1

ERCOT

Load Profile Transition Option 1 – 4 Analysis

August 21, 2006

2

Analysis Methodology• New profiles were simulated using the latest LRS results (reflecting 2006 AV Profile

ID assignments) and were compared to current profiles for 2005

• Data Aggregation process was approximated using a SAS program in conjunction with usage records pulled for 2006 Annual Validation

– Usage and profile data were structured to facilitate making multiple data aggregation runs over the April 1 – October 31 time period

– Code was written to approximate both Initial and Final settlements for all transition options being considered for all 6 Profile Types

– May 1 transition date was assumed in all cases

– Profiles were adjusted as needed to properly reflect the way a specific transition option would be implemented

– New profiles were considered to be loaded and available for settlement as needed back to January 1 of the transition year; old profiles were considered to be loaded and available through December 31 of the transition year

– Code was benchmarked against production settlement runs to confirm that reasonably accurate approximations were incorporated

3

Description of Option 1- Direct Cutover

– Start posting and using new profiles beginning on the transition date with no adjustments

– Continue the settlement process with no changes to the current settlement system following all current rules for data aggregation

4

Option 1 – Direct Cutover Residential Group Initial and Final

•Residential load aggregated using old profiles

Old Old + New % Difference

Option 1 Initial Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

Option 1 Final Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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ay

5

Option 1 – Direct Cutover Residential Group Initial and Final

Old Old + New % Difference

Option 1 Initial Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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ay

Option 1 Final Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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ay

•Residential load aggregated using old profiles

•Option 1 Residential load aggregation with a May 1 transition date

6

Option 1 – Direct Cutover Residential Group Initial and Final

•Residential load would be overstated for both initial and final settlement by as much as 20% for about the first month after the transition date

•Residential load would be understated by about 5% for about 2 weeks prior to the transition date for final settlement

Old Old + New % Difference

Option 1 Initial Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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ay

-50%

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-10%

0%

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% D

iffe

ren

ce

Option 1 Final Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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ay

-50%

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% D

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ce

7

Option 1 – Direct Cutover Business Group Initial and Final

Old Old + New % Difference

Option 1 Initial Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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ay

Option 1 Final Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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•Business load aggregated using old profiles

8

Option 1 – Direct Cutover Business Group Initial and Final

Old Old + New % Difference

Option 1 Initial Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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ay

Option 1 Final Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

•Business load aggregated using old profiles

•Option 1 Business load aggregation with a May 1 transition date

9

Option 1 – Direct Cutover Business Group Initial and Final

•Business load would be significantly understated by as much as 50% for initial settlements for about the first month after the transition date•Business load would be significantly overstated by as much as 40% for final settlements for about the first month prior to the transition date and as much as 30% for the first month after the transition date

Old Old + New % Difference

Option 1 Initial Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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ay

-60%

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-40%

-30%

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-10%

0%

10%

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% D

iffe

ren

ce

Option 1 Final Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

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-60%

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% D

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ren

ce

10

Option 1 – Direct Cutover Profile Total Initial and Final

Old Old + New % Difference

Option 1 Initial Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

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ay

-50%

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-20%

-10%

0%

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% D

iffe

ren

ce

Option 1 Final Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

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-50%

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ce

•Total profiled load would be understated by as much as about 20% for initial for about the first month after the transition date•Total profiled load would be overstated by about 15% for final settlements for about the first month prior to the transition date and understated by about 15% following the transition date

11

RES Base RES Option 1 Ratio Diff

Option 1 – Direct Cutover Profiled Load Ratio Share Initial and Final

• Substantial distortion in the Residential percentage of load occurs during the transition period both at initial and final settlement• Note : Business percentage of load = (100 – residential percentage of load)

RES Profiled Load Ratio ShareBase vs Option 1 - Initial Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

Lo

ad R

atio

Sh

are

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

1 -

Bas

e)

RES Profiled Load Ratio ShareBase vs Option 1 - Final Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayL

oad

Rat

io S

har

e

-25%

-20%

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-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

1 -

Bas

e)

12

Pros and Cons Option 1 – Direct Cutover

– Pro:• No system changes required either at ERCOT or in shadow

settlement systems– Con:

• Significant contribution to UFE– During the transition period UFE allocation will reduce the

miss-statement of Business load, but will increase the miss-statement of Residential load for all settlements

– IDR ESIIDs will be allocated UFE caused by the transition even though they are not involved in the profile changes

• Significant differences will occur between initial and final settlement … scheduling that’s right for one will be wrong for the other

• QSEs/CRs with large proportions of Business load will be affected most dramatically

