1. Texas Nodal March 20061 Texas Nodal NMMS Requirements By John Adams ERCOT

2. Texas Nodal March 20062 Agenda Overview of NMMS Requirement Comments (Buckets) Creation of Nodal Model Forum Where are we on the NMMS requirements timeline Does Texas Nodal require the proposed NMMS? Other NMMS implementations Nodal Modeling from a transmission planning view NMMS Requirements Q&A

3. Texas Nodal March 20063 Overview of NMMS Requirement Comments Category of Comment/resolution KeyNumber of submittals Proposed Change to document/ accepted CG115 Comment received but no change to document CM58 Question or Comment which is a detailed design question DD44 Comment which seems to require nodal protocol change PI2 Outside scope of NMMSSC1

4. Texas Nodal March 20064 Overview of NMMS Requirement Comments NMMS is not a pre-requisite to Nodal Transmission Network modeling difficult, and needs to be carefully coordinated with the transmission provider involved; A central database which builds power flow cases is an inherently risky undertaking which has a high risk of building cases which will not converge. The proposed NMMS processes make planning more difficult for ERCOT TDSP’s. More detail describing requirements is desired Specific technical requirements should be added

5. Texas Nodal March 20065 Creation of a Nodal Modeling Forum TPTF focus is on nodal protocol compliance TPTF Planning Principle: “ERCOT shall develop a process to identify areas where the design contemplated by the protocols is not feasible, cost effective, or the most effective” To address the above TPTF planning principle ERCOT proposes the creation of a Nodal Modeling Forum

6. Texas Nodal March 20066 Where are we on the TPTF Systems Specification, Procurement and Development Track? Nodal Protocols System Conceptual Design Document Detailed Design Engage NMF team to address feasibility, cost and effectiveness Engage NMMS Vendor Business Requirements TPTF Approval TPTF Approval TPTF Comment ERCOT is positioned to engage a NMMS vendor and will utilize the drafted NMMS Business Requirements. The ERCOT Nodal Transition Plan requires TPTF to approve the Business Requirements document as being in compliance with protocols before they are used. ERCOT envisions a collaborative effort between the NMMS Vendor, Market Participants (via NMF) and ERCOT staff in the development of the System Conceptual Design Document. NMMS feasibility, cost and effectiveness issues can be addressed during the development of the System Conceptual Design Document.

7. Texas Nodal March 20067 Does Texas Nodal require the proposed NMMS? 1.To meet requirement for a model that contains all changes over a period of time and the changes can be implemented in the model as they are scheduled (Timeline). 2. To meet requirements for data consistency between Network Operations, Annual Planning, and CRR models

8. Texas Nodal March 20068 Timeline Options: a)CIM incremental Model updates. b)Pseudo switches. We selected CIM incremental Model updates. Using pseudo switches in the model is very labor intensive and error prone. Other users are seeking methods to move away from pseudo switch usage.

9. Texas Nodal March 20069 Consistency Options: a)Common database structure b)Manual comparisons We selected common Database structure We presently do manual comparisons and they are very manpower intensive.

10. Texas Nodal March 200610 What is going on in the modeling arena Others interested in CIM based modeling software: –WECC has RFP out for CPSM (NERC CIM based Common Power System Model) –MISO has RFP out to combine Operations and Planning database –Transpower (New Zealand) has purchased Nodal software including CIM based package combining Planning and Operations database –Transmission System Modeling Builder (TSMB) Project by EPRI

11. Texas Nodal March 200611 Nodal Modeling from a transmission planning view –Data & effort similar NowWith NMMS Load data provided via Annual Load Data Request (ALDR) process Same Generation Data gathered via Generation Interconnection or Change Request process and via asset registration Same Detailed transmission project data and timing is provided via the (TPIT) workbook Updated on a quarterly basis Detailed project data and timing provided via NMMS interface. Updated as available. ROS SSWG currently produces eight seasonal next year cases (Data Set A) and six future year cases (Data Set B)Updated on an annual and quarterly basis Same? ROS DWG produces flat start cases annuallySame ROS SPWG produces short circuit cases annually Same Consistency and application of data is ongoingSame TCR process builds cases and assesses expected additional transfer capability across CSC interfaces. CRR process builds at least 12 monthly cases looking 12 months ahead and assesses point- point capability

12. Texas Nodal March 200612 NMMS Requirements Q&A