Nodal 3 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 4 EDS 4 Release 9 Affordable Power Plan Alcoa Power Marketing Ambit Energy Ambridge Energy Aquila Bear Energy Brilliant Energy Cargill Power Markets Citadel Energy Products Clearview Electric ECONnergy 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 COB 1/24/08)

Lead from the front Texas Nodal 5 DAM/RUC Testing: Support Call Test Cases Primary QSESub-QSE Create / Query / Update / Cancel (if applicable) CRR OFFERAll Scenarios NOIE / PCRR Holders Only Create Only PTP ObligationAll ScenariosCreate Only Three Part Supply OfferAll Scenarios QSE w/ Resources Only Create Only Capacity TradeAll ScenariosCreate Only Energy TradeAll ScenariosCreate Only AS TradeAll ScenariosCreate Only DAM Energy-Only OfferAll ScenariosCreate Only DAM Energy BidAll ScenariosCreate Only AS Self ArrangementAll Scenarios QSE w/ Load Only Create Only AS OfferAll Scenarios QSE w/ Resources Only Create Only Self ScheduleAll ScenariosCreate Only DC Tie ScheduleAll ScenariosCreate Only

Lead from the front Texas Nodal 6 Update on EDS 4 Environment WebServices Interface –Available and being utilized by some QSEs with Resources –Two QSEs have completed API submissions ERCOT developed MMS User Interface –Migration of MMS User interface last night and configuring for testing –Rescheduling the impacted QSEs –Market Notice to be sent when available

Lead from the front Texas Nodal 7 Update on EDS 4 Environment Known Issues/Limitations –Issue with Credit Validation DAM Bids/Offers being rejected, workaround by submitting 2-days out –Issue with Load Resource submitting Self Arranged AS Fix expected February with next version of API web services –This is a correction to last week- was flagged for AS Offer –Query using short mRID is not available for: “PTP Obligation” / “DAM Energy Only Offer” / “Energy Bid” / “CRR Offer” / “AS Offer” –Negative test for Energy Bid not working (submission of curve <1MW) Will pass QSE without this test –DC Tie Schedule ERCOT to set up NERC tag data and communicate tag to be used in test –PtP Obligation Bids is REQUIRED (different from M2M/API spec) Set crrAccountHolderId = TSTQSE –Current list of issues to be posted by end-of-day today (1/25/08)

Lead from the front Texas Nodal 8 Update on EDS 4 Environment FAQ –Trades- Buyer and Seller need to be different Can use TSTQSE as counterparty –DC Tie Schedules- Use tie name as counterparty (DC_E, DC_N, DC_S) –BidId, OfferId OfferId or BidId on all transactions must be at least 2 characters –Expiration Date Standing offers not supported at this time (open ended expiration date) Energy Bid and Energy Only Offers expiration date is required field Set ExpirationTime = TradingDate –Combined Cycle Resource Name for offers must contain configuration TrainName_CC_1

Lead from the front Texas Nodal 9 DAM/RUC Tracking: Master Schedule for Next Week

Lead from the front Texas Nodal 10 DAM/RUC Tracking: Dashboard To view the most updated copy refer to the readiness center at: Under Weekly Status

Lead from the front Texas Nodal 11 DAM/RUC Reference: QSE Data Preparation Reminder to Download Settlement Points and QSE Short Name List (both files posted on Readiness- Both data sets are subject to change QSE Short Names used in transactions –Your QSE short name is needed as in XML Header –All QSE short names listed, but may change Can use ERCOT test QSE of “TSTQSE” to avoid populating and changing QSE list in your systems Settlement Point used as points of business in submission testing –Market Participants revisiting Resource Node SPs –Considering change from Low side to High side –Change would result in many SP name changes

