Market Trials Open Market Participant Call

1. Market TrialsOpen Market Participant Call Weekly Kick Off July 12, 2010 http://nodal.ercot.com 1

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. http://nodal.ercot.com 2

3. This Week’s Activities • RTM / LFC • Submit Energy Offer Curves to reflect Zonal BES Offers on Wednesday • Submit Energy Offer Curves 80-120% of costs for all other days • Reminder: 5-Hour Closed Loop / LFC test next week • Test will occur 7/20, 7/21 or 7/22 • Confirmation will be sent 2 business days prior to the test • Please send any updates to contact information to markettrials@ercot.com • DAM / RUC • Week 11 (of phase 5): DAM will run Monday through Friday • SASM will be run only when necessary • HRUC frequency will increase this week • DAM on Wednesday 7/14/2010 (operational date 7/15) • All QSEs encouraged to submit full set of transactions reflective of bidding/offer/contract/hedging behavior for DAM this day • In return ERCOT will provide a more detailed DAM solution analysis on the Friday Market Call • Objective is to focus on the quality of solution • CRR • 7/12/2010 – Bidding for August auction opens (note that eCollateral cut-off is noon today) • 7/12/2010 – Credit locks at 5pm • 7/13/2010 – ERCOT will post the 2011 – 2012 Annual Auction Notice • 7/15/2010 – Bidding for August auction closes • Outage Scheduler • Open testing continues until end of business 7/13/2010 • Realistic outages only after 7/13/2010 • Test Outages continue for effective dates Sunday, Monday http://nodal.ercot.com 3

4. Updates / Reminders • The CIM Model data load will be delayed • Will occur 1 day after the 5-Hour LFC test next week • Upcoming change to extract and report download file name format from MIS and EWS-Get Report - scheduled for 8/8/2010 • Market notice will be sent today with the new download format • Purpose is to ensure: • Consistency between all ERCOT download points - TML, Retail API, MIS, EWS • File name uniqueness for downloaded files • No change to the display file naming convention. Format will remain: ext.000RPTID.000000000000DUNS.yyyymmdd.hh24miss.Extract_Name.extension ext/rpt/cdr may be used in the first component of the file name. • New download file naming convention: ext.000RPTID.000000000000DUNS.yyyymmdd.hh24miss.Extract_Name.extension ext/rpt/cdr may be used in the first component of the file name. http://nodal.ercot.com 4