Texas Nodal Commercial Systems COMS CSD Presentation By ERCOT Wednesday, 1/10/2007

1. Texas NodalCommercial SystemsCOMS CSD PresentationBy ERCOTWednesday, 1/10/2007 1 Texas Nodal

2. Agenda • Commercial System Solution • Commercial Systems (COMS) Coverage • High Level CSD Process • Example Dependency Maps • Outstanding Needs • Summary 2 Texas Nodal

3. Commercial System Solutions • For all Commercial System Solutions with the exception of Credit Monitoring and Management (CMM), the solution will be built by customizing existing software to meet ERCOT Nodal Protocols. • LODESTAR will be used for • Settlements and Billing • Data Aggregation • Financial Transfer • Statements and Invoices • Siebel will be used for • Registration • Disputes • Additional Visual Basic apps will be built as needed to supplement the LODESTAR and Siebel solutions • CMM will purchase a COTS product from ROME and customize the implementation to meet ERCOT Nodal protocols 3 Texas Nodal

4. Commercial Systems Coverage • 11 Commercial System CSDs cover the associated TPTF approved Requirements • Day Ahead Market CSD • Day-Ahead Market Energy Settlements Requirements, including Settlements for PTP Obligations Bought in DAM • Day-Ahead Congestion Rent Requirements • Day-Ahead Make-Whole Settlements Requirements • Day-Ahead Market Ancillary Service Settlements Requirements • Real-Time Settlement CSD • Ancillary Services Real-Time Settlements Requirements • Real-Time Energy Settlements Requirements • Black Start Services Real-Time Settlements Requirements • Real-Time Emergency Operations Settlements Requirements • Reliability Must Run Services Real-Time Settlements Requirements • Voltage Support Real-Time Settlements Requirements • RUC Settlement CSD • Reliability Unit Commitment (RUC) Settlements Requirements • Verifiable Cost Settlement Requirements 4 Texas Nodal

5. Commercial Systems Coverage (cont) • Congestion Revenue Rights CSD • Day-Ahead Market Congestion Revenue Rights Requirements • Real-Time Congestion Revenue Rights Requirements • Congestion Revenue Rights Balancing Account Requirements • Congestion Revenue Rights Auction Revenue Disbursement Requirements • Eligibility Process Settlements CSD • Eligibility Process for Settlements Requirements • Average Incremental Energy Cost CSD • Average Incremental Energy Cost (AIEC) Settlement Requirements • Statements and Invoices CSD • Statement Requirements • Invoice Requirements • Financial Transfer CSD • Financial Transfer Requirements • Data Aggregation CSD • Data Aggregation Requirements • Registration System CSD • Registration System Requirements (not approved) 5 Texas Nodal

6. High Level Commercial Systems CSD Process Summary • All CSD documents follow the same conventional style as listed below: • Function: is the beginning of the section • Introduction: is a brief description of the section and related calculations • Inputs: Data elements, or processes required for section • Processing: High level summary of process description • Outputs: output parameters, data, processes, or resultant set 6 Texas Nodal

7. Requirements to CSD relationship • Dependency charts provided in the requirements documents were used to generate process flow diagrams • All examples in presentation are listed in CSD documents along with many additional graphical representations. • Additional clarifications during detailed design will flesh out the automated and manual processes and procedures 7 Texas Nodal

8. Day Ahead Example 8 Texas Nodal

9. Real Time Example 9 Texas Nodal

10. RUC Example 10 Texas Nodal

11. CRR Settlement Examples CRR Day Ahead and Real time CRR Balancing Account 11 Texas Nodal

12. AIEC Example 12 Texas Nodal

13. Eligibility Example 13 Texas Nodal

14. Statements and Invoices Example 14 Texas Nodal

15. Financial Transfer Example 15 Texas Nodal

16. Outstanding Needs and Next Steps • Need to clarify database footprint within Detailed Design • Need to finalize Software solution (Version of LODESTAR and patches) • Need to solidify timing and data elements of integration points from other Nodal Systems during Detailed Design • Need to determine disposition of all Commercial Systems CSD punchlist items by TPTF. This could produce additional NPRRs and/or changes to requirements • Examples include for RUC: • Change references of RUCDECOMMIT to be RUCD • Incorporate RUCSUFLAG changes into RUCG calculations • Remove LARUCAMTQSETOT, LARUCCBAMTQSETOT, LARUCDCAMTQSETOT • Add RUCD as driver for VERISU and VERIME • Incorporate changes from Eligibility Process into RUCDCAMT calculations • Examples include for Eligibility: • Add SELFCOMMITFLAG determinant and QSE Self-Commitment calculations • Remove stipulation in RUC De-commitment calculations that sets all non de-committed hours to 0 in the SUFLAG determinant will need to be removed. • This may also necessitate an NPRR 16 Texas Nodal

17. Summary • All CSDs are intended to cover their respective Requirements as approved by TPTF and associated protocols • All Commercial Systems CSD comments are due back to ERCOT on January 18th, 2007 17 Texas Nodal