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

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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.

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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.

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Profile Type/Weather Zone CharacteristicsWeather

Zone

Primary Voltage Mean Percent of Total Load (w/o

Oil/Gas)

Primary Voltage ESIID Count (w/o

Oil/Gas)

Primary Voltage Mean Percent of Total ESIIDs (w/o

Oil/Gas)

BUSHILF FWEST 40.3 802 35.9

BUSMEDLF FWEST 14.3 899 17.4

BUSHILF SOUTH 9.7 57 1.3

BUSLOLF FWEST 5.2 1009 9.1

BUSHILF NORTH 4.2 123 12.2

BUSMEDLF NORTH 4.0 90 2.5

BUSMEDLF SOUTH 2.0 35 0.3

BUSNODEM FWEST 1.6 216 1.2

BUSHILF WEST 1.5 24 2.5

BUSLOLF NORTH 1.3 96 1.0

BUSLOLF SOUTH 1.0 37 0.1

BUSMEDLF NCENT 1.0 123 0.3

BUSHILF NCENT 0.9 69 0.7

BUSHILF COAST 0.7 15 0.1

BUSMEDLF WEST 0.7 41 0.9

BUSMEDLF EAST 0.5 6 0.2

BUSLOLF WEST 0.4 30 0.3

BUSLOLF NCENT 0.3 87 0.1

BUSLOLF EAST 0.3 7 0.1BUSNODEM WEST 0.1 23 0.2

TOTAL 3791

Notes:

Study Period: 11/05 - 07/06

Bold rows indicate sufficient data was avaiable to calculate means. The results are plotted on the following slides.

Profile Type

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BUSHILF - FWEST

Primary Voltage Secondary Voltage

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BUSMEDLF - FWEST

Primary Voltage Secondary Voltage

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Primary Voltage Secondary Voltage

BUSHILF - SOUTH

8

BUSLOLF - FWEST Primary Voltage Secondary Voltage

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Primary Voltage Secondary Voltage

BUSMEDLF - NORTH

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Primary Voltage Secondary Voltage

BUSMEDLF - SOUTH

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BUSNODEM - FWEST Primary Voltage Secondary Voltage

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BUSHILF - WEST Primary Voltage Secondary VoltagePrimary Voltage Secondary Voltage

13

Primary Voltage Secondary Voltage

BUSLOLF - NORTH

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Primary Voltage Secondary VoltageBUSMEDLF - NCENT

15

Primary Voltage Secondary Voltage

BUSHILF - NCENT

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Primary Voltage Secondary VoltageBUSLOLF - NCENT

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Next Steps

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