Demand (also called load) represents the power (measured in kW or MW) that a customer or group of customers is using at a given time. Because supply and demand must always be in balance, facilities used to serve customers (such as generators and transmission and distribution lines) must have sufficient capacity to serve the maximum demand of all connected customers. Various categories of demand are considered in design and operations of electrical systems:

  • Aggregate demand is the total demand associated with a group of customers
  • Average demand is the amount of energy used during a time interval divided by the number of hours in the interval
  • Baseload demand is the minimum amount of power that is required for all hours across a time interval  
  • Coincident demand is a customer’s or a group of customers’ demand at a specific time of interest such as the time when load peaks on a specific distribution circuit or the time of the utility system peak load.
  • Non-coincident demand is a customer’s or group of customers’ maximum demand that occurs at any other point in time
  • Peak demand is the highest amount of power required during a time interval 


The chart above shows demand for a commercial building over a 24-hour period and illustrates various categories of demand.