01/17/ CP Discussion October 16,2002 Retail Market Subcommittee Austin, Texas

2 Protocol References 9.8 Transmission Billing Determinant Calculation ERCOT will provide the market with the determinants defined below to facilitate billing of Transmission access service. ERCOT will not be responsible for billing, collection or dispersal of payments associated to Transmission access service ERCOT shall calculate and provide to Market Participants via MIS the following data elements annually to be used by TDSP’s as billing determinants for Transmission access service. This data shall be provided by December 01 of each year. This calculation shall be made in accordance with the requirements of the PUCT. The data used to perform these calculations shall come from the same system(s) used to calculate settlement-billing determinants used by ERCOT: 1. The 4-Coincident Peaks (4-CP) for each TDSP, as applicable. 2. The ERCOT average 4-CP. 3. The average 4-CP for each TDSP, as applicable, coincident to the ERCOT average 4-CP. Average 4-CP is defined as “the average Settlement Interval coincidental MW peak occurring during the months of June, July, August, and September.” Settlement Interval MW coincidental peak is defined as “the highest monthly 15 minute MW peak for the entire ERCOT Transmission Grid as captured by the ERCOT settlement system.”

3 Data Aggregation Process

4 Quantity Conversion & Sum by TDSP For each load cut, there are 96 interval of MWH data Unique combinations of LSEGUFE for the 4CP trade dates 949 in August 1,121 in September Quantity Conversion consists of converting the MWH data into KW KW = MWH X 4 X 1000 LSEGUFE Load Cuts are Summed by TDSP for the peak interval. Note: Cuts where the Lodestar LSE Code equals a DC Tie name were omitted from the TDSP totals.

5 Data Cut Definitions Load Segment Cut Type: LSEGUNADJ = Base Load values LSEGDL = Base Load + Distribution Losses LSEGTL = Base Load + Distribution Losses +Transmission Losses LSEGUFE = Base Load + DL + TL + UFE Lodestar LSE Code: ( 1 = RELIANT LSE) Lodestar QSE Code: (14 = RELIANT) Load Profile Code: Distribution Loss Factor Code (A-E or T) UFE Settlement Zone Congestion Management Zone Lodestar TDSP Code: (1 = RELIANT)

6 Lodestar TDSP to 4 CP Entity Mapping 126 Unique TDSPs in Lodestar 77 Load Entities in 4 CP Submission s 77 Load Entities in 4 CP Submission s Versus Lodestar TDSPs are mapped to the corresponding 4-CP Load Entity Listing. KW Per Lodestar TDSP is summed per mapping. Complete mapping list is included in ERCOT filing with PUC

7 Process Summary Select Peak Interval and Convert MWH to KW Sum KW per Lodestar TDSP (Omitting DC Ties) Sum Lodestar TDSPs to 4CP Entity List Compile 4 Months data into Average 4CP for PUC Filing Determine Time of Peak for each 4 CP Month Secure Aggregation Load Cut Data for 4 CP Trade Days

8 UFE Data MWH 1,732,080 KW August 16: MWH 1,659,400 KW September 7 16:30 Energy is allocated to load cuts in competitive TDSP service areas based upon UFE allocation mechanism in Section 11 of Protocols.

9 What’s New with the Resettlement Data? Less Estimation 100% of IDR Data was Present 99+% or Non-IDR Data was Present Data Modifications Corrections to NOIE Wholesale Points Removal of ESI IDs created in error Removal of Substation ESI IDs Correction to Generation Site Data New Peak Day Revealed for August New Peak is August 15 4:30 PM (Previous August peak was August 22 4:45 PM)

10 Comparison of August Data (March ’02 data VS October ’02 Data) 0.0% Change For The Remaining 70 Entities

11 Comparison of Sept 7 th Data (March ’02 data VS October ’02 Data) 0.0% Change For The Remaining 72 Entities

12 Comparison of March ‘02 Filing to October ‘02 Filing 0.0% Change For The Remaining 72 Entities

13 Transmission Connected IDR Information

14 Questions