1. http://nodal.ercot.com 1 Weekly Cutover Market Call Weekly Update November 24, 2010

2. 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. http://nodal.ercot.com 3 Full Market Trials Agenda General Updates and Reminders Cutover Updates by Functional Area Cutover Activity Review Question and Answers / General Discussion 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. http://nodal.ercot.com 4 General Updates / Reminders

5. http://nodal.ercot.com 5 General Updates and Reminders Network Model Load Dates 11/24/2010 – Completed as scheduled - Last update prior to Go-Live 12/15/2010 The Saturday 4:30 PM Market Call on 11/27/2010 will be canceled –Note that the 10:30 AM call on the same day will take place –Daily calls will resume as scheduled on Sunday 11/28/2010 REMINDER: Listener URLs –If there are any changes to your Listener URLs, submit those to ERCOT no later than today –Send changes to the nodalmarkettransition@ercot.com email addressnodalmarkettransition@ercot.com REMINDER: Frequency of polling data from ERCOT systems –All MPs need to review the frequency of which they are downloading / programmatically accessing data from ERCOT systems –ERCOT Support Teams are finding several MPs that are accessing reports at an unreasonable frequency –For example, some Daily Reports (generated once in a 24-hour period) are being hit 150,000+ times / daily by some QSEs –This will assist ERCOT in gauging post Go-Live performance and sizing / scaling of systems going forward to support reasonable data access behavior –If there are questions on the frequency of a particular report, MPs can access the ERCOT Market Information List (EMIL), currently posted at: (Under Key Documents): http://nodal.ercot.com/readiness/reports/index.htmlhttp://nodal.ercot.com/readiness/reports/index.html Revised ERCOT Business Practices Incorporating Guidance Related to Quick Start Generation Resource (QSGRs) –Revisions may be reviewed at http://www.ercot.com/mktrules/bpm/ http://www.ercot.com/mktrules/bpm/

6. NOVEMBER 2010 SUNDAYMONDAYTUESDAYWEDNESDAYTHURSDAYFRIDAYSATURDAY 123456 78910111213 1415 10:00AM – Market Call 1617 3:00PM – TSP Market Call 1819 9:00AM –Market Call 20 2122 10:00AM – Market Call 23 10:30AM / 4:30PM – Daily Market Call 24 10:30AM / 4:30PM – Daily Market Call 25 ERCOT HOLIDAY 26 ERCOT HOLIDAY 27 10:30AM– Daily Market Call Note that 4:30 PM Market Call canceled for this date 28 10:30AM / 4:30PM – Daily Market Call LFC Market Call 11:00AM – 5:00PM 29 10:30AM / 4:30PM – Daily Market Call *LFC Market Call 30 10:30AM / 4:30PM – Daily Market Call *LFC Market Call * LFC Market Call – Beginning at 6:00AM on 11/29 and continuing through 11:59 PM on 12/1 http://nodal.ercot.com 6

7. DECEMBER 2010 SUNDAYMONDAYTUESDAYWEDNESDAYTHURSDAYFRIDAYSATURDAY * LFC Market Call – Beginning at 6:00AM on 11/29 and continuing through 11:59 PM on 12/1 1 10:30AM / 4:30PM – Daily Market Call *LFC Market Call 2 10:30AM / 4:30PM – Daily Market Call 3 9:00AM –Market Call 4:30PM – Market Call 4 10:30AM / 4:30PM – Daily Market Call 5 10:30AM / 4:30PM – Daily Market Call 6 10:30AM / 4:30PM – Daily Market Call 7 10:30AM / 4:30PM – Daily Market Call 8910 9:00AM –Market Call 11 1213 10:00AM – Market Call 1415 3:00PM – TSP Market Call 1617 9:00AM –Market Call 18 1920 10:00AM – Market Call 212223 ERCOT HOLIDAY 24 ERCOT HOLIDAY 25 2627 10:00AM – Market Call 2829 3:00PM – TSP Market Call 3031 9:00AM –Market Call http://nodal.ercot.com 7

