Operational Cost Savings of Direct Load Control

Direct load control -- load which is under the control of the system dispatcher, such as could be the case under say demand subscription service -- can be used to reduce system spinning reserve. Such a reduction may constitute a significant additional saving in system variable cost. The objective of this paper is to evaluate the viability of this philosophy. A quasi-static system simulation algorithm is employed to compute the potential variable cost saving for a sample system consisting of thermal generation and direct load control. This algorithm considers probabilistic load models, outage probabilities and reliability economics.