Protocol Revision Subcommittee Presentation to the ERCOT Technical Advisory Committee June 05, 2008

PRS Summary 6 PRRs for Approval 6 PRRs for Approval 4 NPRRs for Approval 4 NPRRs for Approval 2 Withdrawal Requests 2 Withdrawal Requests

PRR 757 –Emergency Interruptible Load Service Formula -- Normal Purpose(ERCOT) Correction to PRR 746 necessary to preserve clarity in the Nodal Protocols. Benefit Avoid confusion in Nodal Protocols. Market Impact N/A System Change NoN/A AssumptionsN/A PRS Vote PRS unanimously recommended approval; all Market Segments were present Effective Date August 1, 2008

PRR 757 –Emergency Interruptible Load Service Formula -- Normal Item Reviewed Description NoImpact Credit Monitoring/ Liability Budget Staffing Computer Systems Business Functions Grid Operations Impact

PRR 759 – Changes to Notification to Customer of Service Establishment - Normal Purpose(ERCOT) Better align ERCOT Protocols with PUCT substantive customer protection rules by discontinuing the Move-In notifications. Benefit Cost avoidance - $450M/year based on 2007 expenses Market Impact N/A System Change NoN/A AssumptionsN/A PRS Vote PRS unanimously recommended approval; all Market Segments were present Effective Date August 1, 2008

PRR 759 – Changes to Notification to Customer of Service Establishment - Normal Item Reviewed Description NoImpact Credit Monitoring/ Liability Budget Staffing Computer Systems Business Functions Grid Operations Impact

PRR 760 – EILS Availability Factor Clarification - Normal Purpose(ERCOT) Clarifies a settlement and compliance provision relating to availability requirements for EILS Resources assigned to the alternate baseline. Benefit Clarity in Protocol language for QSEs and EILS Resources Market Impact N/A System Change NoN/A AssumptionsN/A PRS Vote PRS unanimously recommended approval; all Market Segments were present Effective Date August 1, 2008.

PRR 760 EILS Availability Factor Clarification - Normal Item Reviewed Description NoImpact Credit Monitoring/ Liability Budget Staffing Computer Systems Business Functions Grid Operations Impact

PRR 762 West Zone SCE Performance Conditions – URGENT Purpose (AEP Service Corp.) Revises Section to exclude from consideration of performance periods where QSEs operating controllable units in the WEST Zone are called upon to deploy and recall Balancing Energy in response to high wind production and Congestion in the area. Benefit Increased availability of ramp rate to ERCOT OPS to resolve line overloads and reduce situations where higher cost Resources unnecessarily displace lower cost wind production. Market Impact N/A System Change NoN/A AssumptionsN/A PRS Vote PRS recommended approval with 1 opposing vote from Consumer Segment and 4 abstentions from Muni, IPM, IOU, and IREP ; all Market Segments were present Effective Date July 1, 2008.

PRR 762 WEST Zone SCE Performance Conditions - URGENT Item Reviewed Description NoImpact Credit Monitoring/ Liability Budget Staffing Computer Systems Business Functions Grid Operations Impact

PRR 763 Use of WGRPP as Planned Operating Level in Day-Ahead Resource Plan for WGRs – URGENT Purpose (ERCOT for ROS) Allows QSEs representing WGRs to use an ERCOT- provided Wind-powered Generation Resource Power Potential (WGRPP) forecast as the planned operating level in the Resource Plan. Benefit Gives ERCOT more visibility when performing capacity studies. Improves reliability of grid operations. Market Impact May affect amount of RPRS procured. System Change NoN/A AssumptionsN/A PRS Vote PRS unanimously recommended approval; all Market Segments were present Effective Date July 1, 2008

PRR 763 Use of WGRPP as Planned Operating Level in Day-Ahead Resource Plan for WGRs – URGENT Item Reviewed Description NoImpact Credit Monitoring/ Liability Budget Staffing Computer Systems Business Functions Grid Operations Impact