8. http://nodal.ercot.com 8 Day Ahead Market / Reliability Unit Commitment

9. DAM testing this week http://nodal.ercot.com 9 On average, 60 QSEs participated in DAM over this period

10. http://nodal.ercot.com 10 Submission Overview for Friday Nov 19 DAM submission overview 64 QSEs participated for Op Day 11/20 Energy Bids totaled 10,445 to 16,038 MW per hr Cleared 8,148 to 12,464 MW energy bids per hr Cleared 17,794 to 22,043 MW net energy transactions per hr - 66% to 78% of the forecasted load Cleared 12,445 to 13,634 PTP bids per hr Four major Load Zone prices ranged from $25.00 to $36.31

11. http://nodal.ercot.com 11 Submission Overview for Saturday Nov 20 DAM submission overview 52 QSEs participated for Op Day 11/21 Energy Bids totaled 7,156 to 9,983 MW per hr Cleared 6,424 to 8,624 MW energy bids per hr Cleared 15,843 to 18,227 MW net energy transactions per hr - 56% to 71% of the forecasted load Cleared 12,373 to 13,372 PTP bids per hr Four major Load Zone prices ranged from $15.60 to $25.60

12. http://nodal.ercot.com 12 Submission Overview for Sunday Nov 21 DAM submission overview 49 QSEs participated for Op Day 11/22 Energy Bids totaled 7,678 to 10,406 MW per hr Cleared 6,836 to 8,536 MW energy bids per hr Cleared 15,308 to 18,933 MW net energy transactions per hr - 50% to 68% of the forecasted load Cleared 11,429 to 13,569 PTP bids per hr Four major Load Zone prices ranged from $14.68 to $35.00

13. http://nodal.ercot.com 13 Submission Overview for Monday Nov 22 DAM submission overview 66 QSEs participated for Op Day 11/23 Energy Bids totaled 8,032 to 16,003 MW per hr Cleared 7,365 to 12,829 MW energy bids per hr Cleared 14,830 to 22,268 MW net energy transactions per hr - 54% to 73% of the forecasted load Cleared 11,915 to 15,434 PTP bids per hr Four major Load Zone prices ranged from $20.00 to $33.00

14. http://nodal.ercot.com 14 Submission Overview for Tuesday Nov 23 DAM submission overview 69 QSEs participated for Op Day 11/24 Energy Bids totaled 8,074 to 12,219 MW per hr Cleared 7,737 to 10,539 MW energy bids per hr Cleared 15,811 to 20,495 MW net energy transactions per hr - 51% to 65% of the forecasted load Cleared 12,956 to 17,638 PTP bids per hr Four major Load Zone prices ranged from $20.00 to $34.50

15. Binding Constraints in DAM http://nodal.ercot.com 15 ODCONTINGENCY_NAMECONSTR_NAMEMax Shadow Price 11/20/10SDUKNED8DUKE_NEDIN2_14.67 11/23/10SSCUSUN8MATA_PADR1_11.04

16. RUC testing this week http://nodal.ercot.com 16

17. Verifiable costs for go-live http://nodal.ercot.com 17 Note that approved verifiable costs for go-live have been added to the market system –As of this morning, all TPOs for 12/1 will be validated against the approved verifiable costs –TPOs submitted prior to this morning will be revalidated using the verifiable costs during phase 2 on 11/30

18. http://nodal.ercot.com 18 Real Time Market / LFC

19. Real Time Market Update http://nodal.ercot.com 19 11/23 System Lambda at SWCAP for 104 intervals BASE CASE W_TO_N DBRAVAL8 E1_M1_1 – Binding 12 pm – 4pm; 6pm – 7pm DGRSLNC5 6380_D_1 SORNLON8 SINTON_SKIDMO1_1 SSPUASP8 MATA_PADR1_1 – binding 12am – 3 am; 3pm – 9 pm 11/24 System Lambda at SWCAP for 14 intervals SBBSRCH5 1080__B – Binding 9am – 5pm SSPUASP8 MATA_PADR1_1 – not binding

20. Real Time Market Update http://nodal.ercot.com 20 Prices between $20 and $50 when not dispatched to SWCAP region

21. http://nodal.ercot.com 21 Alert that checks if EOC/OS exists when COP shows ONLINE: “SCED-TWOHR-FAIL Two Hour Notification: Check FAILED due to missing Output Schedules/Energy Offer Curves for Resource: XXXXXXX, Hour: 13 and Date: 11/24/2010”

