Market Trials Real-Time Market / LFC

1. Market TrialsReal-Time Market / LFC Weekly Update September 3, 2010 http://nodal.ercot.com 1

2. Agenda • Antitrust Admonition • Known Issues • Standing Reports and Updates • General reminders / updates • Real Time Market / LFC Update • State Estimator Convergence Statistics • 48 Hour Full System Market and Reliability Test Update • 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 http://nodal.ercot.com 2

3. Known Issues Recently Open • Report retry functionality is not retrying for the correct missed intervals • Affects CDR • Estimated fix date: mid September • SPP and LMP reports • When a report query returns empty, there is currently no mechanism to indicate whether the failure is due to no data or due to a pending CDR retry • Updates to Tracking Artifacts • The Known Issues tracking sheet will refresh overnight to the Readiness center at http://nodal.ercot.com/readiness/markettrials/rtm/index.html\ • Update will be given on the Tuesday Market Call http://nodal.ercot.com 3

4. Standing Reports and Updates: General Reminders / Updates Reminders/Updates • Load Resources RRS Deployment Test • First test conducted 8/30-8/31. Detailed results will be communicated on the next Real-Time Market Call. • Due to the Holiday week of 9/6 and the 168 hour test week of 9/13, the next Load Resources RRS Deployment Test will be held on Monday (9/20) and Tuesday (9/21) • Delays in posting GREDP results for the 40-Hour Test and SE Convergence data • Internal Issue encountered with ERCOT’s data replication software that replicates EMS data • EMS applications have still performed with no data loss, but data replication is lagging into system from which GREDP results are extracted • An update will be given on Monday Market Call http://nodal.ercot.com 4

5. Real Time Market / LFC Update 1/3/2020 http://nodal.ercot.com 5

6. Real Time Market / LFC Update • SCED Week 30 • Faulty telemetered generation caused at least an additional amount of false demand, which in turn caused energy offer insufficiency (undispatchable generation). • Under generation situation caused LMP spikes, which set the System Lambda to the penalty cost of $3,001/MWh. 8/26 8/27 8/28 8/29 8/30 8/31 9/1 http://nodal.ercot.com 6

7. Real Time Market / LFC Update 24 #1 Hour LFC Test (8/4-5) 24 #2 Hour LFC Test (8/19-20) 40 Hour LFC Test (8/26-28) http://nodal.ercot.com 7

8. State Estimator Convergence http://nodal.ercot.com 8

9. State Estimator Convergence Update * Please note, due to data replication issue from EMS to ISM, SE convergence data for 8/28-9/1 is not included. See detail in “general reminders/updates” section of the presentation. http://nodal.ercot.com 9

10. State Estimator Convergence Update http://nodal.ercot.com 10

11. 48-Hour Full-System Market and Reliability Test(Sep 12 – 14) Stacy Bridges http://nodal.ercot.com 11

12. 48-Hour Test Test Timeline http://nodal.ercot.com 12

13. 48-Hour Test Overview – Tuning Windows • Proposed Tuning Windows • ERCOT system-tuning windows: • ERCOT does not plan to do any system tuning during this test window • Market Participant system-tuning windows: • Notify ERCOT of proposed tuning window by sending an email to markettrials@ercot.com • ERCOT will confirm whether other QSEs are performing during the proposed time and will suggest a different time if needed • Proposing that MPs who wish to perform system tuning do so during times that do not overlap with the following test activities: • ZonalNodal /Nodal Zonal switchover activities • Other QSE tuning windows http://nodal.ercot.com 13

14. 48-Hour Test Operational Scenarios • At this time, ERCOT is not proposing any operational scenarios to be conducted during the Sep 12 – 14 test window • If any scenarios are added to the test timeline, they will be communicated as soon as possible ahead of the Sep 12 – 14 test window Shutdown Activities • RST during Shutdown: • To shutdown during testing, change your RST to ONTEST • The RLC will then set LDL=HDL=Net Real Power=Base Point, and the SCED Base Points will follow the output of the Resource down to the point that it is removed from the grid Full-System Testing Slide Deck • The running workshop slide deck describing the details of full-system testing is available in Key Documents on the meeting detail at http://www.ercot.com/calendar/2010/09/20100903-MT http://nodal.ercot.com 14

15. 48-Hour Test Requesting Updates to Nodal Contacts for 48-Hour LFC Test • QSEs with Resources are requested to review their Nodal Contact information as previously submitted per the Contact Declaration Form and make any necessary changes for contacts who will be supporting ICCP, LFC, Market Data Submittals • The current Nodal Contact Declaration Form v1.1 is available at http://nodal.ercot.com/readiness/rq/documents/index.html • Submit any updates or questions to nodalmarkettransition@ercot.com by 12:00pm on Sep 9, 2010 • In addition, please ensure that the contact information for your Real-Time desk is accurate so that the ERCOT Control Room can contact you as needed during the 48-Hour LFC Test http://nodal.ercot.com 15