1. Lead from the front Texas Nodal http://nodal.ercot.com 1 EDS 3 Release 5 Monday / Friday Market Updates March 07, 2008

2. Lead from the front Texas Nodal http://nodal.ercot.com 2 Agenda Antitrust Admonition Submissions Update –This Week’s Activities –Submissions Status Updates / Questions / Reminders External Interface Specification 1.09 Review LFC Update Q&A / Open Forum Roll Call

3. Lead from the front Texas Nodal http://nodal.ercot.com 3 Antitrust Admonition ANTITRUST 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.

4. Lead from the front Texas Nodal http://nodal.ercot.com 4 Submission Times for 03/10/08 Activities for Week of 03/10/08 –Submit the following during the 12:00 – 4:00pm submission window: COP TPO for trade date +2 Output Schedule (open to all resources) INC/DEC (DSR resources only) –Submit RT COP adjustments during business hours –Submit RT OS adjustments during business hours

5. Lead from the front Texas Nodal http://nodal.ercot.com 5 Submissions Status 2/29/20083/1/20083/2/20083/3/2008 93%85% 1182%73%976%71%990%83%9 COP TPO IDOOSCOP TPO IDOOSCOP TPO IDOOSCOP TPO IDOOS  Submissions still variable but improved  ERCOT continues to have system issues on a daily basis  This is being investigated by support  If ERCOT system issues are preventing dailies, contact ERCOT for assistance 3/4/20083/5/20083/6/20083/7/2008 98%93% 1096%91%1295%96%388% 2 COP TPO IDOOSCOP TPO IDOOSCOP TPO IDOOSCOP TPO IDOOS

6. Lead from the front Texas Nodal http://nodal.ercot.com 6 Updates / Questions / Reminders DST Issues: –For Sunday 3/9, in addition to the DST adjustment, omit the final hour of the day (e.g. do not include 23:00:00 – 00:00:00) –For submissions made prior to Sunday for Trade Dates after Sunday, omit the first hour of your submissions –For submissions made after Sunday 04:00:00, submit as normal (including the first interval of the trade date) with the new GMT offset -05:00:00 –DST Adjustment for Short Day: DST adjustment for short day Hour Ending 01:00:00 -06:00 Hour Ending 02:00:00 -06:00 Hour Ending 04:00:00 -05:00 (  note the GMT offset change) Etc…

7. Lead from the front Texas Nodal http://nodal.ercot.com 7 Updates / Questions / Reminders Reminder: Changes to Offer Curve Submissions –QSE’s can now start Adjusting for FIP/FOP Moving between 80/120 percent of cost –Week of 3/17, QSE’s will submit any desired curve based on assigned intervals Current FIP/FOP to be Used for Week of 3/10/08 –FIP = 9.505 –FOP = 21.65 EDS Environment Outages –3/03 – App Server Core Dump (root cause in review) –3/04 – Storage detached from app server –3/06 – App Server Core Dump (root cause in review) New Draft Version of Settlement Points Posted to EDS 4 Readiness Center –Sent out for comment 3/6/08 –EDS 4 Readiness Center: http://nodal.ercot.com/readiness/eds4/documents/index.html http://nodal.ercot.com/readiness/eds4/documents/index.html

8. Lead from the front Texas Nodal http://nodal.ercot.com 8 External Interface Specification 1.09 Review Outage Schedule – Section 7 –Corrected payload of “Get” AwardSet –Added the “Outage” to the payload of the “Create” OS Reply –Changed the verb from “Update” to “Change” in OutageSet to be consistent with the BidSets –5.3.12 Updated Outage notification structure –For Outage Query added for Request/ID to name value pair: OuatgeID or GroupID –Updated all Outage Scheduler XML Schema figures –Added description for Outage Types

9. Lead from the front Texas Nodal http://nodal.ercot.com 9 External Interface Specification 1.09 Review Short mRID –Corrected the Short mRID logic to include needed tokens for CRR, EB, EOO, PTP BID TypeType (XML tag) Short mRID Key String Ancillary Service OfferASOffer..ASO Ancillary Service TradeASTrade..AST Capacity Trade..CT Current Operating PlanCOP..COP CRR OfferCRR..CRR.Source.Sink DC Tie Schedule..DCT DAM Energy BidEnergyBid..EB.SP DAM Energy-Only OfferEnergyOnlyOffer..EOO.SP Energy Trade..ET Inc Dec Energy OfferIncDecOffer. Output Schedule..OS PTP Obligation BidPTPObligation..PTP.Source.Sink Self-Arranged ASSelfArrangedAS..SAA Self-ScheduleSelfSchedule..SS Three Part Supply OfferThreePartOffer..TPO

10. Lead from the front Texas Nodal http://nodal.ercot.com 10 External Interface Specification 1.09 Review Wind Forecasting –5.3.14 Updated the Wind Generation Notification Structure and section Tagged startTime and endTime as not used and deprecated (review Spec for effected Transactions Additionally several General Updates

11. Lead from the front Texas Nodal http://nodal.ercot.com 11 LFC Update QSE Organizations which tested this week: –Coral Power Issue encountered: –Data Point Mapping QSE Organization(s) Scheduled to test next week: –BTU Wednesday 9:00 AM CT Test Form revisions will be posted to the readiness center as necessary. Test Form submissions are to be submitted two business days before the test. All submissions should be sent to LFC@ercot.com.LFC@ercot.com Phase II Testing –Test Procedure & Test Forms posted on Nodal Readiness Center –Link: http://nodal.ercot.com/readiness/eds3/documents/index.htmlhttp://nodal.ercot.com/readiness/eds3/documents/index.html Phase III Testing LFC Phase III Pre Testing Workshop: –ERCOT will hold a market workshop at the ERCOT Austin Offices on Friday, March 14, 2008 from 9:00 am to 3:00 pm. –Workshop will provide A detailed overview of the pre-testing activities Required ICCP data submittals Schedule for EDS 3 Release 6.3 LFC pre-testing. This meeting will address test activities as called for in Section 5.2 of the EDS 3 - LFC Testing Market Participant Handbook v1.0, located at http://nodal.ercot.com/readiness/eds3/documents/index.html under the Release 6 – LFC section. http://nodal.ercot.com/readiness/eds3/documents/index.html The workshop will provide participants an opportunity to discuss EDS 3 Release 6.3 LFC testing activities and take part in a workshop with ERCOT personnel responsible for the test.

12. Lead from the front Texas Nodal http://nodal.ercot.com 12 Q&A Q&A / Open Forum