22. http://nodal.ercot.com 22 Full-System Test / Nodal Cutover: Timeline Test Timeline: –ERCOT will conduct the Full-System Testing activities Nov 28 to Dec 1 Switchover is scheduled to begin at 14:00 on Nov 28 –ERCOT is requesting that support staff be available by 11:00 Sun., Nov 28, to resolve issues leading into the 14:00 start time Once all QSEs have been switched to nodal control following the 14:00 start time, the ERCOT system will remain on nodal control through the conclusion of testing activities on 23:59 CST on November 30, 2010, and into the beginning of the first nodal go-live Operating Day that begins at 00:00 CST on December 1, 2010 GREDP Results: –Individual GREDP results detailing the Nov 28 – 30 testing period will not be distributed following the testing –The first Monthly Resource Energy Deployment Performance Report (EMIL ID# NP8-501-ER) is scheduled to being publishing to MIS Certified on Jan 4, 2010

23. http://nodal.ercot.com 23 Full-System Test / Nodal Cutover: Communication Items Notices : –A Market Notice confirming the Nov 28, 14:00, start time was sent Nov 23 –A follow-up Market Notice will be sent two days prior to the actual test to confirm the date and start time –An additional Market Notice will be sent on Nov 28 to confirm the start time A hotline call will be made on the day of the test to communicate the start time of the test (approximately 2-3 hours prior to start) An All-QSE VDI will be issued immediately prior to the start of the test –The VDI will be define the “test period” to begin when the first QSE is brought under Nodal control and to end at 23:59:59 CST on Nov 30 Market WebEx: –A Market-facing WebEx will be provided during the following times: Nov 28 – 11:00 to 17:00 (six hours) Nov 29 – 06:00 to 23:59 (all day) Nov 30 – 00:00 to 23:59 (all day) Dec 01 – 00:00 to 23:59 (all day)

24. http://nodal.ercot.com 24 Full-System Test / Nodal Cutover: Timeline DateTimeEvent 11/2811:00Open Market WebEx 11:30Pre-test meeting for Nodal Support Staff 12:00Hotline call by ERCOT Operators to announce the start time Market Notice to be sent out with the cut-over start time Operators to start using OC3s to manage congestion 14:00Hotline call to QSEs/TOs to announce the start of cut-over ERCOT Operators begin switching QSEs to Nodal control 14:45All QSEs switched to Nodal control Hotline call to announce that all QSEs are on Nodal control 17:00Recess Market WebEx 18:00-18:30ERCOT staff transitions from day-side to night-side support 11/2906:00Resume Market WebEx 06:00-06:30ERCOT staff transitions from night-side to day-side support 18:00-18:30ERCOT staff transitions from day-side to night-side support 11/3006:00-06:30ERCOT staff transitions from night-side to day-side support 18:00-18:30ERCOT staff transitions from day-side to night-side support 12/100:00Nodal Market Go-Live/VDI for QSEs to end 06:00-06:30ERCOT staff transitions from night-side to day-side support 18:00-18:30ERCOT staff transitions from day-side to night-side support 23:59End Market WebEx

25. http://nodal.ercot.com 25 Full-System Test / Nodal Cutover: Switching Sequence Switching Sequence –The switching sequence from previous testing will be leveraged for this testing –This switching sequence is a guideline—the actual sequence may vary as needed to optimize reliability and manage congestion ZONAL to NODAL No.QSE/sub-QSE No.QSE/sub-QSENo.QSE/sub-QSENo.QSE/sub-QSE 1Nextera21Morgan SQ241EDF SQ4 - Eagle SQ461Optim 2Nextera SQ122Morgan SQ342ANP62Optim SQ1 3Nextera SQ223Morgan SQ443IPA SQ163PSEG SQ1 4Nextera SQ324Morgan SQ544Formosa64PSEG SQ2 5Nextera SQ425Bull Creek45MP2 Energy65Garland 6FPL Keir26EC and R SQ346J Aron SQ166Garland SQ2 7Luminant27Sweetwater 547EC and R SQ667Tenaska 8Luminant SQ128Pattern Gulf Wind48EC and R SQ768TRQ1 9Luminant SQ229Fulcrum SQ249Sherbino69TRQ4 10Luminant SQ330EC and R SQ150Silver Star70TRQ7 11CPS31EC and R SQ251BPTX SQ171TRQ9 12CPS SQ132EC and R SQ452Barton Chapel72Rio Nogales 13LCRA33EC and R SQ553Duke73Exelon 14AEN34Invenergy SQ154Edison Mission74Shell 15AEN SQ135Invenergy SQ255STEC75Shell SQ2 16NRG36Invenergy SQ356STEC SQ276Constellation 17NRG SQ137Invenergy SQ457AEP77Oxy 18Direct38Invenergy SQ558AEP SQ378BTU 19Direct SQ239EDF - Eagle59Calpine79Suez 20Morgan SQ140EDF SQ3 - Eagle SQ360Brazos80Xtend Energy 81IntelliGen Resources

