Computation of Loss-of-Load Probability

When the reliability of an electric power system is evaluated by the Loss-of-Load Probability (LOLP) method, it is customary to take into account the uncertainty in load forecasts by associating a peak-load distribution (as a parameter expressing the uncertainty) with the assumed daily peak-load duration curve, then to compute the unconditional LOLP as an average of the conditional LOLP weighted by the parameter distribution. In this note it is shown that an alternate and simpler procedure results when first the daily peak-load curve is modified so that the uncertainty is incorporated in it, then the usual LOLP method is applied.