1. August 24, 2007 ERCOT Regional Planning Group Meeting CREZ Transmission Optimization Study Warren Lasher System Assessment

2. ERCOT Regional Planning Group Meeting August 24, 2007 Looking for 8 PUC Docket No. 33672 Began in January 2007 Parties nominated CREZs and demonstrated financial commitment –Most proposed CREZs based on the areas developed in the AWS Truewind study TSPs and potential TSPs put forth alternate transmission solutions Hearing on Merits held June 11-15 Decision on CREZ reached in late July; written order has not yet been issued, so some details are still unclear

3. ERCOT Regional Planning Group Meeting August 24, 2007 Your Mission, If You Choose to Accept It… Capacity of New CREZ Wind by Scenario (MW) Wind Zone Scen. 1 Scen. 2 Scen. JP Scen. 3 1, 21,2742,9176,0004,560 41,0392,38003,720 5, 68071,8493,0002,890 9, 101,4573,3365,0005,215 195731,31202,051 Total5,15011,79414,00018,436 Subject To Change

4. ERCOT Regional Planning Group Meeting August 24, 2007 The Process Will be conducted similar to the Regional Planning Group process, on fast-forward Frequent meetings will be held to discuss options, modeling, and results First meeting is scheduled for August 31 at the MET Center The RPG – CREZ mailing list will be used to distribute information associated with the study Participants will be expected to propose alternatives and to review each other’s proposed solutions Transmission solutions will be developed for the four scenarios outlined in the Interim Order –Higher-penetration scenario(s) will require some pre-work ERCOT will perform the independent assessment

5. ERCOT Regional Planning Group Meeting August 24, 2007 Project Timeline 123456789101112 Gridlines Represent 2-Week Periods Gather Options for Connections in CREZ Areas Stability Analysis Evaluate Options for System Connections Establish Mailing List and Set Meeting Schedule Modify Base Case for Higher Wind Scenarios Incorporate Results of A/S Study Review Results Evaluate System Upgrade Options for Higher Wind Scenarios ERCOT Review and Report Aug. 31Feb. 15

6. ERCOT Regional Planning Group Meeting August 24, 2007 Project Timeline 123456789101112 Gridlines Represent 2-Week Periods Gather Options for Connections in CREZ Areas Stability Analysis Evaluate Options for System Connections Establish Mailing List and Set Meeting Schedule Modify Base Case for Higher Wind Scenarios Incorporate Results of A/S Study Review Results Evaluate System Upgrade Options for Higher Wind Scenarios ERCOT Review and Report Aug. 31Feb. 15 Develop and Evaluate Options for CollectingWind Generation In CREZ Areas Survey stakeholders for proposals Develop multiple collection options for all 4 scenarios Will require discussion of direct connection issues within a CREZ

7. ERCOT Regional Planning Group Meeting August 24, 2007 Project Timeline 123456789101112 Gridlines Represent 2-Week Periods Gather Options for Connections in CREZ Areas Stability Analysis Evaluate Options for System Connections Establish Mailing List and Set Meeting Schedule Modify Base Case for Higher Wind Scenarios Incorporate Results of A/S Study Review Results Evaluate System Upgrade Options for Higher Wind Scenarios ERCOT Review and Report Aug. 31Feb. 15 ID Cong- ested Elements ID Potential System Solutions Evaluate Solutions Review results Revise Solutions Iterate this process until solutions are optimized Develop System-Wide Improvements (Scenarios 1, 2, and JP)

8. ERCOT Regional Planning Group Meeting August 24, 2007 Project Timeline 123456789101112 Gridlines Represent 2-Week Periods Gather Options for Connections in CREZ Areas Stability Analysis Evaluate Options for System Connections Establish Mailing List and Set Meeting Schedule Modify Base Case for Higher Wind Scenarios Incorporate Results of A/S Study Review Results Evaluate System Upgrade Options for Higher Wind Scenarios ERCOT Review and Report Aug. 31Feb. 15 The higher wind scenario(s) may require a modified evaluation process –May not be sufficient load in 2012 case to absorb the higher scenario(s) level of wind generation –Review generation operating assumptions

9. ERCOT Regional Planning Group Meeting August 24, 2007 Project Timeline 123456789101112 Gridlines Represent 2-Week Periods Gather Options for Connections in CREZ Areas Stability Analysis Evaluate Options for System Connections Establish Mailing List and Set Meeting Schedule Modify Base Case for Higher Wind Scenarios Incorporate Results of A/S Study Review Results Evaluate System Upgrade Options for Higher Wind Scenarios ERCOT Review and Report Aug. 31Feb. 15 Draft Results of the Ancillary Services study are expected in November Stability studies on scenarios 1 and 2 are expected to take 6 weeks

10. ERCOT Regional Planning Group Meeting August 24, 2007 Base Cases – Strawman Proposal Base transmission topology will be developed from the final year (2012) of the current Five-Year Plan –Latest Validated Case available –Derived from the 2007 SSWG Dataset B case –System Peak Load of 78,355 MW Wind patterns developed from AWS Truewind study Gas price: $7.00/MMBtu (delivered) Generation Fleet: Operating units and units with signed interconnection agreements As noted, the higher wind scenarios may require a modified evaluation process. Generation operations assumptions and load levels will be reevaluated for these scenarios.

11. ERCOT Regional Planning Group Meeting August 24, 2007 August 31 st Meeting Topics Discussion of direct connection and hub(s) placement Discussion of alternative “on-ramp” options List of issues

12. ERCOT Regional Planning Group Meeting August 24, 2007 On Your Mark… Sign up for the RPG - CREZ list at http://Lists.Ercot.com. Let me know if you have any questions (wlasher@ercot.com) Please participate in the process

13. Questions or Comments?