26. http://nodal.ercot.com 26 Full-System Test / Nodal Cutover: Issues Management Issues Management: –From Nov 28 to Dec 1, issues will be fielded by testing support staff and through the Market WebEx –After Dec 1, issues will be fielded through the issues management process and during the twice daily market calls The issues management process is detailed in the slides for MRS #9 (http://www.ercot.com/calendar/2010/11/20101110-MT)http://www.ercot.com/calendar/2010/11/20101110-MT

27. http://nodal.ercot.com 27 Full-System Test / Nodal Cutover: ONTEST Status If you plan to be ONTEST for unit testing: –Confirm this intention with ERCOT by 4:00 pm the day prior to the Operating Day wherein ONTEST will be used –Note: The Request for Unit Testing can be found at http://www.ercot.com/mktrules/guides/procedures/index http://www.ercot.com/mktrules/guides/procedures/index To Be ONTEST on this Date:Confirm by 4:00pm on: Nov 28Nov 27 Nov 29Nov 28 Nov 30Nov 29 Dec 1Nov 30

28. http://nodal.ercot.com 28 Full-System Test / Nodal Cutover: Tuning Windows / Scenarios Market Participant Tuning Windows: –Market Participant system-tuning windows: Notify ERCOT of proposed tuning window by sending an email to markettrials@ercot.com by 12pm Sun., Nov 28, 2010 markettrials@ercot.com ERCOT will confirm whether other QSEs are conducting tuning activities during the proposed time and will suggest a different time if needed –Proposing that MPs do not perform tuning during the following test activities: Zonal  Nodal switchover activities Other QSE tuning windows No Operational Scenarios –ERCOT is not planning to conduct any operational scenarios during the testing window –Emergency Base Points and Non-Spin will be deployed as needed

29. http://nodal.ercot.com 29 Full-System Test / Nodal Cutover: EMBPs for Wind Emergency Base Points (EMBPs) for Wind –When EMBP is active, Wind Resources will be expected to follow their Base Point –When EMBP is active and W2N is active WGRs may receive special instructions to hold their last base point (depending on whether the IROL is active) ERCOT expects that this instruction will come as a hotline call For purposes of calculating GREDP, ERCOT does not consider the 5- minute clock intervals during which EMBPs have been issued (see NP 8.1.1.4.1 (6)(b))

30. http://nodal.ercot.com Full-System Test / Nodal Cutover: Deployments/AS Responsibilities Deployments: –During testing, QSEs will need to respond to SCED/Regulation/RRS/NSRS deployments from nodal –QSEs will still need to commit units based on RPRS results during Operating Days Nov 28 th, 29 th, and 30 th AS Responsibilities for Dec 1: –On Nov 30, ERCOT will update regulation calculations in LFC/RLC The LFC regulation calculation will be updated to honor 5-minute ramping The RLC calculations for SCED Up/Down Ramp rate will be updated to honor 5-minute ramping –ERCOT will make these updates at approximately 23:50 on Nov 30 –QSEs will be expected to update their telemetered AS Responsibilities, including Reg-Up and Reg-Down, to reflect DAM awards for HE 01:00 of Dec 1 Telemetry updates should be made no sooner than 15 seconds and not later than 4 seconds prior to 00:00

