UFE 2004 ANALYSIS

1. UFE 2004 ANALYSIS Compiled by Load Profiling ERCOT Energy Analysis & Aggregation

2. Sources of UFE include: ■ Generation Measurement Errors ■ Load - Missing/Erroneous Usage Data - Model Error - Load Profile ID Assignment Error ■ Losses - Model Error - Loss Code Assignment Error UFE Basics • UFE (unaccounted for energy) is computed as follows: UFE = Generation – (Load + Losses) • Negative UFE indicates load/losses are overestimated

3. UFE GAP - - - - - - > Losses: Transmission & Distribution Profiled Energy Usage Non-Interval Data Non-Metered Accounts Interval Data Energy Usage UFE Basics Net Generation forSettlement Interval Net Generation Compared to Load Buildup

4. Final Settlement Initial True-Up DATA VERIFICATION IN THE SETTLEMENT PROCESS UFE is computed for each 15-minute interval of a settlement run. • Initial Settlement(posted on day 10 after the operating day) • Final Settlement (posted on day 60 after the operating day) • True-up Settlement (posted 6 months after operating day) • Resettlement statement (posted as needed)

5. Load Weighted Calculation of MCPE • Market Clearing Price for Energy (MCPE) isthe highest price by Congestion Zone for a Settlement Interval for Balancing Energy deployed during the Settlement Interval. • In 2004 there were 5 congestion zones – E04, H04, N04, S04 and W04. • The load weighted MCPE is calculated for each 15 min. interval using the LCMZone cuts as follows: MCPE_LWTD = ((LCMZone_E04_Mwh * MCPEL_E04) + (LCMZone_H04_Mwh * MCPEL_H04) + (LCMZone_N04_Mwh * MCPEL_N04) + (LCMZone_S04_Mwh * MCPEL_S04) + (LCMZone_W04_Mwh * MCPEL_W04)) / (LCMZone_E04_Mwh + LCMZone_H04_Mwh + LCMZone_N04_Mwh + LCMZone_S04_Mwh + LCMZone_W04_Mwh)

6. LOAD AND UFE – ERCOT PEAK 2004Initial Settlement SR01

7. LOAD AND UFE – ERCOT PEAK 2004Final Settlement SR02

8. LOAD AND UFE – ERCOT PEAK 2004True Up Settlement SR03

9. UFE MWh by Month Initial Settlement SR04

10. UFE Cost by Month Initial Settlement SR05

11. UFE MWh by Month Final Settlement SR06

12. UFE Cost by Month Final Settlement SR07

13. UFE MWh by Month True-Up Settlement SR08

14. UFE Cost by Month True-UP Settlement SR09

15. ABS UFE Mwh by Month Initial, Final and True Up Settlements SR09a

16. UFE Cost by Month Initial, Final and True-UP Settlements SR09b

17. STATISTICAL SUMMARY - 2004 SR10

18. STATISTICAL SUMMARY - 2004 SR11a

19. STATISTICAL SUMMARY - 2004 SR11b

20. STATISTICAL SUMMARY - 2004 SR12a

21. STATISTICAL SUMMARY - 2004 SR12b

22. STATISTICAL SUMMARY - 2004 SR13a

23. STATISTICAL SUMMARY - 2004 SR13b

24. STATISTICAL SUMMARY - 2004 SR14a

25. STATISTICAL SUMMARY - 2004 SR14b

26. STATISTICAL SUMMARY – MONTHLY for 2004 SR15

27. STATISTICAL SUMMARY – MONTHLY for 2004 SR16

28. STATISTICAL SUMMARY – MONTHLY for 2004 SR17

29. STATISTICAL SUMMARY – MONTHLY for 2004 SR18

30. STATISTICAL SUMMARY – MONTHLY for 2004 SR19

31. STATISTICAL SUMMARY – MONTHLY for 2004 SR20

32. STATISTICAL SUMMARY – MONTHLY for 2004 SR21

33. STATISTICAL SUMMARY – MONTHLY for 2004 SR22

34. STATISTICAL SUMMARY – MONTHLY for 2004 SR23

35. STATISTICAL SUMMARY – MONTHLY for 2004 SR24

36. STATISTICAL SUMMARY – MONTHLY for 2004 SR25

37. STATISTICAL SUMMARY – MONTHLY for 2004 SR26

38. STATISTICAL SUMMARY – MONTHLY for 2004 SR27

39. STATISTICAL SUMMARY – MONTHLY for 2004 SR28

40. STATISTICAL SUMMARY – MONTHLY for 2004 SR29

41. STATISTICAL SUMMARY – MONTHLY for 2004 SR30

42. STATISTICAL SUMMARY – MONTHLY for 2004 SR31

43. STATISTICAL SUMMARY – MONTHLY for 2004 SR32

44. Percent Distribution of Total UFE (MW) Initial to Final - 2004 UFD01

45. Percent Distribution of Total UFE (MW) Final to True-Up - 2004 UFD02

46. 2004 Distribution of UFE Percent of ERCOT Load UFD03

47. UFE Percent of ERCOT Load – Initial Settlement 95% Confidence Interval CIP01

48. UFE Percent of ERCOT Load – Final Settlement 95% Confidence Interval CIP02

49. UFE Percent of ERCOT Load – True-Up 95% Confidence Interval CIP03

50. Comparison of Medians With 95% Confidence Interval CIP04