This article discusses the forecasting of load for a period varying from an hour to a week. As usual for the modelling and prediction of nonlinear processes, the use of artificial neural nets appears very promising. In the project described, measured loads for the past seven days, those for the two preceding days, maxima and minima of average temperatures of the previous day, and predicted day temperatures were used as input values, with the day of the week and day of the year as indicators. The load and temperature are modelled separately. An automated method is used for online testing