1. Lead from the front Texas Nodal http://nodal.ercot.com 1 EDS Market Call Bi-Weekly Update Aug 21, 2009

2. Lead from the front Texas Nodal http://nodal.ercot.com 2 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. DISCLAIMER All presentations and materials submitted by Market Participants or any other Entity to ERCOT staff for this meeting are received and posted with the acknowledgement that the information will be considered public in accordance with the ERCOT Websites Content Management Operating Procedure.

3. Lead from the front Texas Nodal http://nodal.ercot.com 3 Agenda Anti-trust Admonition Day-to-day operations summary –Planned and Unplanned ERCOT outages of Sandbox –Sandbox Update Standing reports and updates –General Reminders / Updates –SEM go-live update –Focused Input Testing Question and Answers/General Discussion Deep Dive Topic (different topics each meeting as needed) - No Deep Dive this Week ERCOT asks that Market Participants log into the WebEx session using their company name and then their name. This will allow ERCOT to take roll-call offline

4. Lead from the front Texas Nodal http://nodal.ercot.com 4 Day-to-day operations summary: Planned / Unplanned Outages of EDS Planned Outages –8/18/09 11am – 1pm. Maintenance release. The following issues were resolved in this release: Not all bid submittal responses are compliant with the published XSD Trading date was erroneously required for ‘gets’ (additionally the EIS 1.19 will be corrected) Asynchronous responses to submitted transactions had values in the verb and noun that were inconsistent with the back end systems. The value of has been changed to “created”. The value of has been changed to “bidset”. (Note that previous values were “reply” and “notification” respectively). Usage of the short mRID was not functioning The last token was missing from the mRID in IncDecOffer asynchronous responses Synchronous responses to submitted transactions erroneously included the payload of the submitted transaction. Synchronous responses will now only include the mRID Get SASMIDList was not functioning Unplanned Outages –No unplanned outages to report

5. Lead from the front Texas Nodal Day-to-day Operations Summary: Sandbox Sandbox Current Usage: –Currently 3 QSE’s are using the Nodal Sandbox –As a reminder, the Sandbox currently has the EIS 1.19 –For those who wish to start using this environment, send an email to eds3@ercot.com for details on configurationseds3@ercot.com Reminder: any ERCOT digital certificate may be used to access the sandbox environment –Refer to the first slide in the appendix for information previously discussed on the “retirement” of the ERCOT issued NODALTEST certificates.

6. Lead from the front Texas Nodal Nodal Production – ERCOT Test Certificates ERCOT is requesting volunteers Market Participants to provide test certificates that will enable ERCOT’s ability to: –Support Market Participants during Trials activities by reproducing reported issues –Executing extensive regression testing following each software release to the Nodal Production environment Background: –Previously ERCOT used NODALTEST certificates to access the environment –This was possible as we were not yet integrated with MPIM and ERCOT was acting as each MP’s USA –Going forward with the October Release of the Nodal Production environment, MPIM will be integrated and MP’s USA’s will be the only users permitted to create certificates for that company What ERCOT Needs: –Sept 1, 2009, ERCOT will release all nodal roles to MPIM –ERCOT is asking for volunteer MP’s to generate a certificate for their company containing only these Nodal roles for a user called NODALTEST1 Note that we have placed a 1 on the user to avoid conflicts with the previously used NODALTEST user. –Once created, email the NODALTEST1 certificate to smiddleton@ercot.com Note that Scott Middleton will serve as the central point of control for these certificatessmiddleton@ercot.com –Once we have completed the 168 hour test, MP USA’s may revoke this certificate (ERCOT will also destroy it) –ERCOT would like a core set of certificates in place no later than October 1, 2009

7. Lead from the front Texas Nodal http://nodal.ercot.com 7 SEM Go-Live Update What is ERCOT doing this week? –Continued Stress test of SEM Go-Live Production system –August 18, 2009, the ERCOT Technical Advisory Committee (TAC) and ERCOT Board of Directors (Board) approved the Market Readiness Criteria for SEM Go-Live on August 31, 2009. –Market notice sent out on August 18, 2009 confirming Go-Live Reminder: Market Notice sent out to USAs for MPIM Roles for NMMS –Role available to assign NMMS Remote Users –ERCOT will details released to USAs on how to assign the roles for SEM Go-Live –Note that all users will receive new accounts/user names