Lead from the front Texas Nodal 12 DAM/RUC Reference: QSE Activity Summary Download and review the EDS 4 Test Package –Send sample XML to ERCOT no less than 2 weeks prior to Testing Window –Make Modifications (if any) to XMLs that ERCOT provides –Prepare final XML files for Support Call –Support calls are for troubleshooting submissions in real-time Prepare systems with Settlement Point data and QSE short name(s) Read and be familiar with key Documents (references in Appendix) Known issues will be posted to the Nodal Readiness Center under EDS 4: –File will be updated by COB 1/25 – Send all questions to

Lead from the front Texas Nodal 13 Q&A / Open Forum Roll-Call

Lead from the front Texas Nodal Connectivity and Digital Certificate information -Links to Key Documentation -Metrics APPENDICES

Lead from the front Texas Nodal 15 APPENDIX- DAM/RUC Testing: Basic Communications Test (“Ping” Test) BASIC COMMUICATION TEST Prior to this test QSE’s using External Web Services will need to have their network and security teams make the following changes: –QSE’s Market System must be able to access: NOTE: this SSL URL is on port 80 NOTE: this is changed from Release –QSE’s must be able to receive messages from –QSE’s must be able to send messages to EDS Environment: Sandbox Environment: QSE’s using MIS User Interface will need to have their network and security teams make the following changes: –Must be able to access: MIS URL: NOTE: MMS User Interface will have link from MIS NOTE: MIS/MMS UI are on port 443https://nodaleds.ercot.com/pps/tibco/mis/

Lead from the front Texas Nodal 16 APPENDIX- DAM/RUC Testing: Digital Certificates DIGITAL CERTIFICATES 1 digital certificate w/ a Generic Userid (NODALTEST) will be Generated for Each QSE and Sub-QSE –The MP’s USA does not need to take any action –This is the only certificate that will work in the EDS environment –This certificate will also work in the Nodal Sandbox environment –It will not work in production, MOTE, or any other ERCOT environment –The Digital Certificate will be sent to the MP USA Distribution will occur after the QSE signs up for a Testing Window and Just Prior to the Support Call –(for those requiring the basic communications test, it will be sent prior to that session) All valid ERCOT issued digital certificates will continue to work in the Nodal Sandbox

Lead from the front Texas Nodal 17 APPENDIX- DAM/RUC Reference: Relevant Documents EDS – DAM/RUC/SASM Test Package Settlement Point Listinghttp://nodal.ercot.com/readiness/eds4/documents/index.html QSE Short Name Listing To post by end-of-day Dashboard of Metrics and Schedule EDS Issue Submission Form sue_submission_form.xls EIP External Interface Specification s_specification_v1_06.zip Explanation of Market Submissions v0.25

Lead from the front Texas Nodal 18 APPENDIX- DAM/RUC Reference: Relevant Documents ERCOT Nodal Transition Plan Plan_ doc EDS 4 Approach v1.0http://nodal.ercot.com/readiness/eds4/documents/index.html EDS 4 - DAM/RUC/SASM Market Participant Handbook v1.0 Market Management System User Guide To be provided next week to be posted to Readiness Center

Lead from the front Texas Nodal 19 APPENDIX- DAM/RUC Tracking: Readiness Metrics READINESS METRICS: Sign-Up Testing Window Scheduled –QSE signs up by 1/4/2008 – Status is GREEN –QSE’s that have not signed up by 01/04/08 – Will turn Amber until signed up 03/15/08 – Will turn red MP8 - QSE Ability to Submit Transactions Via MIS –Expected completion date March 15 MP9 – QSE Ability to Submit Web Service Transactions –Expected completion date March 15 Execution –MP’s that have met readiness metric M8 or M9 by 3/15/08 are GREEN –MP’s that have attempted readiness metric M8 or M9 by 3/15/08 are AMBER –MP’s that have not yet attempted readiness metric M8 or M9 by 3/15/08 are RED MP16 - MP EDS-4 Trials Participation (phase 2) ERCOT is calling all QSEs that have not signed up for EDS4