UFE 2007 ANALYSIS

1. UFE 2007 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 - Theft ■ 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 OVERVIEW OF 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 2007 there were 4 congestion zones – H07, N07, S07 and W07. • The load weighted MCPE is calculated for each 15 min. interval using the LCMZone cuts as follows: MCPE_LWTD = ((LCMZone_H07_MWh * MCPEL_H07) + (LCMZone_N07_MWh * MCPEL_N07) + (LCMZone_S07_MWh * MCPEL_S07) + (LCMZone_W07_MWh * MCPEL_W07)) / (LCMZone_H07_MWh + LCMZone_N07_MWh + LCMZone_S07_MWh + LCMZone_W07_MWh)

6. LOAD AND UFE – ERCOT PEAK 2007Initial Settlement SR01

7. LOAD AND UFE – ERCOT PEAK 2007Final Settlement SR02

8. LOAD AND UFE – ERCOT PEAK 2007True Up Settlement SR03

9. UFE MWh by Month in 2007Initial Settlement SR04

10. UFE Cost by Month in 2007 Initial Settlement SR05

11. UFE MWh by Month in 2007Final Settlement SR06

12. UFE Cost by Month in 2007 Final Settlement SR07

13. UFE MWh by Month in 2007 True-Up Settlement SR08

14. UFE Cost by Month in 2007 True-UP Settlement SR09

15. ABS UFE MWh by Month in 2007 Initial, Final and True Up Settlements SR09a

16. ABS UFE Cost by Month in 2007 Initial, Final and True-Up Settlements SR09b

17. STATISTICAL SUMMARY - 2007 SR10

18. STATISTICAL SUMMARY - 2007 SR11a

19. STATISTICAL SUMMARY - 2007 SR11b

20. STATISTICAL SUMMARY - 2007 SR12a

21. STATISTICAL SUMMARY - 2007 SR12b

22. STATISTICAL SUMMARY - 2007 SR13a

23. STATISTICAL SUMMARY - 2007 SR13b

24. STATISTICAL SUMMARY - 2007 SR14a

25. STATISTICAL SUMMARY - 2007 SR14b

26. STATISTICAL SUMMARY – MONTHLY for 2007 SR15

27. STATISTICAL SUMMARY – MONTHLY for 2007 SR16

28. STATISTICAL SUMMARY – MONTHLY for 2007 SR17

29. STATISTICAL SUMMARY – MONTHLY for 2007 SR18

30. STATISTICAL SUMMARY – MONTHLY for 2007 SR19

31. STATISTICAL SUMMARY – MONTHLY for 2007 SR20

32. STATISTICAL SUMMARY – MONTHLY for 2007 SR21

33. STATISTICAL SUMMARY – MONTHLY for 2007 SR22

34. STATISTICAL SUMMARY – MONTHLY for 2007 SR23

35. STATISTICAL SUMMARY – MONTHLY for 2007 SR24

36. STATISTICAL SUMMARY – MONTHLY for 2007 SR25

37. STATISTICAL SUMMARY – MONTHLY for 2007 SR26

38. STATISTICAL SUMMARY – MONTHLY for 2007 SR27

39. STATISTICAL SUMMARY – MONTHLY for 2007 SR28

40. STATISTICAL SUMMARY – MONTHLY for 2007 SR29

41. STATISTICAL SUMMARY – MONTHLY for 2007 SR30

42. STATISTICAL SUMMARY – MONTHLY for 2007 SR31

43. STATISTICAL SUMMARY – MONTHLY for 2007 SR32

44. Distribution of UFE MW Initial, Final, and True Up - 2007 UFD01

45. 2007 Distribution of UFE as Percent of ERCOT Load UFD03

46. Distribution of UFE MW 2006 vs. 2007 - Initial Settlement UFD04

47. Distribution of UFE MW 2006 vs. 2007 - Final Settlement UFD05

48. Distribution of UFE MW 2006 vs. 2007 – True Up Settlement UFD06

49. Distribution of UFE Percent of ERCOT Load 2006 vs 2007 – Initial Settlement UFD07

50. Distribution of UFE Percent of ERCOT Load 2006 vs 2007 – Final Settlement UFD08