8. Lead from the front Texas Nodal 10/19/2015 http://nodal.ercot.com 8 This FIT Update includes the following discussion items:  Near-term FIT Windows  FIT III Week 13 Results  Convergence Trends (Running Results Summary for FIT II & FIT III)  Upcoming Nodal Telemetry Outreach  Upcoming Changes to FIT  Upcoming Key Dates Standing reports and updates: Focused Input Testing (FIT) Update

9. Lead from the front Texas Nodal http://nodal.ercot.com 9 FIT Update: Near-term FIT Windows Next FIT testing will take place 8/25 – 8/27 (per Aug 20 Market Notice) Reminder: remaining FIT windows will only review telemetry and State Estimator convergence. The SCED inputs will be removed from FIT until further notice. ALL TIMES ARE CENTRAL DurationStart date and timeEnd date and time 27 hrs (3x9) Aug 25 – 8:00 amAug 27 – 5:00 pm 27 hrs (3x9) Sept 8 – 8:00 amSept 10 – 5:00 pm 27 hrs (3x9) Sept 22 – 8:00 amSept 24 – 5:00 pm

10. Lead from the front Texas Nodal Key Numbers and Issues:  96% Test Average Convergence; 92% or higher for 22 of 27 Test Hours; 100% for 19 of 27 Test Hours  The majority of issues that arose during the test were attributable to zonal-nodal mismatches as well as unit telemetry missing in nodal.  On Day One, convergence dipped to 69% during Hour Ending (HE) 1500 owing telemetry missing from two ICCP links that dropped during MP site-to-site failover.  On Day Two, convergence started at 69% (HE 0900) as manual replacements were made to address telemetry issues that were accumulated during non-Business Hours immediately prior to testing. A nodal database load was performed during HE 1500. http://nodal.ercot.com 10 FIT Update: State Estimator - FIT III Week 13 FIT III Assessment reports will be posted at: http://nodal.ercot.com/readiness/eds3/documents/index.htmlhttp://nodal.ercot.com/readiness/eds3/documents/index.html

11. Lead from the front Texas Nodal LFC10/19/2015 FIT SeriesWeekDateDay 1Day 2Day 3Convergence Avg % for all Test Hours 100% Convergence Achieved FIT IIWeek 1Oct 21 – 23, 200890.1874.1691.8385.3912 of 27 hrs Week 2Nov 04 – 06, 200888.1796.5897.1193.9518 of 27 hrs Week 3Nov 18 – 20, 200887.1784.1982.9184.7612 of 27 hrs Week 4Dec 02 – 04, 200896.0493.3393.4494.2714 of 27 hrs Week 5Dec 16 – 18, 200894.7497.4996.3096.1819 of 27 hrs Week 6Jan 13 – 15, 200996.0094.1295.7895.3015 of 27 hrs Week 7Jan 27 – 29, 200994.0790.1393.2992.4914 of 27 hrs FIT IIIWeek 1Feb 24 – 26, 200975.4578.8692.8582.3909 of 27 hrs Week 2Mar 10 – 12, 200996.8292.9798.4196.0720 of 27 hrs Week 3Mar 24 - 26, 200985.4594.9894.7091.7114 of 27 hrs Week 4Apr 07 - 09, 200997.1392.6097.4495.7221 of 27 hrs Week 5Apr 21 – 23, 200987.4789.8795.6591.0008 of 27 hrs Week 6May 05 – 07, 200994.3494.4791.8793.5613 of 27 hrs Week 7May 19 – 21, 200996.8197.3697.0497.0718 of 26 hrs* Week 8Jun 02 – 04, 200988.4784.0993.2988.6210 of 27 hrs Week 9Jun 16 – 18, 200997.4586.1495.5993.0613 of 27 hrs Week 10Jun 30 – Jul 2, 200994.9189.8986.6690.4911 of 27 hrs Week 11Jul 14 – 16, 200991.0184.7097.4991.0614 of 27 hrs Week 12Jul 28 – 30, 200995.9194.7393.6694.7718 of 27 hrs Week 13Aug 11 – 13, 200994.7294.6597.3795.5819 of 27 hrs FIT Update: Convergence Trends – FIT II & FIT III 11 * One hour was removed from the Week 7 test results to accommodate a nodal database load.