PRR 764 – Zonal Congestion and CSCs/CREs – URGENT Purpose (ERCOT for ROS) Provides that zonal constraints are only those constraints for which a CSC or CRE is the base case or post- contingency limiting element. Benefit More efficient management of congestion within the context and limits of the zonal market model. Market Impact Potential for less zonal congestion management and more local congestion management. System Change NoN/A AssumptionsN/A PRS Vote PRS recommended approval with 5 abstentions (MOU, Consumer, IPM, IG (2)); all Market Segments were present Effective Date TBD

PRR 764 – Zonal Congestion and CSCs/CREs – URGENT Item Reviewed Description NoImpact Credit Monitoring/ Liability Budget Staffing Computer Systems Business Functions Grid Operations Impact

NPRR 105 – Section 23, Synchronization of Zonal Protocols Purpose(ERCOT) Synchronize Zonal Protocol Section 23, Texas Test Plan Team – Retail Market Testing with the current Nodal Protocols. Benefit Synchronize Zonal/Nodal Market Impact N/A System Change NoN/A AssumptionsN/A PRS Vote PRS unanimously recommended approval; all Market Segments were present Effective Date Upon Texas Nodal implementation; no impact to nodal budget or implementation

NPRR 106 – Section 24, Synchronization of Zonal Protocols Purpose (ERCOT for TPTF) Synchronizes Zonal Protocol Section 24, Retail Point to Point Communications, with the current Nodal Protocols. Benefit Synchronize Zonal/Nodal Market Impact N/A System Change NoN/A AssumptionsN/A PRS Vote PRS unanimously recommended approval; all Market Segments were present Effective Date Upon Texas Nodal implementation; no impact to nodal budget or implementation

NPRR 109 – Section 18, Synchronization of Zonal Protocols Purpose(ERCOT) Synchronizes Zonal Protocol Section 18, Load Profiling with the current Nodal Protocols. Benefit Synchronize Zonal/Nodal Market Impact N/A System Change NoN/A AssumptionsN/A PRS Vote PRS recommended approval unanimously; all Market Segments were present Effective Date Upon Texas Nodal implementation; no impact to nodal budget or implementation

NPRR 110 – Section 20, Synchronization of Zonal Protocols Purpose(ERCOT) Synchronizes Zonal Protocol Section 20, Alternative Dispute Resolution Procedure with the current Nodal Protocols. Benefit Synchronize Zonal/Nodal Market Impact N/A System Change NoN/A AssumptionsN/A PRS Vote PRS recommended approval unanimously; all Market Segments were present Effective Date Upon Texas Nodal implementation; no impact to nodal budget or implementation

PRR/NPRR Summary Revision Requests Recommended for Approval Revision Requests Recommended for Approval PRR757 – EILS Formula Correction PRR757 – EILS Formula Correction PRR759 – Changes to Notification to Customer of Service Establishment PRR759 – Changes to Notification to Customer of Service Establishment PRR760 – EILS Availability Factor Clarification PRR760 – EILS Availability Factor Clarification PRR762 – West Zone SCE Performance Conditions PRR762 – West Zone SCE Performance Conditions PRR763 – Use of WGRPP as Planned Operating Level in Day-Ahead Resource Plan for WGRs PRR763 – Use of WGRPP as Planned Operating Level in Day-Ahead Resource Plan for WGRs PRR764 – Zonal Congestion and CSCs/CREs PRR764 – Zonal Congestion and CSCs/CREs NPRR105 – Section 23, Synchronization of Zonal Protocols NPRR105 – Section 23, Synchronization of Zonal Protocols NPRR106 – Section 24, Synchronization of Zonal Protocols NPRR106 – Section 24, Synchronization of Zonal Protocols NPRR109 – Section 18, Synchronization of Zonal Protocols NPRR109 – Section 18, Synchronization of Zonal Protocols NPRR110 – Section 20, Synchronization of Zonal Protocols NPRR110 – Section 20, Synchronization of Zonal Protocols

NPRR Withdrawals PRS accepted NPRR withdrawal requests for the following: PRS accepted NPRR withdrawal requests for the following: NPRR115 – Grey boxing of Settlement and Billing Related Information Calculation NPRR115 – Grey boxing of Settlement and Billing Related Information Calculation NPRR121 – System Parameters Posting Frequency NPRR121 – System Parameters Posting Frequency