In electric power distribution and transmission system, coincident peak demand is the demand of individual customers or sub-systems that coincides (in time) with the peak demand of the whole system. For example, Customer A, B, and C are all sourcing their energy requirement from a main energy source or Substation D. Points A, B,C, and D all have electric meters. For a particular period, if electric meter D registers a peak demand of, say 1000MW at a particular time, the electricity demand registered by meters A, B, and C at that time is their coincident peak demand.
The non-coincident peak demand (NCP), on the other hand, is the actual individual peak demand of each individual customer or sub-system whose the time when the individual peak demand occurs does not necessarily coincides with time when the system peak happens. For example, the meter in D registers a peak demand at 1200H, while the individual peak demand or its non-coincident peak demand of customer A,B, and occurred at 1200H, 1100H, and 1130H, respectively
These concepts are essential the utilities’ system planning, particularly in system sizing and expansion programs, which could then be a basis of billing.