Lead from the front Texas Nodal 1 Registration Market Call Mar 27, 2009

Lead from the front Texas Nodal 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.

Lead from the front Texas Nodal 3 Agenda Antitrust Admonition Updates and Progress Special Topics Reminders Q&A / Open Forum ERCOT asks that you log into the WebEx using your company name then your name. This will allow us to take roll call offline. If you have not logged in with your company name, please use the WebEx chat to tell the host your company is represented

Lead from the front Texas Nodal 4 Updates and Progress Status for the past week: –Completed most conference calls with Private Use Network Currently the following RE’s are eligible for a conference call to review their RARF (have not yet held a call): –CALPINE CORP –SHELL OIL COMPANY –INVISTA SARL –GREGORY POWER PARTNERS LP –BP –Currently the Production Quality Metric is at 86% This is the baseline data provided previous to this iteration RARF’s Accepted: 0 of 23 (several in the last stage of modification) –Posted first Registration Dashboard for this phase last week Note that until further notice, this dash board will replace scorecard updates

Lead from the front Texas Nodal 5 Updates and Progress Where are we at? Final Calls with account managers and RE’s to take place next week Iteration 1 RARF’s are due by EOB than 4/2/09 Iteration 2 will begin 4/6 –All RE’s with remaining issues will be sent an audit report –If a RARF was not received for iteration 1, no additional report will be sent –If there are no remaining issues, an “Accepted for this Phase” will be sent to Authorized Representative at the Resource Entity. On the horizon (next meeting on 4/10/09) –Engaging the remaining RE’s for transmission data collection and approach –Discuss collection of Planning and Protection Data (final nodal registration data collection effort)

Lead from the front Texas Nodal 6 Special Topics – FAQ’s During Iteration 1 Define Master / Follower Transformer Configuration –In the case where AVR (Automatic Voltage Regulation) is employed on a transformer, another transformer may be set up as a “follower” –The regulated transformer will be the master –The follower transformer will follow the master’s tap steps If there are discrepancies between one-lines and the RARF what is the process? –The ERCOT Registration Team will Review internally with ERCOT Modeling –If there is not a clear directive on how to proceed, we will partner with the RE to make the appropriate modifications to the one-lines and RARF (See appendix slide 10 for general strategy on assets to be modeled)

Lead from the front Texas Nodal 7 Q&A Q&A / Open Forum

Lead from the front Texas Nodal 8 Q&A Appendix

Lead from the front Texas Nodal 9 Reminders Originally Presented on 3/13/09 ERCOT has published a revised RARF guide –The revised RARF guide contains all the business rules for transmission assets –The URL where this can be located is: –Document title: EDS - Resource Registration Guide v4.2 Scope of Transmission Data Assets (high level lists) –Lines –Breakers and Switches –Capacitors and Reactors –Transformers –Static Var Compensators –Series Devices –Loads –* PUN Load 168 hr Profiles *note that accepted PUN Load 168 hr Profiles will be added to the RARF upon re-submittal Those that still have issues with the PUN 168 profile form, ERCOT will work with you to correct on the conference with your account manager Out of Scope for this phase –Protection –SubSync –Planning

Lead from the front Texas Nodal 10 Reminders Originally Presented on 3/13/09 Clarifying statements on which assets need to be registered / modeled Note: This is specific to PUN’s. Specifics on other resource entities will be addressed on a later call –All assets which are between a generator and the point of interconnect to ERCOT –All Load Loads which are connected on a Bus greater than or equal to 60kV need to be modeled individually Loads connected at less than 60kV may be aggregated into an “equivalent load” at the 69kV Bus Auxiliary and Site Service Load may be combined Note: Auxiliary load is defined as that which is only present when the generator is running –In some cases it will be necessary for ERCOT and the Private Network to review specific assets and/or sites to make a determination on whether or not it is required to be registered / modeled These cases will be addressed during a WebEx coordinated by the RE’s Account Manager

Lead from the front Texas Nodal 11 Special Topics Originally Presented on 3/13/09 Issues Encountered on initial audit report group –Found that some validations were too “tight.” These have been relaxed Will be discussed on the conference call with your Account Manager if applicable to your audit report Example high / low side manufactured voltage on transformers was asking for levels at exactly 69,138 or 345 – it now allows up to 9% deviation from these levels (warns > 5%) –Data Pre-population issues Size of each step on transformer high/low tap settings calculated incorrectly –ERCOT will calculate this based on data provided by RE –This will be ignored if in error on the audit report Transformer Reactance / Resistance incorrectly calculated –ERCOT will provide correction to RE’s for first iteration 1 submittal Loads missing on Load tab –In cases where PUN’s have multiple substations under a site code, those substations that are not the same mnemonic as the site code did not populate the Load data. ERCOT will send the additional Loads left off