1 1 TPTF Review of Nodal Program Schedule Readiness to Send Schedule to TAC January 13, 2009

2 2 Discussion Topics Six Major Market Participant-Identified Schedule Issues TPTF Readiness to send Nodal Schedule to TAC

3 3 Outstanding Significant MP Schedule Issues Transmission Asset Registration Single Entry Model (NMMS Tool) Go Live MP Connectivity Testing & Requalification NMMS for Planning Models Commercial Operations Market Trials Outage Schedule Market Trials

4 4 Transmission Asset Registration Feedback received from TPTF The Transmission Asset Registration activities have already been performed; MPs should not be required to re-verify transmission asset information Background and Rationale for Transmission Asset Registration ERCOT has received a large quantity of data from the Market, but still needs to establish a verified inventory of resource and transmission assets In order to achieve this ERCOT requires RE’s verification of any data submitted to ERCOT once it is integrated into the Nodal model (and in some cases integrated to the Nodal RARF) History of Registration Activities 10/2007 – ERCOT engages market with Nodal RARF 10/2007 – ERCOT engages market in the first part of MP10 (mapping of resource nodes and EPS meters to resources) 08/2008 – ERCOT engages market with a process to complete the RARF components (in order of priority to nodal critical path): Resource Registration (Completed 12/08) Transmission Asset Registration (moved to 2009 in order to lock step w/ final MP10 validation after SEM go live) Planning / Protection Data (2009)

5 5 Transmission Asset Registration (cont’d) Resolution ERCOT is developing an audit report process which mirrors the Resource Data Audit Process ERCOT will ensure that all previously submitted Nodal Transmission Data is overlaid on existing zonal data (this guarantees maximum coverage of previously submitted data) ERCOT will run the audit report process and provide RE’s an audit report, current RARF and one lines for each of their sites Resource Entities will need to correct business rule errors and perform final verification that ERCOT has captured previously submitted data correctly Overview To date, many Resource Entities have submitted transmission data via the following artifacts: RARF – Transmission Assets Tab and GSU Transformer Tab MP10 – corrected / modified one lines via TDF form The Objective for 2009 is to achieve the same level of Transmission and Planning / Protection data quality as the Resource data achieved in 2008 Current gaps to this objective are: Transmission and Planning / Protection Data have not been vetted against any business rules Resource Entities have not performed final verification of the Transmission Data and Nodal one lines

6 6 Single Entry Model (NMMS Tool) Go-Live Issues Resolution A detailed discussion on SEM Go-Live schedule, TSP training, TSP testing, additional validation activities and documentation will be held during the NDSWG meeting on Jan 20, All TSPs are requested to attend the meeting ERCOT is currently drafting the NMMS Validation Rules document and will publish it by Jan 31, 2009 Feedback received from TPTF Provide additional information on details ERCOT and MP validation activities Ensure schedule includes release of all SEM-related documentation (validation rules, modeling guidelines, Stage I Data Consistency) Engage TSPs in SEM-related activities

7 7 MP Connectivity Testing & Re-Qualification Resolution Delivery of a status for section 3 through section 12 of the EIP – External Interfaces Specification document EIP specs will be discussed as part of the EDS 3 Market Call on Jan 30 or Feb 6, which is conducted every Friday, 9:30am ( decision on which meeting this status will be provided during will be communicated prior to the meeting Status will be based on v1.17 but will include sections updates as they related to v1.18 or v1.19 Approach allows MPs to begin coding to certain sections of the specification, if desired ·EIP – External Interfaces Specification v1.19 is targeted to be the “final” version (“final” defined as containing a complete set of inbound and outbound market interaction specifications; will be subject to defect fixes) Specification delivery targeted for early June 2009 Delivery to the sandbox will be one month later (early July 2009) Delivery to a market facing environment will be one month later (early August 2009) Allows MPs four months of testing time from delivery of “final” spec until beginning of MP connectivity testing Details of engagement timeline on next slide Feedback received from TPTF Market Participants expressed concern with timing of the release of EIP specifications and availability of testing platforms to prior to qualification testing Concern there is not enough time between qualification activities and readiness for posting LMPs Concern there is not alignment of transitioning from FIT to integrated SCED/LFC activities Ambiguity of when the market needs to be fully engaged and testing

8 8 MP Connectivity Testing & Re-Qualification (cont’d) Market facing MMS5/EIP v1.19 and MMS UI MarAprMayJunJulAugSepOctNovDecJanFeb Publish EIS V1.19 Sandbox EIS FIT Ext Interface Spec FIT testing for Telemetry only FIT testing for Tel and SCED begins All QSE w/Resources Qualified DAM submission qualification All QSEs qualified Open Loop test 1 LFC Individual QSE begins Key EDS milestone DAM exec begins 6 Mth LMPs ….. EDS release EIS V MMS + UI Sandbox QSE dev & testing SCED Qual LMP posting begins