12. Lead from the front Texas Nodal LFC10/19/2015 FIT Update: Upcoming Nodal Telemetry Outreach 12 Nodal Telemetry Outreach  Beginning Aug 31, ERCOT will begin an Outreach effort to help MPs set up their remaining ICCP telemetry in time for Market Trials.  The Outreach effort will involve ERCOT working one-on-one with MPs to:  Identify remaining ICCP telemetry needed in nodal  Activate new ICCP points  Address ICCP clean-up issues Remaining 2009 FIT Windows: Outreach Begins (The 2009 FIT Calendar is posted at: http://nodal.ercot.com/readiness/eds3/documents/r6/eds_3_lfc_fit3_calendar_2009_v2.ppthttp://nodal.ercot.com/readiness/eds3/documents/r6/eds_3_lfc_fit3_calendar_2009_v2.ppt)

13. Lead from the front Texas Nodal LFC10/19/2015 FIT Update: Upcoming Nodal Telemetry Outreach (continued) 13 Nodal Telemetry Outreach (continued)  A mechanism for tracking and communicating the progress of the Outreach effort is being set up by ERCOT teams.  A Market Notice will be distributed the week of Aug 24 to provide MPs with more details about the Outreach effort.  After Aug 31, MPs may vet Outreach questions through the EDS3@eroct.com email box (please include “Nodal Telemetry Outreach” in the subject line).EDS3@eroct.com  Initial progress for the Outreach effort will be shared on the Sept 4 EDS Market Call. Remaining 2009 FIT Windows: Outreach Begins Initial Progress

14. Lead from the front Texas Nodal LFC10/19/2015 FIT Update: Upcoming Changes to FIT 14 Changes to FIT  ERCOT will discontinue Manual Replacements (MRs) during FIT windows.  During FIT III Wk 15 (Sept 8 – 10), ERCOT will stop providing MRs on Day Three of testing.  Starting with FIT III Wk 16 (Sept 22 – 24), ERCOT will discontinue MRs for the duration of the FIT III series.  The Market Notice to be distributed during the week of Aug 24 will include details about upcoming FIT changes (in addition to the details about the Outreach effort). Remaining 2009 FIT Windows: Initial Progress FIT with Manual Replacements FIT without Manual Replacements Outreach Begins

15. Lead from the front Texas Nodal LFC10/19/2015 FIT Update: Upcoming Key Dates 15 Upcoming Key Dates Week of Aug 24 ERCOT distributes a Market Notice to communicate details about the Outreach effort and changes to FIT. Aug 31 ERCOT begins the Outreach effort. After Aug 31 MPs may submit Outreach questions to EDS3@eroct.com with “Nodal Telemetry Outreach” in the subject line. EDS3@eroct.com Sept 4ERCOT shares initial progress for the Outreach effort during the Sept 9 EDS Market Call. Sept 10ERCOT discontinues MRs during FIT windows. Upcoming Key Dates for Nodal Telemetry Outreach and FIT Changes:

16. Lead from the front Texas Nodal Request for Market Participants to Improve Nodal EMS Data Submittals EDS Market Call August 21, 2009

17. Lead from the front Texas Nodal What: Need QSEs to improve Nodal EMS Data Submittals Any of the points listed here are not to indicate that they are optional for FIT windows Market Participant Telemetry Resources Net MW HSL, LSL HEL, LEL Resource Status Code All Ancillary Service Schedules and Responsibilities Resource Specific DSR Schedules and QSE DSR Load Regulation Participation Factors Combined Cycle Configuration Number Raise/Lower Block Status Essentially the ICCP data (as called for about year ago for the LFC testing) 17

