Corporate

Profiling Overview

The generic Dominion Virginia Power and generic Dominion North Carolina Power customer class load profiles provide energy suppliers with important information on typical load profiles for specific classes of customers. The profiles may be helpful in preparing daily pre-scheduled loads. The profiles represent the average customer's usage pattern within that specific class and are based on annual load research class studies.

Customer class profiles are categorized as one of :

  • Weather Sensitive Profile
  • Historical Julian Profiles
  • Julian Lookup and Deemed Profiles

Weather Sensitive Profile

For customer classes that show a correlation between temperature and load, a weather response profile is provided. Hourly profiles are provided by season and day type. (The definitions for seasons and holidays are found at the end of this section.) Each hour will have two or more profile algorithms based on temperature ranges (T-min and T-max). Customer load is made up of some combination of base load and weather responsive load:

Base load

Plus (degrees Fahrenheit X Temp. variable)
Plus (relative humidity X RH variable) – optional for summer season only
Plus (wind speed MPH X Wind variable) – optional for winter season only
____________________________________________________________
Equals Total predicted load in kW

Base load represents base usage that is expected regardless of temperature, such as lighting and certain appliances. The weather responsive component represents comfort conditioning and other temperature sensitive load(s) and will have an increasing impact as temperatures move toward extremes. Wind speed in the winter and humidity in the summer will make modest contributions to predicted load.

Suppliers must obtain forecasted temperature, humidity, and wind speed to prepare their forecasted load (or they may utilize an advisory load forecast provided by Dominion.) Dominion provides the temperature, wind and humidity variables in the appropriate weather sensitive profile spreadsheets.

Example of partial spreadsheet:

Generic RESVA Profile
Fall Season Three Day Type (Weekday, Saturday, Sunday)        
                 
Retail Account Season Day Type  Hour T min T max Constant Temp RH  Wind
                 
RESVA Internal Fall Saturday 1 0 53 2.832374 -0.03856    
RESVA Internal Fall Saturday 2 0 55 2.626553 -0.03578    
RESVA Internal Fall Saturday 3 0 55 2.575818 -0.03564    
RESVA Internal Fall Saturday 4 0 55 2.687809 -0.03806    
RESVA Internal Fall Saturday 5 0 55 2.69383 -0.03786    
RESVA Internal Fall Saturday 6 0 55 2.891702 -0.04066    
RESVA Internal Fall Saturday 7 0 54 2.959144 -0.03871    
RESVA Internal Fall Saturday 8 0 55 3.122688 -0.03622    

Calculation:

  • Select the customer group to be profiled (in this example “RESVA”), then select the appropriate season/day type (in this example “Fall Saturday”) and then select the desired hour (in this example hour 1.) Note that hour 1 is for the time between midnight and 1:00 a.m.
  • Look at the T-min and T-max ranges in that hour’s row and select the variables in that range for the forecast. This example of a partial sheet illustrates just the lowest temperature range. There will be additional columns in the complete sheet for higher temperature ranges. In this example, the forecast load will be:

    Forecast kW = 2.832374 + (temp)(-0.03856) + (Rel. Hum.)(0) + (Wind)(0)
     
    Assuming a temperature forecast of 49 degrees F at this hour, relative humidity of 20% and wind speed of 12 MPH, the formula predicts that the average customer will use:

    Forecast kW

     =  2.832374 + (49)(-0.03856) + (.20)(0) + (12)(0)

     

     = 2.832374 + (-1.88944) + (0) + (0)

     

     = 0.942934 

The following classes have weather responsive profiles and are linked to their downloadable profile, for further reference:

Residential – Virginia
GS1
GS2
Commonwealth of Virginia 5VA
Commonwealth of Virginia 6VA
County/Municipal – Virginia
Residential – North Carolina
SGS - North Carolina

Holiday Definition

The following holidays are observed by NERC and are used for profiling:

New Year's Day
Memorial Day
Independence Day
Labor Day
Thanksgiving Day
Day after Thanksgiving
Christmas Eve
Christmas Day

Definition of Seasons

For the purposes of load profiling, the seasons are defined as follows:

Summer - June 1 - August 31
Fall -  September 1 - November 30
Winter - December 1 - February 28/29
Spring - March 1 - May 31

Historical/Julian Profiles

These profiles rely on time of year and day of week as the best predictor of customer load. The profiles may have a small degree of weather sensitivity that will be reflected in historical usage patterns, as you would expect. These profiles will contain a date and day of week label followed by the 24 hourly average energy values. To forecast the first non-holiday Monday in January, look up the first non-holiday Monday in January for the previous year. These classes use a Julian sort concept, mapped into the forecast year’s weekday/holiday matrix. (The definition of holidays is found in the previous section.)

The Church class is a good example of this type of profile. An historic Sunday or Wednesday will provide the best relative predictor of a future Sunday or Wednesday load for the same relative week of the year. In this way, comfort conditioning for either heating or cooling is also considered.

Other Generic Class Profiles listed here are normally forecast based on the individual customer’s interval data recorder. The Generic Class Profile will be referenced only in the rare case when a customer is so new that insufficient history exists to forecast their load.

The following classes have Historical Julian profiles and are linked, for reference, to their unbundled rate schedule:

Church

Generic profiles are provided but rarely used for the following classes:

GS3
GS4
LGEMLP
LGSNC
MS

Julian Look-up and Deemed Profiles Overview

Lighting Profile:
This deemed profile assumes about 4,000 hours annual lighting use for residential watch lights and street light customers. This profile is applied as a Julian date profile as the hours of darkness increase through the fall and the winter then decrease in the Spring/ summer. The profile consists of “0” when lights are deemed “off” and “1” when lights are deemed to be “on.” To develop a leap-year version of this file simply repeat the on/off pattern for February 28 for February 29.

FLATONE Profile:
This deemed profile is used for loads that are considered to be regularly “on” all of the time, such as traffic control. This profile consists of all “1” for every hour. To develop a leap-year version of this file simply repeat the final row to create a 366th observation.

FLATZERO Profile:
This deemed profile is used for loads that are forecast to be regularly “off” all (or nearly all) of the time, such as curtailable load and standby generation. This profile consists of all “0” for every hour. To develop a leap-year version of this file simply repeat the final row to create a 366th observation.

Other related link:

NYSE : (April 17, 2014) D 70.67 -0.86