Oncor Electric Delivery Company LLC RELIABILITY AND OPERATIONS SUBCOMMITTEE Report to TAC Austin, TX March 4, 2010 Kenneth A. Donohoo, P.E. Chairperson Oncor Electric Delivery Company LLC

Nodal Model Effort Activity Operations Model (NMMS) Topology Processor (Software) CRR Model Long Term Planning Model NDSWG Support Significant Effort Good Shape Improving Under Development Outputs 12/15/2009 02/24/2010 Updates Continuing Full Functionality Needed SSWG Support Significant Complex Work To Complete SSWG Support Additional Capability Needed To Meet Planning Needs Development Delayed 03/04/2010 Ken Donohoo ERCOT TAC Meeting - ROS Report

Nodal Model Effort Activity NDSWG, SSWG and ERCOT Staff Partners in Effort Coordinating Well Communications Improving Developing solutions Very complex translating different environments Software tool(s) need further improvement, speed and capability Everyone committed to meet Nodal Implementation Continuous effort required to maintain databases Complete coordination of operating and planning databases is the goal Current and new NERC standards may require further operations and planning model changes to support required analysis 03/04/2010 Ken Donohoo ERCOT TAC Meeting - ROS Report

TAC Voting Items SCR 758 - Enhancements to the Proposed Transmission Outage Report ROS unanimously voted to endorse 03/04/2010 Ken Donohoo ERCOT TAC Meeting - ROS Report

ROS Activities Recognize the changing nature of the ERCOT grid Frequency and voltage control (reactive) concern Improvement to operating and planning data Development of Planning Guides and Planning Working Group (PLWG) Increases focus on planning activities Bring all planning related documents together Increase transparency and communication Use same change control process as Protocols with approval to ERCOT Board Include planning charter, generation interconnect procedures, criteria and procedures Consolidate several separate working groups under the new working group 03/04/2010 Ken Donohoo ERCOT TAC Meeting - ROS Report

ROS Issues and Action Items Expansion of Series Capacitors (Compensation) and Possible Interactions with Power System Elements Operations Reactive Power and Voltage Control Planning Reactive Power Analysis Renewable Integration Reduced Load Level Analysis Off Peak modeling (MW and Mvar) and cases Stability Analysis Models and Data (includes RARF) NMMS (MOD) Implementation in Planning Environment Planning Compliance Coordination Integration of new standards in criteria and guides Smart grid incorporation in planning and operations Generator expectation communication and certification Energy Efficiency and loss reduction Creation of Planning Guides and Working Group (PLWG) Consolidation of working groups Automation of PDCWG analysis 03/04/2010 Ken Donohoo ERCOT TAC Meeting - ROS Report

ROS Next Meeting Thursday, March 11, 9:30 AM at ERCOT Austin Voting Items: Create Planning Working Group and Develop planning guides PDCWG Procedures Disband WOTF and LTSTF PRR833, Primary Frequency Response Requirement from Existing WGRs OGRR232, Revise the Process for Submitting Biennial Unit Reactive Limits (Lead and Lag) NOGRR027, Revise the Process for Submitting Biennial Unit Reactive Limits (Lead and Lag) OGRR240, CREZ Facility Protection and Control Requirements OGRR242, Section 7 System Protections Revisions to Meet Pending NERC Requirements for New Construction Nodal Model Effort CREZ Reactive Study Update – ABB Presentation 03/04/2010 Ken Donohoo ERCOT TAC Meeting - ROS Report