13

Description of Option 4a-c – Graduated Option

– Transition from old to new profiles over a selected number of days– Transition profile = p × old profile + (1 – p) × new profile,

• Where p = percent of days through transition period

Bushilf - Option 4a - 50 Day TransitionkWh per Day - New ,Old, Transition

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

5/1/2007 5/15/2007 5/29/2007 6/12/2007

kWh

per

Day

14

Option 4a – Graduated Option 50 Day Transition Residential Group Initial and Final

•Residential load would be overstated for both initial settlement by as much as 10% for about the first two months after the transition date•Transition impact would be almost completely eliminated for Residential load at final settlement

Old Transition Profile % Difference

Option 4a Initial Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4a Final Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

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-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

15

Option 4a – Graduated Option 50 Day Transition Business Group Initial and Final

Old Transition Profile % Difference

Option 4a Initial Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

Option 4a Final Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

•Business load would be understated for initial settlement by as much as 30% for about the first three months after the transition date•Transition impact would be largely eliminated for Business load at final settlement

16

Option 4a – Graduated Option50 Day Transition Profile Total Group Initial and Final

Old Transition Profile % Difference

Option 4a Initial Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

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-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4a Final Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

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50%

% D

iffe

ren

ce

•Total profiled load would be understated for both initial settlement by as much as 10% for about the first three months after the transition date•Transition impact would be almost completely eliminated for total profiled load at final settlement

17

Option 4a – Graduated Option Profiled Load Ratio ShareInitial and Final

RES Profiled Load Ratio SharesBase vs Option 4a - Initial Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

Lo

ad R

atio

Sh

are

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

4a

- B

ase)

RES Profiled Load Ratio SharesBase vs Option 4a - Final Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayL

oad

Rat

io S

har

e

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

4a

- B

ase)

RES Base RES Option 4a Ratio Diff

• Substantial distortion in the Residential percentage of load occurs during the transition period at initial settlement only• Note : Business percentage of load = (100 – residential percentage of load)

18

Pros and ConsOption 4a – Graduated Option50 Day Transition

– Pro:• No system changes required either at ERCOT or in shadow settlement

systems• Eliminates the large load swing at the transition date present in Option 1

– Con:• ERCOT will have to calculate old, new and transition forecast and backcast

profiles for the entire transition period• Somewhat significant contribution to UFE at initial settlement over a three-

month time period• Somewhat significant differences will occur between initial and final

settlements for business load• QSEs/CRs with large proportions of Business load will be affected most

dramatically• QSEs/CRs will have to adjust their forecasts/schedules to implement the

old-to-new transition if they generate their own forecasts• CR product offerings will be more difficult to price• Transition impacts will extend into the summer months

19

Option 4b – Graduated Option100 Day Transition Residential Group Initial and Final

Old Transition Profile % Difference

Option 4b Initial Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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ay

-50%

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-20%

-10%

0%

10%

20%

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40%

50%

% D

iffe

ren

ce

Option 4b Final Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

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-30%

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0%

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50%

% D

iffe

ren

ce

•Transition impact would be almost completely eliminated for Residential load at both initial final settlement

20

Option 4b – Graduated Option100 Day TransitionBusiness Group Initial and Final

Old Transition Profile % Difference

Option 4b Initial Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

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% D

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ce

Option 4b Final Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

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0%

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% D

iffe

ren

ce

•Business load would be understated for initial settlement by as much as 20% for about the first four months after the transition date•Transition impact would be largely eliminated for Business load at final settlement

21

Option 4b – Graduated Option100 Day TransitionProfile Total Group Initial and Final

Old Transition Profile % Difference

Option 4b Initial Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

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ay

-50%

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-30%

-20%

-10%

0%

10%

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30%

40%

50%

% D

iffe

ren

ce

Option 4b Final Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

•Transition impact would be almost completely eliminated for Total profiled load at both initial final settlement

22

Option 4b – Graduated Option100 Day TransitionProfiled Load Ratio Share Initial and Final

RES Profiled Load Ratio SharesBase vs Option 4b - Initial Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

Lo

ad R

atio

Sh

are

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

4b

- B

ase)

RES Profiled Load Ratio SharesBase vs Option 4b - Final Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayL

oad

Rat

io S

har

e

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

4b

- B

ase)

RES Base RES Option 4b Ratio Diff

• Some distortion in the Residential percentage of load occurs during the transition period at initial settlement only• Note : Business percentage of load = (100 – residential percentage of load)

23

Pros and ConsOption 4b – Graduated Option 100 Day Transition

– Pro:• No system changes required either at ERCOT or in shadow

settlement systems• Eliminates the large load swing at the transition date present in

