Letter to the Editor—A Note on the Analysis of Peak-Demand Forecasts of an Electrical Utility

This note analyzes the peak-demand predictions of the Commonwealth Edison Company of Illinois in order to detect and isolate the effects of systematic factors on the distribution of prediction errors. The results show that the major factor affecting the distribution is the month for which peak demand is predicted but that the time interval between prediction and realization has only a slight effect on the prediction errors.