Important aspects of electricity system planning are overall yearly electricity consumption and information about variations in consumption. These variations will influence the capacity that has to be installed, as well as the type and quantity of fuel that will be used. Using only economic, socio-economic, technical and meteorological indicators, we have developed a model that can predict the hourly load shape. This model is based on a division of the total electricity-consumption into 60 economic sectors and electrical appliances. For each of these sectors, a load shape is formed. Summation over sectors then gives the total hourly electricity consumption pattern. To test this model, the hour-to-hour load shape of the Dutch public grid for 1980 was formulated and compared with the actual load shape. The root-mean-square difference between the estimated and actual load shapes is 5% of the mean hourly load. The accuracy of the estimated maximum load for every week is of the same magnitude as that used for electricity-supply system planning over the short term. We conclude that our model can be used for long-term load shape forecasting.

The restructuring of the Netherlands power supply has resulted in break up into a production and a distribution sector. There has also been an amendment of the term "east saving" on which the distributor's back supply compensation is based: three tariffs are now announced, with confusing effect. This paper gives a new proposal for the compensation, based on the actual nett cost saving. This provides 8.4 cent/kWh compensation in the daylight hours in the months November to February, and 4.2 cent/kWh in the daylight hours of the remaining months. (R.H.)

A model for the simulation of autonomous energy systems using wind and solar power with Diesel back up is described. The model, known as SOMES, uses a statistical approach for the evaluation of wind energy fluctuations. The application of SOMES to an operating wind/Diesel system gave satisfactory results.

In electricity systems in which wind generators and photovoltaic cells play a large part in the production of electricity, a major problem is the matching of production and demand. This problem can be solved by means of storage facilities together with back-up generating capacity. To analyse the value of short-term as well as long-term storage facilities, a computer model has been developed which can simulate electricity systems that are fed largely by renewable energy sources. A brief description of the model is given. With this model calculations have been made for a possible situation where electricity in the Netherlands is supplied mainly by wind generators and PV cells, whereas and combined cycle units and gas turbines are used as back-up power.

In the analysis of industrial energy use, detailed information on the time patterns and simultaneity of demand for energy carriers provides a basis for studying various possibilities of improving the structure of industrial energy use. This article describes the results of an investigation of the energy use patterns in six branches of industry: paper and board, meat products, dairy products, beet sugar, starch and starch derivatives, beer and malt. The results have been used to estimate the potential for cogeneration of heat and electric power in these industry branches.