Analysis of the ERCOT IDR Threshold Requirement Presented by Bill Boswell PWG Meeting May 27, 2009

2 Round 1 load research kWh data was used in the analysis. The dollars were calculated by multiplying the kWh times the corresponding load weighted average MCPE for the corresponding LRS and profiled interval. Domains Analysis was used to calculate the mean LRS kWh and dollars and mean profiled kWh and dollars for each domain. A sample point was assigned to a domain when its 15 minute kWh peak fell in the domain range two times during the study period. The following three (3) domains were defined.  0 – 300 kW => Domain 1  301 – 500 kW => Domain 2  501 – 700 kW => Domain 3 Analysis Methodology

3 The profiled interval data for each sample point is calculated using the following procedure.  Sum the LRS intervals to get the daily kWh usage.  Select the profile such as BUSHILF COAST.  Calculate a scaling factor as : Scaling Factor = daily kWh usage / (total kWh profiled for day)  Scale the BUSHILF COAST profile to the usage for the ESIID by multiplying each interval of the standard BUSHILF COAST profile by the scaling factor. Analysis Methodology

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5 LRS kWh Intervals vs Profiled kWh Intervals Domain 1 - August 8-14, Min LRS kWh Means15 Min Profiled kWh Means COAST SOUTH SCENTNCENT

6 LRS kWh Intervals vs Profiled kWh Intervals Domain 1 - November 7-13, Min LRS kWh Means15 Min Profiled kWh Means COASTSOUTH SCENTNCENT

7 LRS kWh Intervals vs Profiled kWh Intervals Domain 1 - January 23-29, Min LRS kWh Means15 Min Profiled kWh Means COASTSOUTH SCENT NCENT

8 LRS kWh Intervals vs Profiled kWh Intervals Domain 1 - May 22-28, Min LRS kWh Means15 Min Profiled kWh Means COAST SOUTH SCENT NCENT

9 LRS kWh Intervals vs Profiled kWh Intervals Domain 2 - August 8-14, 2005 SOUTH SCENT NCENT COAST 15 Min LRS kWh Means15 Min Profiled kWh Means

10 LRS kWh Intervals vs Profiled kWh Intervals Domain 2 - November 7-13, 2005 COAST SOUTH SCENTNCENT 15 Min LRS kWh Means15 Min Profiled kWh Means

11 LRS kWh Intervals vs Profiled kWh Intervals Domain 2 - January 23-29, 2005 COASTSOUTH SCENT NCENT 15 Min LRS kWh Means15 Min Profiled kWh Means

12 LRS kWh Intervals vs Profiled kWh Intervals Domain 2 - May 22-28, 2005 COAST SOUTH SCENT NCENT 15 Min LRS kWh Means15 Min Profiled kWh Means

13 LRS kWh Intervals vs Profiled kWh Intervals Domain 3 - August 8-14, 2005 COAST SOUTH SCENT 15 Min LRS kWh Means15 Min Profiled kWh Means NCENT

14 LRS kWh Intervals vs Profiled kWh Intervals Domain 3 - November 7-13, 2005 COAST SOUTH 15 Min LRS kWh Means15 Min Profiled kWh Means NCENT SCENT

15 LRS kWh Intervals vs Profiled kWh Intervals Domain 3 - January 23-29, 2006 COAST SOUTH SCENT 15 Min LRS kWh Means15 Min Profiled kWh Means NCENT

16 LRS kWh Intervals vs Profiled kWh Intervals Domain 3 - May 22-28, 2006 COAST SOUTH NCENTSCENT 15 Min LRS kWh Means15 Min Profiled kWh Means

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21 Average Day Across the Study Period Domain 1 - COAST 15 Min LRS kWh Means15 Min Profiled kWh Means

22 Average Day Across the Study Period Domain 1 - NCENT 15 Min LRS kWh Means15 Min Profiled kWh Means

23 Average Day Across the Study Period Domain 2 - COAST 15 Min LRS kWh Means15 Min Profiled kWh Means

24 Average Day Across the Study Period Domain 2 - NCENT 15 Min LRS kWh Means15 Min Profiled kWh Means

25 Average Day Across the Study Period Domain 3 - COAST 15 Min LRS kWh Means15 Min Profiled kWh Means

26 Average Day Across the Study Period Domain 3 - NCENT 15 Min LRS kWh Means15 Min Profiled kWh Means