Statistical distribution of customer load profiles

The electric utilities need data from customer loads for many purposes. Load research has been activity to collect load data, analyse it and further distribute the results for management and engineers in an electric utility. The Finnish load research project has developed customer class hourly load models for one year with average load values and standard deviation. In many cases in distribution planning or pricing applications the confidence intervals must be approximated for distinct customers or small groups of customers. The simple use of normal distribution will not give reliable estimations for confidence intervals of one customer. Therefore more information is needed from distributions of customer load profiles. The Finnish load research project has studied the disaggregated load distributions of different customer categories. In this report the study of distribution functions of customer load profiles is reported and some results explained. Also some background theory is reviewed.