31. http://nodal.ercot.com Full-System Test / Nodal Cutover: Settlements Settlements: –As with previous testing, transactions during the Nov 28 – 30 test window will be settled according to the Zonal Protocols using Market Clearing Prices for Energy (MCPEs) calculated in the Zonal Market. See the following Zonal Protocol Sections: 6.8.2.3(2)(a) 6.8.2.3(5)(a) 7.4.3.1(1)(a) 7.4.3.2(a) –An All-QSE VDI will be issued immediately prior to the start of the test The VDI will be define the “test period” to begin when the first QSE is brought under Nodal control and to end at 23:59:59 CST on Nov 30 –Settlements will not calculate Uninstructed Resource Charges (URCs) during the test period (including the hour before the test period) –All QSEs will receive Schedule Control Error (SCE) exceptions during the test

32. http://nodal.ercot.com 32 Credit Update

33. Treasury Collateral and invoice payments received are posted same day –Collateral and invoice payments received before 12:00 noon will be included for the ACL available for the next day’s DAM (e.g. received by noon Monday will be reflected in Tuesday’s DAM ACL) –Collateral and invoice payments received after 12:00 noon will be included for the next day’s Credit Reports and the following day’s ACL (e.g. received after noon Monday will be reflected in Wednesday’s DAM ACL) Collateral reimbursement requests will generally be processed the next business day –Beginning December 1, refunds of collateral will be principal only (interest will not be included) –Interest will be paid semi-annually rather than in conjunction with each collateral refund http://nodal.ercot.com 33

34. Treasury On a due date, if an invoice payment has not been received, ERCOT plans to send out an e-mail reminder to QSE/CRRAH authorized rep and back up CP authorized rep and back up Credit contact and back up Note: Please be sure that ERCOT has updated contact information for your company – notices will be an automated process and will use the information in ERCOT’s Registration System. http://nodal.ercot.com 34

35. ERCOT continues to publish Credit Reports and ACLs daily, including non- business days CMM is now the system of record for Zonal credit requirements Total Potential Exposure (TPE) uses a) Zonal data and b) binding Nodal data. –No non-binding Nodal data (e.g. practice DAM runs) are included in the TPE calculations. Collateral included will be actual collateral held. –Some Zonal data will be included at a summary level only (e.g. AIL) or as adjustments (e.g. payment of Zonal invoices) CRR invoice payments were received and posted Note: If you have not already, please validate your Credit Reports. Please send questions to markettrials@ercot.com with a cc: to ercotcredit@ercot.com.markettrials@ercot.comercotcredit@ercot.com CMM - Credit http://nodal.ercot.com 35

36. CMM - Credit Shadow price caps approved for managing transmission congestion The board voted unanimously to approve shadow price caps and power balance penalties as recommended by the stakeholder committee process. As required by nodal protocols, ERCOT staff developed a methodology for setting maximum shadow prices for network constraints and power balance penalties under nodal. The shadow price caps – a market tool for managing transmission congestion on the grid – were used during the nodal market trials and performed as expected, ERCOT staff said.shadow price caps and power balance penaltiesrequired by nodal protocols ERCOT staff also noted that the shadow price methodology could allow prices to go above the current offer cap of $2,250 per megawatt-hour, as established by the PUC. The PUC-established offer price cap is scheduled to go to $3,000 per MWh, approximately two months after the nodal market go-live. Excerpt from press release on the November 16 th Board Meeting For full discussion see http://www.texasadmin.com/ercot.shtmlhttp://www.texasadmin.com/ercot.shtml http://nodal.ercot.com 36

37. CMM - Credit ERCOT systems require that all load requirements for an entity be met. In Nodal, load requirements can be met through a) Energy Trades –Must be confirmed b) the Day Ahead Market (DAM), c) Generation Resources that your QSE represents or through the d) Real Time (RT) market. Any load requirements not met through Energy Trade purchases, the DAM or your own Resources, will be met out of the RT market. –If an entity is a net buyer in the RT market in a period of high prices, exposure may escalate rapidly. Entities that intend to not be active in the RT market should ensure that their load requirement is met elsewhere Entities that intend to be net purchasers from the RT market, need to ensure that they have adequate liquidity to meet collateral requirements timely as exposure increases. http://nodal.ercot.com 37

