1. Nodal Planning Model Process and Data Set A case use June 28, 2010 Planning Working Group

2. 2 February 11, 2010 Planning Model Go-Live Time line

3. 3 Flow Chart of Case Building Process February 11, 2010 1.ERCOT Planning imports the base case from NMMS (Topology Processor) quarterly (and as needed) 2.Generation, Load, and Reactive Profiles need to be created by ERCOT and TSP for each case that will be created. These are added to Topology Processor case in Model on Demand (MOD) – very similar to current case building effort 3.Future Topology changes are added to these cases by Planning Model Change Requests – PMCR’s – similar to current IDEV’s. 4.ERCOT/SSWG Validates these data sets using PSSE 1 23 3 4

4. 4 TPTFMarch 20, 2008 Issues/Challenges 1.Entry of Planning Data into IMM more complicated and taking longer than anticipated Went from 1000 bad Connectivity Node Groups to 300 quickly Last 300 very hard to fix IMM entry hindered by technical problems ERCOT has created spreadsheets to batch load data on behalf of TSP’s (PSSE_ID for loads, lines, shunts, etc.) 2.MOD Issues Number of standard PMCR’s for MOD more complicated due to IMM schema (fields need to be added, load schedules for Shunt Devices, acLineSegment name length) Creating profiles for generation, load, and reactive schedules will consume as much time as current case building effort until we get more experience with MOD and get schema changes Vendor issues with software releases and fixes taking longer and causing new or previous problems to appear 3.Nodal work in addition to regular schedule Zonal case building following normal schedule TPIT updates has followed normal schedule but will lighten in July and October to allow time for testing MOD and Building Data Set B Training and maintaining the MOD system, answering questions will require more time as we transition to nodal

5. 5 TPTFMarch 20, 2008 Data Set A Uses ERCOT Use DS A Case Used Determining Flat load for Near Term congestion and 5 year plan cases Uses all 8 cases for range of load level. SPS ReviewsCan use any of all 8 cases depending on SPS under study and time frame RMR AnalysisCan use any of all 8 cases depending on RMR unit under study and time frame Transmission Loss Factor CalculationsUses generation, load, losses from all 8 cases Near term congestion analysisUses summer peak topology ERCOT Operations requested studiesCan use any of all 8 cases Dynamic Data Set (wind and no wind)Currently use summer peak, DWG proposal to use peak and off-peak case Stability Screening Studies (Dynamic and Voltage) PV and TS for summer, PV for winter peak and TS for winter off-peak NERC Compliance StudiesSummer peak and one off-peak

6. 6 Questions? ??? February 11, 2010