18. Lead from the front Texas Nodal Data Submittals Regulation Responsibility Example – Zonal QSE has units providing Regulation Up in Zonal Zonal Regulation Up obligation equals 50MW for the hour Nodal (ICCP) Each Unit that is providing Regulation Up should have a Regulation Up Responsibility (ICCP) reflecting its actual responsibility assigned by the QSE in Zonal. The sum of the Regulation Up Responsibilities should equal the Zonal obligation, in this example that would be 50MW. A Regulation Up Participation Factor for each Unit must be sent to ERCOT. Basically the PF should be equal to the Regulation Up MW Deployed to Unit / Regulation Up MW Deployed to QSE. 18

19. Lead from the front Texas Nodal Data Submittals Other ICCP – Resource Output MW should be equal to current Zonal Resource Status Code must be correctly telemetered reflecting Zonal HEL, HSL, LSL and LEL should be updated to equal current Zonal Sum of QSE’s Responsive Reserve and Non-Spin Responsibilities should be equal to Zonal obligation The sum of the Dynamic Scheduled Resources Schedules Nodal should equal the sum of Dynamic Scheduled Obligations Zonal The sum of DSR schedules of all generation resources belonging to a given QSE should be equal to the DSR Load for that QSE QSE’s Responsive Reserve and Non-Spin Schedules should be equal to the Responsibilities (not expecting to deploy the AS) The current online combined cycle resources should match nodal combined cycle configurations 19

20. Lead from the front Texas Nodal When, Why and other info When do we need this? Starting September 15, 2009 we need “Quality Data” Monday thru Friday 0800 thru 1700. Why do we need this? Tremendous help to us as we work to get to the “Natural State” setup within our Nodal Itest Environment. ERCOT plans to use the data as input to internal testing. Other info Eventually will need ICCP data 24x7. That request is coming. NOT asking for bids, offers, and COPS. Nodal ICCP Data is non-binding for now 20

21. Lead from the front Texas Nodal Last slide Thank you. EDS3@ercot.com 21

22. Lead from the front Texas Nodal http://nodal.ercot.com 22 Q&A Q&A / Open Forum

23. Lead from the front Texas Nodal http://nodal.ercot.com 23 Appendix

24. Lead from the front Texas Nodal http://nodal.ercot.com 24 NODALTEST Certificates Expiration (originally presented 8/07/09)

25. Lead from the front Texas Nodal Standing reports and updates: Certificates (reminder) NODALTEST Certificate Expirations –All NODALTEST certificates will expire over the next several months –These certificates will not be renewed –In order to continue to test in the sandbox, MP’s may use any valid ERCOT certificate –When the Nodal Production environment is deployed in October, MP’s will use their current (zonal) certificate. –MP USA’s will need to add the appropriate Nodal roles depending on the testing that user will perform –Note: Nodal roles will not have an affect on zonal system usage

26. Lead from the front Texas Nodal http://nodal.ercot.com 26 Creation of the Nodal Implementation Team (originally presented 6/12/09)

27. Lead from the front Texas Nodal Standing reports and updates Program Update – Creation of the Nodal Implementation Team (NIT) –At its June 4, 2009 meeting, TAC created the Nodal Implementation Team (NIT) which will be a vehicle for stakeholder engagement in the Nodal program. –In preparation for the NIT initial meeting, the TPTF email distribution list has been discontinued and has been replaced by the NIT distribution list (NIT@lists.ercot.com)NIT@lists.ercot.com If you were previously subscribed to the TPTF distribution list, no action is needed as TPTF subscribers were automatically migrated to the NIT distribution list. If you were not previously subscribed to the TPTF distribution list and would like to subscribe to the NIT distribution list, please access the ERCOT distribution list management website at http://lists.ercot.comhttp://lists.ercot.com –Meeting materials, agenda, and WebEx information will be distributed as soon as they are available –First Meeting will take place on Monday, June 22, 2009 9:30 am – 4:30 pm –The NIT Charter was distributed via email to NIT@lists.ercot.comNIT@lists.ercot.com The charter is embedded below for your review:

28. Lead from the front Texas Nodal http://nodal.ercot.com 28 Review of Overall Registration Data Project Schedule (originally presented 5/22/09)

