1. Comparison of Average Daily Profiles for Primary vs Secondary Service Business Customers presented by ERCOT Load Profiling for the PWG Meeting of July 24-25, 2007

2. 2 Study Purpose In future load research samples, should a separate stratum for primary service be established where applicable? Should primary service be a separate profile type? Introductory presentation to the PWG as a first step.

3. 3 Study Details Study period: January 2005 thru July 2006 Business only profile types were included in the analysis. Oil/Gas sample points were removed using AEP and TXU lists. Load from primary service as an average percent of total load across the study period was calculated by Profile Type and Weather Zone and ranked in descending order. The calculation is defined as follows: Percent_Load_Primary_wo_OG = Kwh_Primary_wo_OG / (Kwh_Primary_wo_OG + Kwh_Secondary_wo_OG) * 100.0 Then Percent_Load_Primary_wo_OG is averaged across the study period. Combined ratio analysis was performed for separate primary and secondary service strata and the mean kW’s are plotted for average days by month by Profile Type and Weather Zone. Some Profile Type/Weather Zone combinations were excluded because there was not enough interval data to complete the ratio analysis.

4. 4 Profile Type/Weather Zone Characteristics

5. 5 BUSHILF - FWEST Primary Voltage Secondary Voltage

6. 6 BUSMEDLF - FWEST Primary Voltage Secondary Voltage

7. 7 Primary Voltage Secondary Voltage BUSHILF - SOUTH

8. 8 BUSLOLF - FWEST Primary Voltage Secondary Voltage

9. 9 Primary Voltage Secondary Voltage BUSMEDLF - NORTH

10. 10 Primary Voltage Secondary Voltage BUSMEDLF - SOUTH

11. 11 BUSNODEM - FWEST Primary Voltage Secondary Voltage

12. 12 BUSHILF - WEST Primary Voltage Secondary Voltage Primary Voltage Secondary Voltage

13. 13 Primary Voltage Secondary Voltage BUSLOLF - NORTH

14. 14 Primary Voltage Secondary Voltage BUSMEDLF - NCENT

15. 15 Primary Voltage Secondary Voltage BUSHILF - NCENT

16. 16 Primary Voltage Secondary Voltage BUSLOLF - NCENT

17. 17 Next Steps Consider introducing Primary as a new profile type based on the results from the Round 2 sample.