1 TSP Nodal Engagement Market Participant Call ERCOT August 04, 2010

General Reminders / Updates SSWG update NDSWG Update – None this week Agenda 2

Market Trials 2010 Roadmap 3

4 Full System Market and Reliability Testing Update

5 LFC Update –Next Full System Test 24-Hours in duration To start on Thursday 8/19/ :00 PM and complete on 8/20/ :00 PM Operational scenarios will be discussed on the Friday Real Time Market call –168-Hour update Additional discussions on the format and objectives were discussed at the NATF session on 8/9/2010 It was agreed that a revised Handbook would be published and discussed at a Special TAC session The special TAC session will occur on 8/12/2010

6 General Reminders

7 General Reminders –Joint NDSQG and NATF session to occur on Tuesday 8/17/2010 Session will be dedicated locking in modeling expectations Details are posted at: Reminder: Outage Scheduler with Zonal Outage Transfer Delete all Outages and run Zonal to Nodal Transfer Tool Friday, 8/13 (Note that 80% to 85% of the outages are transferred) Resource Outages will not be transferred by the Transfer tool The target is to make available for outage transfer validation and outage submissions Monday 8/16, 7:00 am, for the upcoming tests, optional months of October & November and for December and beyond A Market Notice will be sent out once ERCOT has completed this work. It is important that MPs do not start validation prior to receiving this Market Notice. Request list of Outages not transferred from Send to Market confirming outages have been validated by 9/17 for all Outages December and First production pull of OS data is scheduled for 10/2 for the first CRR Auction TSPs and QSEs are responsible to ensure that the outages in the Nodal Outage Scheduler are correct Outages previously approved in zonal will be automatically approved in Nodal

ERCOT TAC Meeting - ROS Report 03/04/2010 Ken Donohoo 8 Nodal Model Effort Activity Operations Model (NMMS) CRR Model Topology Processor (Software) Long Term Planning Model NDSWG Support SSWG Support SSWG Support SSWG & ERCOT Development

SSWG Planning Model Activities Correcting Connectivity Node Groups –Aug 6 TP output: 87 CNGs needing correction Phase II Corrections: Area #, Zone #, Load ID, Branch ID, Generator ID, mileage –ERCOT sent correction spreadsheet July 9 –Due July 30 August 15 Deadline for submitting NOMCRs to correct planning data

SSWG Planning Model Activities New Topology Processor update delivered to ERCOT –Being tested by ERCOT and SSWG –SSWG has submitted a System Change Request (SCR759) related to the Topology Processor changes ROS approved with “High” priority at July 15 meeting ROS to formally approve and place in Priority List at Aug 13 meeting Identifying important modeling issues –Categorize these and determine if additional SCRs are necessary –SSWG to work on drafting next SCR MOD/PMCR Training complete –MOD Sandbox to be opened for TSP access until Sept 1 Aug 18 meeting –Plan 2010 Test Case procedure –First test of creating case with new method –Many unknowns to be discussed

SSWG Modeling Issues Annual Planning Model related issues: SPS: Additional equipment modeled in IMM Off-nominal transformers: TP not calculating impedances correctly Transformer modeling: 2 winding vs 3 winding No ratings on zero impedance line segments Ownership Loads and cap banks being collapsed to the correct CNGs Cap banks connected to distribution voltage FACTS devices Future versions of PSSE MOD issues: submission process, access, project types, user- defined fields, PMCR to NOMCR transition TSPs without PSSE or MOD File Builder

SSWG Nodal Schedule June – AugustMake remaining changes to IMM prior to Planning Go-Live July TSPs Complete changes based on TP enhancements Aug 15Deadline for submitting NOMCRs with planning changes Aug 18SSWG 2010 test case meeting AugCompare TP output to SSWG 2010 summer peak case NovCreate 2012 summer peak case using TP and MOD Dec – Feb 2011Review, update, and modify TP/MOD process for case creation Dec 1Nodal Go-Live Mar – April 2011Assuming Nov test meets SSWG approval, begin work to create 12DSA using Nodal method

Telemetry Quality Update July SE Telemetry Standards Report Posted on MIS Secure –Monthly and Quarterly Telemetry Point Availability Statistics Report (June and July 2010) –Quarterly Point Availability Statistics Report (Q2 2010) –Reports => Reports and Extracts Index TSPs –11 out of 20 TSPs above 98% for June, No TSPs below 90% –18 out of 20 TSPs above 98% for July, No TSPs below 96% QSEs –58 out of 79 QSEs above 98% for July % average for the 21 QSEs below 98% 13

Telemetry Quality Update MP23 Telemetry Quality Metric –Needed for Nodal Readiness. Scheduled to light up 8/25 (using July 2010 statistics) –ERCOT will use the 98% threshold. If the Telemetry Standards are modified and approved by TAC, ERCOT will adopt the new threshold in the metric. –Will be updated monthly until Nodal Go-Live (based on monthly statistics) –From 8/25 to 9/30 Green >= 98%, Amber >= 90% and < 98%, Red < 90% –From 10/1 – Nodal Go-Live Green >= 98% Red < 90% –For new equipment and outages, TSPs and QSEs can manually override telemetry to ensure that availability statistics are as accurate as possible Communication –For any concerns over reports, contact –For resolution to telemetry issues, contact 14