Option 1– Con:

• ERCOT will have to calculate old, new and transition forecast and backcast profiles for the entire transition period

• Somewhat significant differences will occur between initial and final settlements for business load

• QSEs/CRs with large proportions of Business load will be affected most dramatically

• QSEs/CRs will have to adjust their forecasts/schedules to implement the old-to-new transition if they generate their own forecasts

• CR product offerings will be more difficult to price

24

Option 4c – Graduated Option150 Day TransitionResidential Group Initial and Final

Old Transition Profile % Difference

Option 4c Initial Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4c Final Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

•Transition impact would be almost completely eliminated for Residential load at both initial final settlement

25

Option 4c – Graduated Option150 Day Transition Business Group Initial and Final

Old Transition Profile % Difference

Option 4c Initial Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

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30%

40%

% D

iffe

ren

ce

Option 4c Final Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

•Business load would be understated for initial settlement by as much as 10% for about the first six months after the transition date•Transition impact would be largely eliminated for Business load at final settlement

26

Option 4c – Graduated Option150 Day Transition Profile Total Group Initial and Final

Old Transition Profile % Difference

Option 4c Initial Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

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50%

% D

iffe

ren

ce

Option 4c Final Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

•Transition impact would be almost completely eliminated for Total profiled load at both initial final settlement

27

Option 4c – Graduated Option 150 Day TransitionProfiled Load Ratio Share Initial and Final

RES Profiled Load Ratio SharesBase vs Option 4c - Initial Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

Lo

ad R

atio

Sh

are

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

4c

- B

ase)

RES Profiled Load Ratio SharesBase vs Option 4c - Final Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayL

oad

Rat

io S

har

e

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

4c

- B

ase)

RES Base RES Option 4c Ratio Diff

• Small distortion in the Residential percentage of load occurs during the transition period at initial settlement only• Note : Business percentage of load = (100 – residential percentage of load)

28

Pros and Cons Option 4c – Graduated Option150 Day Transition

– Pro:• No system changes required either at ERCOT or in shadow

settlement systems• Eliminates the large load swing at the transition date present in

Option 1– Con:

• ERCOT will have to calculate old, new and transition forecast and backcast profiles for the entire transition period

• Somewhat significant differences will occur between initial and final settlements for business load

• QSEs/CRs with large proportions of Business load will be affected most dramatically

• QSEs/CRs will have to adjust their forecasts/schedules to implement the old-to-new transition if they generate their own forecasts

• CR product offerings will be more difficult to price

29

Description of Option 2 – Consumption Start Date Cutover

• ESIIDs having an actual meter reading (meter read spans trade day) available for settlement that starts before the transition date is settled with old profiles

• ESIIDs having an actual meter reading (meter read spans trade day) available for settlement that starts on or after the transition date is settled with new profiles

• ESIIDs settled with historical meter reads will be settled with old profiles if they will have an actual meter read spanning the trade day that starts before the transition date

• ESIIDs settled with historical meter reads will be settled with new profiles if they will have an actual meter read spanning the trade day that starts on or after the transition date

30

Option 2 – Consumption Start Date CutoverResidential Group Initial and Final

Old New Profile % Difference

Option 2 Initial Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 2 Final Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

•Transition impact would be almost completely eliminated for Residential load at both initial final settlement

31

Option 2 – Consumption Start Date CutoverBusiness Group Initial and Final

Old New Profile % Difference

Option 2 Initial Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

Option 2 Final Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

•Transition impact would be almost completely eliminated for Business load at both initial final settlement

32

Option 2 – Consumption Start Date Cutover Profile Total Initial and Final

Old New Profile % Difference

Option 2 Initial Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 2 Final Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

•Transition impact would be almost completely eliminated for Total profiled load at both initial final settlement

33

Option 2 – Consumption Start Date Cutover Profiled Load Ratio Share Initial and Final

RES Profiled Load Ratio SharesBase vs Option 2 - Initial Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

Lo

ad R

atio

Sh

are

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

2 -

Bas

e)

RES Profiled Load Ratio SharesBase vs Option 2 - Final Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayL

oad

Rat

io S

har

e

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

2 -

Bas

e)

RES Base RES Option 2 Ratio Diff

• No distortion in the Residential percentage of load occurs during the transition period• Note : Business percentage of load = (100 – residential percentage of load)

