1. 1 Zero Charge Project Discussion COPS Bill Barnes 06/28/2005

2. 2 Agenda Zero Charge Process Review Zero Charge Metrics Costs Issues Options

3. 3 What is Zero Charge Process? Purpose: Logic and data to keep track of all settlement calculation output with total billable amount equal to zero per trade date, settlement run, and charge type. Grocery Store Receipt Analogy

4. 4 Zero Charge Process Review Settlement calculations result in either ZERO or NON- ZERO total billable amount for every charge type, settlement run, and trade date TD = 3/14/05Initial IntervalLIBILLAMT 150 2-75 3150 4-125 5 … 960 Total0

5. 5 Zero Charge Process Review Charges with ZERO total billable amount written to ZEROCHARGE and LSCH/LSCD (Interval Database) tables in Lodestar DB. –Every row in ZC table is associated with 5 rows in LSCH and LSCD for 5 settlement output determinants. Trade Date Settle Type LIPRICELIQTYLIAMTLIBILLQTYLIBILLA MT 3/14/05InitialIDB

6. 6 Zero Charge Process Review ZERO data flows to Market Participants through 1)Settlement Statement process and 2)Extract process. During these processes, large volumes of data are copied multiple times and carried across to multiple systems.

7. 7 Zero Charge Database Statistics (Production L* DB 4/26/05) TableTotal Row Count ZC Row Count Total Disk Space Total ZC Disk Space % Row Count % Disk Space Byte / Row ZERO- CHARGE 52,000,000 26 GB 100% 500 LSCH 398,500,000270,600,000224 GB146 GB 68% 65%562 LSCD 398,500,000270,600,000390 GB254 GB 68% 65%978

8. 8 ZC Growth TableZC Row Count Byte / RowTotal ZC Disk Space / day ZERO- CHARGE 80,000 500 40 MB LSCH 400,000 562 225 MB LSCD 400,000 978 391 MB

9. 9 Zero Charge Types 1) Every value in all cuts are zero. 2) Non-zero values sum to a total of zero. 3) BILLABLE AMOUNT = 0 for all intervals, but other cuts have non-zero values.

10. 10 ZC #1

11. 11 ZC #3 - Price

12. 12 ZC #3 - Quantity

13. 13 ZC Type Stats – Row Count All zero values (#1) Non-zero values (#2 and 3) 65%35%

14. 14 Zero Charge Database Statistics (Production L* DB 4/26/05) TableTotal ZC Disk Space Total ZC Disk Space / day % Disk Space – All Zeroes All Zeroes ONLY Total Disk Space All Zeroes ONLY Disk Space / day ZERO- CHARGE 26 GB 40 MB 64%17 GB 26 MB LSCH 146 GB 225 MB 64%93 GB 144 MB LSCD 254 GB 391 MB 64%163 GB 250 MB TOTAL 426 GB0.656 GB273 GB0.420 GB

15. 15 Cost Assume $80,000/TB ZC Type Disk Space P2 Prod P2 Lower Environ DBs Total P2 Disk Space Total P3 Disk Space Overall Total Disk Space Total Cost Disk Space / Day Cost / Day All Zeroes ONLY 273 GB154.1 TB $328k 6.3 GB$504 All ZC 426 GB156.4 TB $512k 9.8 GB$784

16. 16 Issues with Zero Charge Large Amount of Data oStorage  Database and File Server  Data duplication oMaintenance  Data propagation

17. 17 The Origin of Zero Charge Initial Settlement System Design –Provide Market Participants transparency into ERCOT Settlement calculations –Display all calculated settlement interval outputs regardless of value –Settlement calculation output provided in Settlement Statements and Settlement and Billing Extracts –Original Build The result is our existing design –Zero data calculated and stored

18. 18 ERCOT’s Options 1)Live with it 2)Market Approach –Stop producing Zero Charges on all settlement output with BILLAMT=0 –Stop producing Zero Charge on ALL ZEROES ONLY 3)System Redesign – Transparent to Market –Legal issue –Complexity

19. 19 Considerations What would be the impact to Market Participant Systems for #2? TNT effort?

20. 20 Questions