29. Lead from the front Texas Nodal http://nodal.ercot.com 29 Review of Overall Registration Data Project Schedule http://nodal.ercot.com 29 Each window will be broken into 3 iterations with heightening levels of data quality goals All non-PUN RE’s will submit during 1 of 2 windows (except Wind) Each non-PUN RE will request one of the two windows between 5/22/09 and 6/5/09 via email to nodalmarkettransition@ercot.comnodalmarkettransition@ercot.com Some RE’s may be moved to a different window based on volume Planning and Protection data will be rolled in for the remaining windows (see next slide) All Wind resources will submit during the second window 2009 MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Private Use Network Transmission Data Collection Window 1 - Non-Wind* RE’s Transmission / Planning / Protection Data Collection - Iteration 1 - Iteration 2 - Iteration 3 - Iteration 1 - Iteration 2 - Iteration 3 Private Use Network Planning and Protection Data Collection Window 2 - Wind RE’s Transmission and Planning / Protection Data Collection - Iteration 1 - Iteration 2 - Iteration 3 MP-10 Phase 2 Final Validation SEM GO-LIVE 8/31 EIS 1.19 to EDS 8/10 85% Prod Quality 95% Prod Quality 98% Prod Quality 85% Prod Quality 95% Prod Quality 98% Prod Quality 85% Prod Quality 95% Prod Quality 98% Prod Quality Kick Off Market Call

30. Lead from the front Texas Nodal Registration Data Collection Update Iteration 3 of the Private Use Network Transmission Data Collection closes on 5/19/09 Current Production Quality Metric is 96.5% (goal is 98% by 5/19) 5/22/09 9:30AM – 11:00AM ERCOT will host a kick off for the next leg of the Nodal Registration Data Collection project Changes to Load Resource Registration The kick off meeting will cover the following topics: –Transmission data collection (review for non-PUNs / non-Wind) –Planning and Protection data review (inclusive of Private Use Networks) –Review of registration activities for the remainder of 2009

31. Lead from the front Texas Nodal http://nodal.ercot.com 31 Nodal API sub-group Report, by Transaction, Completion Confidence (originally presented on 2/6/09)

32. Lead from the front Texas Nodal http://nodal.ercot.com 32 Standing reports and updates: Nodal API sub-group (originally presented on 2/6/09) TPTF Action – Report, by Transaction, Completion Confidence –Each Transaction will be classified into 3 confidence levels –RED – Confidence low – high risk of change in the 1.18 and/or 1.19 releases –YELLOW – Changes should be limited to non-structural changes (e.g. enumeration changes) –GREEN – Any Changes will be limited to defects. –Note that if there are no changes in 1.18 and significant change in 1.19, a transaction will be marked as RED for both. It will retain that color until all changes are complete.

33. Lead from the front Texas Nodal http://nodal.ercot.com 33 Standing reports and updates: Nodal API sub-group (originally presented on 2/6/09)

34. Lead from the front Texas Nodal http://nodal.ercot.com 34 Standing reports and updates: Nodal API sub-group (originally presented on 2/6/09)

35. Lead from the front Texas Nodal http://nodal.ercot.com 35 Verifiable Cost Submission (originally presented on 4/17/09)

36. Lead from the front Texas Nodal http://nodal.ercot.com 36 Verifiable Cost Submission (originally presented on 4/17) WMS Approved Verifiable Cost Submission Timelines: Simple Cycle Greater than 90MW June 30, 2009 Simple Cycle Less than or Equal to 90MW July 31, 2009 Gas Steam Non-Reheat Boiler Aug 31, 2009 Gas Steam Reheat BoilerSep 30, 2009 Gas Steam Super Critical BoilerOct 31, 2009 Combined Cycle Less than or Equal to 90MW Nov 30, 2009 Combined Cycle Greater than 90MW Dec 31, 2009 Coal, Lignite Jan 31, 2010 Nuclear, Hydro and Renewable Feb 28, 2010 Reciprocating Engines Feb 28, 2010

37. Lead from the front Texas Nodal http://nodal.ercot.com 37 Verifiable Cost Submission ERCOT plans to roll out verifiable cost training: Verifiable Cost Training will cover: –What are Verifiable Costs –What data need to be submitted –Who is required to submit the data forms and supporting information –Where, when and how are Verifiable Costs used Current Plans: –Instructor Led Training during May/June –One session each in Austin, Houston and Dallas Please send any comment to nodaltraining@ercot.comnodaltraining@ercot.com