34

Pros and ConsOption 2 – Consumption Start Date Cutover

– Pro:• Eliminates the large load swing at the transition date

present in Option 1• Virtually eliminates the profile transition impact for all trade

days and settlements

– Con:• ERCOT will have to calculate and post both old and new

forecast and backcast profiles for a significant length of time• ERCOT and shadow system changes will be required to

properly select the appropriate old or new profile to use• For a given trade day following the transition date some

ESIIDs will be settled with old profiles and the others would be settled with new profiles … the mix would change continuously over the transition period

35

Description of Option 3 – Trade Day Cutover

• ESIIDs are settled with old profiles for all Trade days occurring before the transition date

• ESIIDs are settled with new profiles for all Trade days occurring on or after the transition date

36

Option 3 – Trade Day Cutover Residential Group Initial and Final

Old New Profile % Difference

Option 3 Initial Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 3 Final Settlement RESTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

•Transition impact would be almost completely eliminated for Residential load at both initial final settlement

37

Option 3 – Trade Day Cutover Business Group Initial and Final

Old New Profile % Difference

Option 3 Initial Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

Option 3 Final Settlement BUSTOTALAggregated Across Weather Zones

0

50,000

100,000

150,000

200,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

•Transition impact would be almost completely eliminated for Business load at both initial final settlement

38

Option 3 – Trade Day Cutover Profile Total Initial and Final

Old New Profile % Difference

Option 3 Initial Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 3 Final Settlement PROFTOTALAggregated Across Weather Zones

0

100,000

200,000

300,000

400,000

500,000

600,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

•Transition impact would be almost completely eliminated for Total profiledl load at both initial final settlement

39

Option 3 – Trade Day Cutover Profiled Load Ratio Share Initial and Final

RES Profiled Load Ratio SharesBase vs Option 3 - Initial Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

Lo

ad R

atio

Sh

are

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

3 -

Bas

e)

RES Profiled Load Ratio SharesBase vs Option 3 - Final Settlement

20%

30%

40%

50%

60%

70%

80%

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayL

oad

Rat

io S

har

e

-25%

-20%

-15%

-10%

-5%

0%

5%

10%

15%

20%

25%

Dif

f (O

pti

on

3 -

Bas

e)

RES Base RES Option 3 Ratio Diff

• No distortion in the Residential percentage of load occurs during the transition period• Note : Business percentage of load = (100 – residential percentage of load)

40

Pros and ConsOption 3 – Trade Day Cutover

– Pro:• Eliminates the large load swing at the transition date

present in Option 1• Virtually eliminates the profile transition impact for all trade

days and settlements

– Con:• ERCOT will have to calculate and post both old and new

forecast and backcast profiles for a significant length of time• ERCOT and shadow system changes will be required to

properly select the appropriate old or new profile to use

41

• Questions?

42

Review of Initial and Final Settlement Impacts for all Options

By Profile Group and Type

Appendix

43

Option 1- Direct CutoverReview of Initial and Final Settlement Impacts

By Profile Group and Type

44

Option 1 – Reshiwr Initial and Final

Old Old + New % Difference

Option 1 Initial Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 1 Final Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

45

Option 1 – Reslowr Initial and Final

Old Old + New % Difference

Option 1 Initial Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 1 Final Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

46

Option 1 – Bushilf Initial and Final

Old Old + New % Difference

Option 1 Initial Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

% D

iffe

ren

ce

Option 1 Final Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

47

Option 1 – Buslolf Initial and Final

Old Old + New % Difference

Option 1 Initial Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

Option 1 Final Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

48

Option 1 – Busmedlf Initial and Final

Old Old + New % Difference

Option 1 Initial Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

Option 1 Final Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

49

Option 1 – Busnodem Initial and Final

Old Old + New % Difference

Option 1 Initial Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 1 Final Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

50

Option 4a – Graduated Option

50 Day TransitionReview of Initial and Final Settlement Impacts

By Profile Group and Type

51

Option 4a – 50 Day Transition Reshiwr

Old Transition Profile % Difference

Option 4a Initial Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4a Final Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

52

Option 4a – 50 Day Transition Reslowr

Old Transition Profile % Difference

Option 4a Initial Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4a Final Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

53

Option 4a – 50 Day Transition Bushilf

Old Transition Profile % Difference

Option 4a Initial Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

% D

iffe

ren

ce

Option 4a Final Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

% D

iffe

ren

ce

54

Option 4a – 50 Day Transition Buslolf

Old Transition Profile % Difference

Option 4a Initial Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

Option 4a Final Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

55

Option 4a – 50 Day Transition Busmedlf

Old Transition Profile % Difference

Option 4a Initial Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

Option 4a Final Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

56

Option 4a – 50 Day Transition Busnodem

Old Transition Profile % Difference

Option 4a Initial Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4a Final Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

