Configuring meter data accruals

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Interval meter data is typically sent to and loaded in IBM® Envizi ESG Suite within 24 hours of the data being recorded in a system metering device. However, there can be situations where data is sent to Envizi more than 24 hours after the data is recorded, or data may fail to arrive and be processed, which can result in missing records. Envizi provides the ability to accrue interval meter data to estimate the missing records.

You can view accrued data in the Meter Summary view. The interval chart builder can be configured to show accrued data against actual data. When you extract interval meter data in bulk, accrued data is flagged as estimated data if running the bulk extract using the standard format. If using the horizontal format, accrued data will be flagged with S, which is an abbreviation of system generated, as the data quality flag.

Note: When accrued meter data is overwritten with actual data, the Daily Data view of the meter takes up to 24 hours to completely update all fields, such as the Process Details or Received On fields.
System administrators can use the following steps to configure interval meter data accruals:
  1. In IBM Envizi ESG Suite, click Admin > Interval Meter Settings.
  2. Click Data validation and correction.
  3. For Meter Accrual Feature, select Yes.
  4. Configure additional options related to the period that the accrual will apply to:

    You are provided an option to specify the number of days from the current date that the accrual will apply to. A negative offset counts back the number of days from today’s date, up to -3 days from today's date. For example, a start period of -2 will mean the accrual period will look back 2 days from today's date and determine if an accrual is required. If no data is loaded looking back 2 days from today's date, then the accrual will generate from that date.

    If the end period of the cease date is set to also be -2, then the accrual will only apply the date 2 days back. If the cease date is set to be -1, then the accrual applies from 2 days and up to 1 day back, essentially providing an accrual covering 2 days.

    A positive offset value will provide an accrual into the future, up to 3 days into the future. For example, if the start period for the offset is set to -1 and the cease date is set to +2, it will accrue values covering yesterday and 2 days into the future.

    After being configured, this process occurs every day on a rolling basis, and will continue to evaluate if an accrual is required for the specified period each day.

Configuring accrual methodology

Before Envizi ESG Suite can apply an accrued value to the dates specified, it needs to know what methodology to use when deriving the accrued value. This is done by selecting an expected profile. An expected profile is a method to estimate the accrued value for each interval period within a day:
Historical

The Historical option uses a rolling average function looking back a specified period of time (e.g the prior 4,8 & 12 weeks, or 4,8,12 weeks in the prior year). When determining the rolling average function, day of week is also considered. For example, if Historical (Previous 4 weeks) is selected, and a accrual is required to be generated for a Monday, the accrued value will be based on a rolling average of the last 4 Mondays.

Normalized
The normalized methodology uses a regression model to determine the expected energy consumption for a given day. The profile is derived from using one of the selected options:
  • Previous 4 weeks
  • Previous 8 weeks
  • Previous 12 weeks
  • Previous 4 weeks last year
  • Previous 8 weeks last year
  • Previous 12 weeks last year

After the profile has been derived, the magnitude of the profile is then adjusted to reflect the modeled expected energy consumption.

Like Weather Day
The Like Weather Day profile considers performance on like weather days when determining the expected profile. This approach is only applicable when we have forecast weather or temperature information available for a given weather station. The Like Weather Day profile is best applied when dealing with an environment that has consistent operating conditions and has electrical loads that are weather sensitive, such as heating, ventilation and air conditioning, for example, fans, pumps, chillers, boilers, chillers, cooling towers.