38. CMM - Credit http://nodal.ercot.com 38

39. DAM - Credit DAM credit parameters are set as they will be set for Go Live –DAM is currently using the 90 th percentile for both the “uth” parameter and the RT DA spread (as approved by the BOD) DAM historical values used for credit constraints “e” factors are set to 1/0/1 –Will be effective through operating day - December 14 th –Notices go out by two methods E-mail to CP authorized rep and back up and CP Credit contact and back up is the primary communication tool Written notices went out by regular mail CPs desiring “favorable treatment” should complete and return the Request for Change in “e” Factor Treatment Form to ercotcredit@ercot.comercotcredit@ercot.com http://nodal.ercot.com 39

40. Go Live CMM Go Live – Key Dates –Monday, November 29 th - Send ACL for initial binding DAM (afternoon) (TPE excludes zonal invoice published on November 29 th ) –Tuesday, November 30 th - Initial binding DAM - “e” factors set at 1/0/1 - Credit Report include zonal invoice published on Nov 29 th –Wednesday, December 1 st – “Go Live” CMM Go Live – General –See Appendix for detail of how exposure components will be addressed. December 1-3 - “ramp up" for DALE - multiply the UDAA by a factor of five (5) each day until the first DAM invoice is published. December 4-5 (Sat/Sun) - discount DALE by 25% since the first DALE is calculated on a weekend. DALE will be calculated at 100% beginning with Credit Reports posted Monday, December 6, 2010 and ACLs sent Monday evening for Tuesday, December 7, 2010. See slide on expected impact of ACP on FMM in FCE calculation –If a Counter-Party believes that their Zonal ADTE is not representative of their anticipated Nodal RT activity, they can provide an estimate of anticipated RT activity and ERCOT will consider revising their ADTE. http://nodal.ercot.com 40

41. http://nodal.ercot.com 41 Cutover Update

42. MP Activities / Impacts Available Credit Limit is locked for CRRAHs CRRAHs can submit disputes against CRR Auction Invoice via the API or MIS CRRAHs can receive postings on MIS QSEs can begin DAM Bid submission (15 submission items) Market checkpoint calls begin to facilitate issues and readiness Daily Market Conference Bridge starts 11/23 Functional Area Settlements Credit Congestion Revenue Rights Disputes Market Management MayJuneJulyAugSeptOctNovDec Cut-Over Monthly Outlook – November Key Cut-Over Activities for November 2010 (11/8/2010 12:00pm) Credit: Collateral Posting Deadline (Dec Auction) (11/8/2010 5:00pm) CRR: Credit Lock for Dec CRR Auction (11/9/2010 – 11/11/2010) CRR: December CRR Auction Bid Open/Close (11/12/2010) CRR: December CRR Auction Executes (11/15/2010) CRR: December CRR Auction Results published (11/16/2010) Settlements: December CRR Auction Invoice published (11/16/2010) Disputes: Dispute submitted to ERCOT for CRR Invoice (11/19/2010) Credit: Payment Due for December CRR Auction Invoices (11/22/2010) Settlements: Payments to CRRAH (Dec Auction) (11/24/2010) Model: Network Model Load (11/24/2010) Market Submission Opens (COPs required for 12/1/2010) (11/29/2010) Credit: ERCOT to Publish ACL for the initial Day-Ahead Market execution by ERCOT http://nodal.ercot.com 42

43. Cut-Over Update – Go-Live Sequence of Events DateActionComments 11/15/2010 – 11/29/2010 ERCOT Initiates “Soft Launch” to Nodal Market Go-Live ERCOT will run non-binding DAM, RUC daily per Nodal protocol timelines. RTM will remain Open Loop, but continue to publish base points and LMPs. Note that credit will be set high on 11/15 11/15/2010 Credit posts ACLs and TPEs for non- binding DAM For Operating Day 11/15 credit will be manually set to high limits 11/16/2010First Credit Operating Day 11/16Credit reflects actual limits 11/17/2010 Market now able to submit transactions for first Nodal Operating Day (T-14d) 12/01 Operating Day open for Market submissions 11/24/2010 QSEs with Resources required to submit 7 days of rolling COPs 12/01 required on 11/24 11/28/2010 2:00 PM – 11/28/2010 3:00 PM Generation and Frequency Control switched to Nodal systems for final LFC test QSEs will begin following Nodal base points Settlements will continue to be Zonal 11/28/2010 2:00 PM – 11/30/2010 11:59:59 PM QSEs remain on Nodal Control while settling Zonally during the LFC test 11/29/2010 Last Non- Binding DAM for operating day 11/30 http://nodal.ercot.com 43

