RELIABILITY AND OPERATIONS SUBCOMMITTEE Report to TAC Austin, TX December 1, 2011 Kenneth A. Donohoo, P.E. Chairperson Oncor Electric Delivery Company LLC

ERCOT TAC Meeting - ROS Report 12/01/2011 Ken Donohoo 2 TAC Voting Items NOGRR082, Synchronization with NPRR258 and Alignment of Primary Frequency Response Test Procedures – URGENT NPRR315, Revision of Responsive Reserve Measure to High Emergency Limit (formerly “Revision of Responsive Reserve Measure to Net Dependable Capability”) –ROS Rejected –Clayton Greer writing new NPRR

ERCOT TAC Meeting - ROS Report 12/01/2011 Ken Donohoo 3 ERCOT Board Resolution May 17, 2011 Board Resolution: THEREFORE be it RESOLVED, that the ERCOT Board hereby approves the revised ERCOT Business Practice, Setting the Shadow Price Caps and Power Balance Penalties in Security Constrained Economic Dispatch, as described in Attachment A to be effective on May 25, 2011, and directs the Technical Advisory Committee (TAC) to report back to the ERCOT Board on the following: (1) a recommendation for a holistic methodology for setting appropriate Shadow Price caps for constraints not resolvable by Security Constrained Economic Dispatch (SCED) and (2) a recommendation for addressing gaps between operations and planning processes to be able to identify constraints not resolvable by SCED.

ERCOT TAC Meeting - ROS Report 12/01/2011 Ken Donohoo 4 What are the operating/planning gaps? Thermal Generation Unavailability –Forced Outages/Derates –Ancillary Service –Environmental/Water Limits Wind –Low/High –Off Peak –Unavailability Operational Constraints/Limits Transmission Maintenance Outages Autotransformer Outages Dynamic Line Ratings Load Variability

ERCOT TAC Meeting - ROS Report 12/01/2011 Ken Donohoo 5 ROS Effort Special Meeting October 21, 2011 Significant Discussion at November 10 Meeting –Approved Recommendation developed by CenterPoint –Formed Task Force to continue examination and action items –Rejected PGRR011 and NPRR409

ERCOT TAC Meeting - ROS Report 12/01/2011 Ken Donohoo 6 SCR760 Status SCR Sub PartSCR DescriptionStatus SCR760-1Upgrade to PSS/E v32Planning SCR760-2Distribution Capacitor banksPlanning SCR760-3Zero Impedance Line RatingsProduction SCR760-4 Associate Loads and Capacitor banks with the correct CNG Planning SCR760-5Additional Transformer Data for PlanningPlanning SCR760-6FACTS DevicesSubmitted SCR760-7 Assign valid PSSE IDs to Breakers/ Switches/ Series Devices Production SCR760-8 Phase shift of Autos for short circuit studies Production SCR760-9Multisection Line GroupingPlanning Table 1: In the following table: Red will be used to show status of Not Submitted, meaning that the SCR sub part has not been submitted to Siemens as a Service Request. Yellow will indicate that the SCR sub part has been submitted. The color will remain yellow and the status will change in order to Submitted, Planning (Requirements, SOW, Code Writing), Release (Siemens produces first code to test), and Testing (code has completed internal test and is moving through release management). Green will indicate that the code has been tested and installed on the machines that ERCOT uses to produce Topology Processor output for Planning and CRR.

ERCOT TAC Meeting - ROS Report 12/01/2011 Ken Donohoo 7 SCR760 Status Status update on SCR760, Changes Needed for Information Model Manager and Topology Processor for Planning Models, which was approved by the ERCOT Board in March –Bundle 1 (Items 3, 7 and 8): In Production –Bundle 2 (Items 2, 4, 9): SOW signed by both Vendor and ERCOT. Expected code release in late November 2011 with production date of February 2012 on-cycle release. A Project Change Request is underway for Item 2 to allow additional functionality requested by TSPs. RAW file output for Item 9, Multi-section Line Grouping, created by vendor, was reviewed by ERCOT with positive results. Vendor starting work on part of Item 4, Associate Loads with correct CNG. Note: The other part of Item 4, Associate Capacitor banks with correct CNG, is now part of the change request for Item 2, Distribution Capacitor banks. Work estimates for change request due week of November 7th. –Item 5: Requirements completed by ERCOT and TSPs. Sent to Vendor for estimate. –Bundle 3 (Items 1 and 6): ERCOT and TSPs are updating document to identify new fields or records added between version 33 and version 30 of the PSS/E RAWD format. Began creating the evaluation process for Item 1 that would be added to SSWG Procedure Manual.

ERCOT TAC Meeting - ROS Report 12/01/2011 Ken Donohoo 8 ROS Next Meetings Thursday, Dec 8, 9:30 AM at ERCOT Austin