9 9 NMMS for Planning Models Feedback received from TPTF The task of building Transmission Planning cases using NMMS should be removed from the Nodal Go-live schedule to avoid unnecessary risks of delay and cost-overruns. Using NMMS to construct planning cases is highly complex, has not been achieved in any NERC region, isn’t required to implement nodal and therefore should be rescheduled as an optional post go-live activity. Background and rationale for using NMMS for Planning Models Nodal Protocols Section and mandate ERCOT to ensure consistency between the Network Operations model, the Annual Planning Model and the CRR Network Model NMMS enables ERCOT to ensure consistency between Network Operations Model, Annual Planning Model and the CRR Network Model by serving as the system of record for all three models. Planning Models will be generated through NMMS by using the Network Operations Model as the source of model data CRR group uses NMMS as the source of model data and as a source for Planning Model Change Requests (PMCRs) submitted by TSPs into NMMS, to generate CRR network model

10 NMMS for Planning Models (cont’d) Resolution ERCOT will hold a Steady State Working Group (SSWG) meeting in Feb 2009 to discuss ERCOT and TSP activities that need to be performed for transition of NMMS for Planning Model Management. ERCOT is currently drafting the Planning Model Go-Live Procedure and will present a draft of the document at the SSWG in Feb 2009 The Planning Model go-live procedure will be published for TSP comments, before seeking SSWG and ROS endorsement Changes to business process, technical software, and interfaces will adversely impact proposed Nodal Go-Live date and therefore is not an option Potential impact if NMMS is not used for Planning Model Management Ensuring consistency between Network Operations Model, Annual Planning Model and the CRR Network Model could be challenging and further impact analysis will have to be performed The Planning services group at ERCOT has been staffed assuming NMMS will be the tool to manage Annual Planning Models Similarly, the CRR group’s procedures and resource planning assumes availability of NMMS for generating CRR models and for PMCR information. Any change could impact execution of CRR annual auctions

11 Commercial Operations Market Trials Resolution ERCOT evaluating feasibility of posting Stmt/invoices/Extracts sooner. Recommend a phased validation approach to be presented at February TPTF Approach would focus on validation of certain determinants and other criteria, be performed in staggered timeframe, and described in the handbook in detail (as done historically) Approach still complies with 6-months of settlement testing requested by MPs History of COMS Activities April/May 2008 ( –Draft Settlement Statements and Invoices Statements and Invoices created for LCRA and posted Focus on formats No backup settlement data provided Referred to as “Standard” on EDS 4 Release 8 Postings matrix –Mock Statements and Invoices - Made Up Data Fictitious data created for 13 Market Participants and posted for all – labor intensive Supporting data provided in files (not in Extract format) Referred to as “Mock” on EDS 4 Release 8 Postings matrix –Mock Statements and Invoices – MMS DAM Output DAM settlement run for 4 Operating Days Input data included MMS DAM output and stubbed data Not fully integrated - data required a lot of massaging Limited Charge Types Referred to as “Mock” on EDS 4 Release 8 Postings matrix Feedback received from TPTF S&B Posting activities start too late in EDS DAM begins 2/15/10 First DAM Stmt/Invoices 3/15/10 First Real-Time Stmt/Invoices 4/15/10 Market request to start posting sooner after Feb activities begin

12 Commercial Operations Market Trials – Cont’d Feedback received from TPTF Extracts activities start too late in EDS, more program support (such as samples or test data) are needed in 2009 Resolution 08/2008 DEWG noted action item to follow up on the possibility of generating sample data extracts from DDLs. ERCOT will reach out to DEWG for reopening up the discussion for this effort as well as training with published information Program has worked with DEWG for Extract Delivery Plan Draft DDL and XSDs that provide the structure of extracts published Dec 07 …very few changes The User Guides and DDL detail comments are in development and targeted to be published by March This information provides additional business field data definitions (ie: time in CST/CPT/GMT, uidchannel value for Final, True-Up, and Resettlements, etc.)** Approach has been satisfactory solution in zonal for new and updated extracts If ERCOT can publish sample/test extracts with system generated data from their test environment sooner, they will. Mar 2010 was based on the Integration test completion and EDS start schedules. ***Still complies with 6- month Settlement testing as requested by MPs.

13 Outage Scheduler Market Trials Resolution The approved Nodal Go-Live procedure requires QSEs with Resources and TSPs to conduct dual-entry of outages into both Zonal and Nodal Outage Scheduler systems for up to 45 days during the 168-Hour Test and leading up to Nodal Go-Live Alternative scenarios to enable single entry of outages by QSEs and TSPs were considered by ERCOT and deemed to not be viable because they would introduce additional hardware and/or software changes Feedback received from TPTF TPTF requested ERCOT to provide options for single entry of Outages

14 Readiness to Send Nodal Program to TAC Open Discussion Next Steps

15 Review of TPTF Nodal Schedule Action Item TPTF meeting on Monday (1/12/09) reviewed all received comments and reflected current disposition Excel spreadsheet that was distributed to TPTF on 1/14/09 includes –Comments collected from market participants during 12/10/08, 1/7/09, 1/12/09, and 1/14/09 TPTF meetings, as well as submitted via –Open/Closed status is as of COB 1/12/09 and discussed at TPTF on Monday 1/12/09 –New status reflects comments received between 1/12/09 and 1/14/09 Purpose of review is to ensure all comments are documented –ERCOT is not prepared to take any additional action on any action items ERCOT is preparing a Market Participant milestone view that reflects all closed action items that were schedule related later and will be distributed to TPTF later today