ERCOT Staff Load Factor Review PWG Presentation

February 23, 2005

2

Criteria Used for Business Load Factor (LF) Analysis

• ESI IDs were grouped by their current profile in ERCOT.• BusLoLF• BusMedLF• BusHiLF

• May through April Annual Validation windows for 2002, 2003, and 2004 were used to calculate assignments for each respective year.

• Load Factors were calculated from usage loaded at ERCOT.

• ESI IDs were chosen if they had a Load Factors for all 3 years.

• ESI IDs were excluded if their Load Factors was > 1 in any of the 3 years.

• ESI IDs were excluded if their ’04 Load Factors did not match their current profile. (<1% effected)

3

2004 Business High Load Factor Review

Calculated Calculated CalculatedProfile Profile Profile % of2002 2003 2004 Total

BUSHILF BUSHILF BUSHILF 14,825 65.73%BUSMEDL BUSHILF BUSHILF 2,855 12.66%BUSMEDL BUSMEDL BUSHILF 2,695 11.95%BUSHILF BUSMEDL BUSHILF 1,255 5.56%BUSLOLF BUSMEDL BUSHILF 286 1.27%BUSLOLF BUSLOLF BUSHILF 270 1.20%BUSLOLF BUSHILF BUSHILF 215 0.95%BUSMEDL BUSLOLF BUSHILF 104 0.46%BUSHILF BUSLOLF BUSHILF 50 0.22%

22,555 100%

Profile Segment Tracking of 2004 Business High Load Factor

2002 through 2004

Count

4

2004 Business Medium Load Factor Review

Calculated Calculated CalculatedProfile Profile Profile % of2002 2003 2004 Total

BUSMEDL BUSMEDL BUSMEDL 43,665 67.28%BUSLOLF BUSMEDL BUSMEDL 6,121 9.43%BUSLOLF BUSLOLF BUSMEDL 5,709 8.80%BUSMEDL BUSLOLF BUSMEDL 2,683 4.13%BUSHILF BUSMEDL BUSMEDL 2,394 3.69%BUSHILF BUSHILF BUSMEDL 2,185 3.37%

BUSMEDL BUSHILF BUSMEDL 1,873 2.89%BUSLOLF BUSHILF BUSMEDL 144 0.22%BUSHILF BUSLOLF BUSMEDL 128 0.20%

64,902 100%

of 2004 Business Medium Load Factor2002 through 2004

Count

Profile Segment Tracking

5

2004 Business Low Load Factor Review

Calculated Calculated CalculatedProfile Profile Profile % of2002 2003 2004 Total

BUSLOLF BUSLOLF BUSLOLF 164,232 90.90%BUSMEDL BUSLOLF BUSLOLF 6,090 3.37%BUSMEDL BUSMEDL BUSLOLF 5,157 2.85%BUSLOLF BUSMEDL BUSLOLF 3,829 2.12%BUSHILF BUSLOLF BUSLOLF 412 0.23%BUSHILF BUSMEDL BUSLOLF 377 0.21%BUSHILF BUSHILF BUSLOLF 236 0.13%BUSLOLF BUSHILF BUSLOLF 200 0.11%BUSMEDL BUSHILF BUSLOLF 146 0.08%

180,679 100%

2002 through 2004

Count

Profile Segment Tracking of 2004 Business Low Load Factor

6

Load Factor Distribution of 2004 Business High Load Factor ESI IDs

• The 2004 BusHiLF group started with a population of 30,935.

• After applying the analysis criteria the sample size was 22,555

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

0.00to

0.04

0.05to

0.09

0.10to

0.14

0.15to

0.19

0.20to

0.24

0.25to

0.29

0.30to

0.34

0.35to

0.39

0.40to

0.44

0.45to

0.49

0.50to

0.54

0.55to

0.60

0.61to

0.64

0.65to

0.69

0.70to

0.74

0.75to

0.79

0.80to

0.84

0.85to

0.89

0.90to

0.94

0.95to

1.00

Load Factors

ES

I ID

s

2002 2003 2004

7

Load Factor Distribution of 2004 Business Medium Load Factor ESI IDs

• The 2004 BusMedLF group started with a population of 131,197.

• After applying the analysis criteria the sample size was 64,902.

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

0.00to

0.04

0.05to

0.09

0.10to

0.14

0.15to

0.19

0.20to

0.24

0.25to

0.29

0.30to

0.34

0.35to

0.39

0.40to

0.44

0.45to

0.49

0.50to

0.54

0.55to

0.60

0.61to

0.64

0.65to

0.69

0.70to

0.74

0.75to

0.79

0.80to

0.84

0.85to

0.89

0.90to

0.94

0.95to

1.00

Load Factors

ES

I ID

s

2002 2003 2004

8

Load Factor Distribution of 2004 Business Low Load Factor ESI IDs

• The 2004 BusLoLF group started with a population of 233,699.

• After applying the analysis criteria the sample size was 180,679.

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

0.00to

0.04

0.05to

0.09

0.10to

0.14

0.15to

0.19

0.20to

0.24

0.25to

0.29

0.30to

0.34

0.35to

0.39

0.40to

0.44

0.45to

0.49

0.50to

0.54

0.55to

0.60

0.61to

0.64

0.65to

0.69

0.70to

0.74

0.75to

0.79

0.80to

0.84

0.85to

0.89

0.90to

0.94

Load Factors

ES

I ID

s

2002 2003 2004

9

Load Factor Distribution of 2004 Business Load Factor ESI IDs

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

0.00to

0.04

0.05to

0.09

0.10to

0.14

0.15to

0.19

0.20to

0.24

0.25to

0.29

0.30to

0.34

0.35to

0.39

0.40to

0.44

0.45to

0.49

0.50to

0.54

0.55to

0.60

0.61to

0.64

0.65to

0.69

0.70to

0.74

0.75to

0.79

0.80to

0.84

0.85to

0.89

0.90to

0.94

0.95to

1.00Load Factors

ES

I ID

s2002 LF of '04 BusLo 2002 LF of '04 BusMed 2002 LF of '04 BusHI2003 LF of '04 BusLo 2003 LF of '04 BusMed 2003 LF of '04 BusHI2004 LF of '04 BusLo 2004 LF of '04 BusMed 2004 LF of '04 BusHI

10

Load Factor Boundaries Impact on Profile Segment Migration

66,384

61,777

66,411

61,642

57,207

60,773

56,489

52,31254,507

51,185

47,409

41,40739,346

31,703

83,160

44,209

71,463

30,000

40,000

50,000

60,000

70,000

80,000

AvgLF Lower / Upper Boundaries

Mig

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Fre

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