February 3, 2011 TAC ERCOT Planning Go-Live Update Jay Teixeira Manager, Model Administration

2 TACFebruary 3, 2011 For ERCOT, Planning Go-Live means using the output from NMMS Topology Processor case as the “seed” into the NMMS Model on Demand (MOD) system to build Annual Planning Cases to comply with Protocol This system will be designated “TP-MOD”. For TSPs, Planning Go-Live means using an existing SSWG case as the “seed” into MOD to build SSWG Planning cases and resolving or documenting the differences between the SSWG-MOD case and the Topology Processor processed case. This system is designated “SSWG-MOD”. For both systems, some parts of SCR760 are desirable. What does Go-Live mean?

3 Protocol Required Annual Planning Model vs SSWG Cases TACFebruary 3, 2011 Created by SSWG and ERCOT Approved by SSWG TSPs allowed to model facilities as they please 78% Consistent with TP output Annual Planning Models 5 Summer Peak Cases SSWG Cases Data Set A 1 Summer Peak Case 7 Others Data Set B 5 Summer Peak Cases 1 Other Created and Approved by ERCOT TAC Approved Rules of Consistency Apply 100% Consistent with TP output No topology changes allowed from TP output case without corresponding NOMCR submittal

4 5 SSWG Cases were going to be Annual Planning Models (Option 1) TACFebruary 3, 2011 Annual Planning Models 5 Summer Peak Cases SSWG Cases Data Set A 1 Summer Peak Case 7 Others Data Set B 5 Summer Peak Cases 1 Other ERCOT and SSWG were going to build the current set of SSWG cases and use the 5 Summer Peak Cases as the 5 Annual Planning Model cases except: Rules of Consistency Apply Had to start with TP output Changes not allowed that altered the branch consistency between models All SSWG cases were to be built using TP-MOD

5 ERCOT will take lead in building Annual Planning Models as specified in Protocol TACFebruary 3, 2011 TP-MOD Environment Identified as Option 1 in ROS January 13 th meeting ERCOT will build parallel to SSWG process with assistance from TSPs as required by Op Guide 5.5 ERCOT will assume responsibility to meet timelines Annual Planning Models 5 Summer Peak Cases Starting with next year summer peak case to be completed by Oct 15 th per Protocol Created and Approved by ERCOT TAC Approved Rules of Consistency Apply 100% Consistent with TP output No topology changes allowed from TP output case without corresponding NOMCR submittal

6 ERCOT will add second MOD environment so that SSWG can build their cases TACFebruary 3, 2011 SSWG Cases Data Set A 1 Summer Peak Case 7 Others Data Set B 5 Summer Peak Cases 1 Other SSWG-MOD Environment Identified as Option 2 in ROS January 13 th meeting SSWG will build cases in accordance with SSWG procedures with assistance from ERCOT SSWG will assume more direct responsibility to meet timelines and build cases ERCOT will supply dispatch Created by SSWG and ERCOT Approved by SSWG TSPs allowed to model facilities as they please Move towards increasing consistency with Option 2 comparison with TP as mandated by ROS

7 Block Diagram of ERCOT Proposal TACFebruary 3, 2011

8 SSWG Presented with Proposal TACFebruary 3, 2011 At the regularly scheduled SSWG Conference Call on Jan 26, 2011 – ERCOT presented the dual MOD environment to SSWG for the first time. SSWG raised some concerns and requested more time to review. Among the concerns raised: Having 2 sets of planning cases could open ERCOT and TSPs to demonstrate NERC compliance with both sets of cases. There are no NERC requirements for the Planning Authority and Transmission Planner to use the same cases to demonstrate compliance. Whichever cases the Transmission Planner uses to plan its system, those are the cases they will use for NERC. Wanted clarification on ERCOT and TSP responsibilities for both systems. Some TSPs still want to eventually go to the TP-MOD system and have only one set of planning cases. Other TSPs needed more time to look at the proposal.

9 ERCOT Responsibilities TACFebruary 3, 2011 Maintain two MOD environments – TP-MOD and SSWG-MOD Load base cases into both environments Submit ERCOT Generation dispatch to both environments Copy TSP submitted Load and Device Control profiles from SSWG-MOD environment into TP-MOD environment and translate as necessary Copy TSP submitted Planning Model Change Requests (PMCRs) from SSWG-MOD environment into TP-MOD environment and translate as necessary Use SSWG Pass 0 comparison introduced at ROS Jan 13, 2011 meeting to translate profiles, PMCRs, and contingencies if necessary from TSP submission to SSWG-MOD environment to TP-MOD Maintain timeline for case completion in TP-MOD Compare SSWG-MOD and TP-MOD contingency results and resolve

10 TSP Responsibilities TACFebruary 3, 2011 Submit Load and Device Control profiles into SSWG-MOD environment Submit future Planning Model Change Requests into SSWG-MOD environment Complete Pass 0 comparison with Topology Processor case as introduced at ROS Jan 13, 2011 meeting Maintain timeline for TSP data submission and case completion in SSWG-MOD Submit contingency list for SSWG-MOD environment Compare SSWG-MOD and TP-MOD contingency results and resolve

Questions February 3, 2011TAC