Historical estimation

The Historical estimation routine calculates average daily load shapes using data from historical reference days. IEE derives interval-by-interval averages from valid intervals from the three nearest days of the same or like day of the week.

Valid historical reference days are days that can be used in the three-day average. To be valid, reference days must meet the following conditions:

  • Same weekdays are the same day of week as the day being estimated. For example, when estimating data from a Monday, IEE selects a Monday reference day. For holidays, another holiday day is considered a same weekday, regardless of the day of the week. For example, to estimate a Monday holiday day, IEE might use a Friday holiday day.

  • Like days are the same type of day as the day that needs to be estimated. Type of day includes weekday, weekend, or holiday. The routine uses the holiday list defined in the estimation set to identify holiday day types.

  • Valid readings are those with a status of Passed Validation (PV) or Manually Accepted (MA). IEE does not use estimated reads to calculate the historical average.

  • IEE does not use days that include one or more readings that have a power outage reading status. Power failures often cause irregular usage patterns, which results in data that is not typical for the customer.

  • IEE uses stored data and data within the current period.

    • Stored Data. Stored data can be historical data or data up to the end of the calendar month that has already been stored in the database. The latter case is common when estimating data that has already been imported and that falls within a billing cycle.

    • Data Within the Current Period. If reference intervals are from within the set of data being validated and estimated, valid intervals are those which are not marked as needing estimation and that are not already estimated.

  • IEE chooses reference days that are closest chronologically to the data being estimated, regardless of seasonal crossover. This may include days after the day that requires estimation. If two potential reference days are equidistant from the day that requires estimation, IEE uses the earlier day first. For example, to estimate 2 June, IEE might use 19 May, 26 May, and 9 June.

IEE calculates an average daily profile according to the following hierarchy, listed in order of preference and availability:

  • 3 same days

  • 2 same days + 1 like day

  • 1 same day + 2 like days

  • 3 like days

  • 2 same days

  • 1 same day + 1 like day

  • 2 like days

  • 1 same day

  • 1 like day

If IEE can create a baseline profile, it estimates the data. Intervals that need to be estimated take their values from the baseline curve and receive a status of ESTIMATED and ESTHISTORICAL.

For more information about configuring this estimation routine, see Configuring estimation routines: Common parameters.