1. http://nodal.ercot.com 1 Market Trials Open Market Participant Call Weekly Kick Off November 15, 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 This Week’s Activities – Soft Launch – 16 Days Until Go-Live RTM / LFC –Submissions representative of a post go-live scenario DAM / RUC –Submissions representative of a post go-live scenario –DAM will run daily based on protocol timelines –DRUC run daily –HRUC run hourly –SASM will run if necessary –REMINDER: Credit is set high for 11/15 and will be actual on 11/16 CRR - LIVE –11/15/2010 – December Auction Results Published –11/16/2010 – Locked Auction funds released –11/16/2010 – December monthly auction invoices posted to MIS –11/19/2010 – PCRRs allocated to NOIEs for January 2011 Monthly Auction –11/19/2010 – CRR network model posted for January 2011 auction –11/19/2010 – Monthly December CRR Invoices due Outage Scheduler - LIVE –Realistic outages for effective operational dates post Go-Live –Dual entry for 12/1/2010

4. Credit - Soft Start CMM Soft Start – Key Dates –November 15 th - Initial CMM reports generated and published –November 16 th – First DAM run with credit constraints –November 18 th – Zonal credit requirement from CMM system CMM Soft Start - General –Total Potential Exposure (TPE) will use a) Zonal data and b) binding Nodal data. No non-binding Nodal data (e.g. practice DAM runs) will be included in the soft start TPE calculations. Collateral included will be actual collateral held. –CPs participating in the DAM during the soft start will operate within a “real” ACL CPs should be working within real credit constraints preparatory to Go Live –Since the data used in the soft start TPE calculations is binding, ERCOT will use CMM exposures published beginning November 18 th as the bases for binding Zonal collateral requirements as well as Nodal “soft start” –ERCOT will produce Credit Reports and ACLs on non-business days during soft start Note: Please validate your Credit Reports this week. Please send questions to markettrials@ercot.com with a cc: to ercotcredit@ercot.com. markettrials@ercot.comercotcredit@ercot.com

5. Credit As CPs validate Credit Reports, please consider: –Highest ADTE Will reflect the highest ADTE of the last six weeks (will increase weekly to nine weeks) –AIL Zonal data will be included at a summary level only “Mismatched” volume is not displayed in the AIL report although imbalance dollars are correct (display issue only) –OUT – Adjusted for TCR revenues Reflects the same adjustment as in most recent Zonal report –OIA – Adjusted to reflect payments made on zonal invoices prior to due date (e.g. prepayments) –CRR invoices will be included in the Credit Reports on Tuesday or Wednesday, as they become available –CRR inventory will be included in the Credit Reports on Tuesday or Wednesday as it become available

6. 11/11 – 11/12 – Real-Time Hub SPPs and LZ SPPs http://nodal.ercot.com 6

7. 11/11 – 11/12 – Real-Time Hub SPPs and LZ SPPs http://nodal.ercot.com 7

8. 11/11/10 – 11/12/10 – Real-Time Market http://nodal.ercot.com 8 BARL SP

9. 11/11/10 – 11/12/10 – Real-Time Market http://nodal.ercot.com 9 W_TO_N SP W_TO_N Limit SNGTHW SP E1_M1 SP

10. http://nodal.ercot.com 10 24-Hour Full-System Market and Reliability Test (Nov 11 – 12)

11. http://nodal.ercot.com 11 24-Hour Test: Timeline DateApprox. TimeEvent 11/1109:30Pre-test meeting for Nodal Support Staff 10:00Hotline call by ERCOT Operators to announce the start time Kick-off of the Market WebEx Market Notice to be sent out with the test start time Operators to start using OC3s to manage congestion 12:00Hotline call to QSEs/TOs to announce the start of the test ERCOT Operators begin switching QSEs to Nodal control 12:03First QSE completed switch to nodal control 12:39All participating QSEs switched to Nodal control Hotline call to announce that all participating QSEs are on Nodal control 15:00Begin Emergency Base-Points (EMBPs) Operational Scenario EMBP scenario was moved to 9am on Nov 12 18:00-18:30ERCOT transition shifts to night-time support 20:00Recess Market WebEx 11/1206:00Reconvene Market WebEx 06:00-06:30ERCOT transition shifts to day-time support 09:00ERCOT Operators announce that they will begin EMBP Operational Scenario 09:17EMBPs issued by the ERCOT Operators 09:47EMBP flag de-activated ERCOT Operators announce that the EMBP planned operational scenario has ended 11:00Hotline call to announce that ERCOT will begin switching QSEs back to Zonal control 11:13First QSE switched back to Zonal control 12:02All QSEs on Zonal control Hotline call to QSEs/TOs to announce that the test has concluded

12. http://nodal.ercot.com 12 24-Hour Test: Observations Observations during the test: –EMS failover EMS failover occurred on 11/11 (approx. 2:41 pm) due to engineer action causing a critical SCADA process to crash EMS servers became unavailable for approximately two minutes Full functionality restored by approx. 2:45 pm with primary/stand-by server pair A defect has been logged to correct this issue –SCED performance Following switchover to nodal on 11/11 (approx. 12pm-3pm), Base Points were taking longer than normal to be distributed through SCADA EMS operating tables were optimized to address the issue Typical distribution times resumed at approximately 3:15 pm

13. http://nodal.ercot.com 13 24-Hour Test: Observations Observations during the test (continued): –Delays in distributing MMS-generated messages During testing, delays of up to two hours were seen in distributing MMS- generated XML messages Delays in messaging caused by performance related to high message volumes Delay issues were corrected by approx. 11/11 9:00 am –Increased the number of active jobs that can be running on MMS queues –Deployed configuration changes and two additional adapters to handle message volume –Began streamlining internal alert process around such performance issues to improve response time whenever performance issues occur

14. http://nodal.ercot.com 24-Hour Test: Completion Criteria At the close of the 24-Hour Test, an initial assessment will be provided of the following completion criteria : –The rolling CPS1 one minute average score must equal or exceed 100% during the test period Note that the CPS1 average will not take into account the periods where ERCOT is transitioning to Nodal and then back to Zonal Note that the CPS1 average will not take into account the periods where ERCOT is performing system tuning –Hourly CPS1 Scores: »Max: 158 »Min: 95 »Average: 137 –Zonal Commercially Significant Constraints (CSCs) and Closely Related Elements (CREs) managed below thermal limits: Yes –Local Congestion managed below thermal limits: Yes –Stability limits managed below transfer limits: Went above transfer limits on West to North stability limit, but were managed within the allotted timeline per NERC Standards. IROL not violated. –No NERC Disturbance Control Standard (DCS) failure if applicable: None –No LFC-SCED system issues that result in termination of the test: None