The rate at which energy is used by the customer, or the rate at which energy is flowing through a particular system element, usually expressed in kilowatts or megawatts. Demand may be quoted on an instantaneous basis or may be averaged over a designated period of time. Types of demand are defined below.

  • Instantaneous demand: The rate of energy delivered at a given instant in time.
  • Demand interval: The time period during which electric energy is measured (e.g., in 15-, 30-, or 60-minute increments).
  • Peak demand: The highest electric requirement occurring in a given period (e.g., an hour, a day, month, season, or year).
  • Coincident demand: The sum of two or more demands that occur within the same demand interval.
  • Non-coincident demand: The sum of two or more demands that occur in different demand intervals.
[SourceThe Potential Benefits of Distributed Generation and Rate-Related Issues That May Impede Their Expansion, U.S. Department of Energy, February 2007, p.xvi]