57

Option 4b – Graduated Option

100 Day TransitionReview of Initial and Final Settlement Impacts

By Profile Group and Type

58

Option 4b – 100 Day Transition Reshiwr

Old Transition Profile % Difference

Option 4b Initial Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4b Final Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

59

Option 4b – 100 Day Transition Reslowr

Old Transition Profile % Difference

Option 4b Initial Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4b Final Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

60

Option 4b – 100 Day Transition Bushilf

Old Transition Profile % Difference

Option 4b Initial Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

% D

iffe

ren

ce

Option 4b Final Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

% D

iffe

ren

ce

61

Option 4b – 100 Day Transition Buslolf

Old Transition Profile % Difference

Option 4b Initial Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

Option 4b Final Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

62

Option 4b – 100 Day Transition Busmedlf

Old Transition Profile % Difference

Option 4b Initial Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

Option 4b Final Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

63

Option 4b – 100 Day Transition Busnodem

Old Transition Profile % Difference

Option 4b Initial Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4b Final Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

64

Option 4c – Graduated Option

150 Day TransitionReview of Initial and Final Settlement Impacts

By Profile Group and Type

65

Option 4c – 150 Day Transition Reshiwr

Transition profile = p × old profile + (1 – p) × new profile, Where p = percent through transition period

Old Transition Profile % Difference

Option 4c Initial Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4c Final Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

66

Option 4c – 150 Day Transition Reslowr

Old Transition Profile % Difference

Option 4c Initial Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4c Final Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

67

Option 4c – 150 Day Transition Bushilf

Old Transition Profile % Difference

Option 4c Initial Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

% D

iffe

ren

ce

Option 4c Final Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

% D

iffe

ren

ce

68

Option 4c – 150 Day Transition Buslolf

Old Transition Profile % Difference

Option 4c Initial Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

Option 4c Final Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

69

Option 4c – 150 Day Transition Busmedlf

Old Transition Profile % Difference

Option 4c Initial Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

Option 4c Final Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

70

Option 4c – 150 Day Transition Busnodem

Old Transition Profile % Difference

Option 4c Initial Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 4c Final Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

71

Option 2 – Consumption Start Date Cutover

Review of Initial and Final Settlement Impacts

By Profile Group and Type

72

Option 2 – Reshiwr

Old New Profile % Difference

Option 2 Initial Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 2 Final Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

73

Option 2 – Reslowr

Old New Profile % Difference

Option 2 Initial Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 2 Final Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

74

Option 2 – Bushilf

Old New Profile % Difference

Option 2 Initial Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

% D

iffe

ren

ce

Option 2 Final Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

% D

iffe

ren

ce

75

Option 2 – Buslolf

Old New Profile % Difference

Option 2 Initial Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

Option 2 Final Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

76

Option 2 – Busmedlf

Old New Profile % Difference

Option 2 Initial Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

Option 2 Final Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

77

Option 2 – Busnodem

Old New Profile % Difference

Option 2 Initial Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 2 Final Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

78

Option 3 – Trade Day CutoverReview of Initial and Final Settlement Impacts

By Profile Group and Type

79

Option 3 – Reshiwr

Old New Profile % Difference

Option 3 Initial Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 3 Final Settlement RESHIWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

80

Option 3 – Reslowr

Old New Profile % Difference

Option 3 Initial Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 3 Final Settlement RESLOWRAggregated Across Weather Zones

0

25,000

50,000

75,000

100,000

125,000

150,000

175,000

200,000

225,000

250,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

81

Option 3 – Bushilf

Old New Profile % Difference

Option 3 Initial Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

% D

iffe

ren

ce

Option 3 Final Settlement BUSHILFAggregated Across Weather Zones

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

50,000

55,000

60,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

% D

iffe

ren

ce

82

Option 3 – Buslolf

Old New Profile % Difference

Option 3 Initial Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

Option 3 Final Settlement BUSLOLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

% D

iffe

ren

ce

83

Option 3 – Busmedlf

Old New Profile % Difference

Option 3 Initial Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

Option 3 Final Settlement BUSMEDLFAggregated Across Weather Zones

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-60%

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

% D

iffe

ren

ce

84

Option 3 – Busnodem

Old New Profile % Difference

Option 3 Initial Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade Day

MW

h p

er D

ay

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce

Option 3 Final Settlement BUSNODEMAggregated Across Weather Zones

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

03/31/05 05/20/05 07/09/05 08/28/05 10/17/05

Trade DayM

Wh

per

Day

-50%

-40%

-30%

-20%

-10%

0%

10%

20%

30%

40%

50%

% D

iffe

ren

ce