44. Cut-Over Update – Go-Live Sequence of Events (11/30/2010) TimeActionComments up to 10:00 Bids and Offer submission QSE submit bids and offers 10:00 Close DAM 10:00 Execute Dam Clearing Process 13:30 Approve DAM resultsDay Ahead results posted to MIS 13:30-14:30 Submit Post DAM COP updates 14:30 Close for RUC 14:30 Begin Execution of DRUC 16:00 Approve DRUC Results 16:00 Post DRUC Results 18:00 HRUC Begins Hourly Runs http://nodal.ercot.com 44

45. http://nodal.ercot.com 45 Questions

46. http://nodal.ercot.com 46 Appendix

47. Approach for establishing the initial exposure in CMM http://nodal.ercot.com 47

48. Approach for establishing the initial exposure in CMM http://nodal.ercot.com 48

49. Approach for establishing the initial exposure in CMM http://nodal.ercot.com 49

50. Go Live – FMM calculation http://nodal.ercot.com 50

51. Cut-Over Update – Go-Live Sequence of Events DateActionComments 11/15/2010 – 11/29/2010 ERCOT Initiates “Soft Launch” to Nodal Market Go-Live ERCOT will run non-binding DAM, RUC daily per Nodal protocol timelines. RTM will remain Open Loop, but continue to publish base points and LMPs. Note that credit will be set high on 11/15 11/15/2010 Credit posts ACLs and TPEs for non- binding DAM For Operating Day 11/15 credit will be manually set to high limits 11/16/2010First Credit Operating Day 11/16Credit reflects actual limits 11/17/2010 Market now able to submit transactions for first Nodal Operating Day (T-14d) 12/01 Operating Day open for Market submissions 11/24/2010 QSEs with Resources required to submit 7 days of rolling COPs 12/01 required on 11/23 11/28/2010 2:00 PM – 11/28/2010 3:00 PM Generation and Frequency Control switched to Nodal systems for final LFC test QSEs will begin following Nodal base points Settlements will continue to be Zonal 11/28/2010 2:00 PM – 11/30/2010 11:59:59 PM QSEs remain on Nodal Control while settling Zonally during the LFC test 11/29/2010 Last Non- Binding DAM for operating day 11/30 http://nodal.ercot.com 51

52. Cut-Over Update – Go-Live Sequence of Events (11/30/2010) TimeActionComments up to 10:00 Bids and Offer submission QSE submit bids and offers 10:00 Close DAM 10:00 Execute Dam Clearing Process 13:30 Approve DAM resultsDay Ahead results posted to MIS 13:30-14:30 Submit Post DAM COP updates 14:30 Close for RUC 14:30 Begin Execution of DRUC 16:00 Approve DRUC Results 16:00 Post DRUC Results 18:00 HRUC Begins Hourly Runs http://nodal.ercot.com 52

53. Cut-Over Monthly Outlook – Go-Live Sequence of Events Key Zonal Notes for 11/30/2010 and 12/01/2010 –QSEs will maintain: Balancing Energy Offers through Operating Day 12/01/2010 –Submitted on 11/30 for OD 12/1 Resource Plans through Operating Day 12/01/2010 –Maintained continuously through 12/01 to reflect actual Resource Plan Zonal Outages effective on Operating Day 12/01/2010 –Examples: Actual Start / End, Forced Outages, etc –On 11/30/2010 ERCOT will run: Zonal Ancillary Service Market –Zonal awards will be published Zonal RPRS –Run as a study only –Zonal commitments will not be published –Zonal prices will not be generated for 12/01/2010 –No Zonal Submissions or Markets for Operating Day 12/02/2010 or later –Note that all Zonal systems (ERCOT and MP) must remain in place until 1/1/2011 http://nodal.ercot.com 53