Is the Weight Worth It? PWG April 27, 2006

2 Introduction The Average Load Factor (AvgLF) used to determine Profile Segment assignment is a weighted average of the individual monthly load factors, where demand values are used to determine the weights A simple monthly load factor is calculated as: kWh / (days in period x 24) / max kW Would weighting by kWh result in a more representative Profile Type assignment? To illustrate how different weights can greatly affect the calculated Average LF... kW or kWh?

3 The Approach: Look at how the two weighting methods would have affected assignments for AV years 2003 thru 2005 Created a list of all ESI IDs that had a Load Factor-based Profile Type assignment in December 2002 To isolate the differences between the two methodologies, tracked a fixed set of ESI IDs; did not include those that would have shifted to something other than a Load Factor based Profile Segment (e.g., BUSNODEM) A First Step

4 Weighting by kWh Key Aspects of preliminary kWh-weighted BUS LF Segment Determination No ‘calendarizing’ of monthly reads Prorated kWh is utilized for May and April Missing values or values of zero (0) If kW or kWh is missing, then meter read not included in calculations If kW and kWh are zero (0), then treated as missing reads Do not change the existing assignment if less than 274 days (365 x 75%) of kW and kWh values are available kWh values are used to weight the monthly load factors (compared to kW values used in current method)

5 Preliminary Analysis Preliminary analysis highlighted how extreme kWh or kW values or values of zero (0) can greatly affect load factor calculation—regardless of the weighting method—and are problematic in efforts to assign the most representative Load Profile Type Consider the following actual record: extreme value 5

6 Preliminary Analysis Another actual record that highlights a type of problem... extreme value

7 A Shift... It appears at this point that addressing extreme input data is prudent prior to recommending any change in the BUS LF assignment methodology For example, consider: Exclude monthly load factors that are > 100% Minimum ADUse and/or kW values, or combination thereof Utilize two years of history to develop screening criteria for data Allow for less than 12 months of data for AvgLF calculation

8 Questions or Comments