Simulation of a desalination plant supplied by a photovoltaic array with management strategies*

Abstract

This paper describes a program developed to simulate and assess the project of a stand-alone seawater desalination plant fed by a photovoltaic array. Objectives of the program are to: • Define the correct dimension for some critical subsystems' models of the plant • Validate some design solutions chosen a priori • Compare different operation management strategies. Simulation of a yearly run of the plant meets the above objec tives, provided suitable models of the system hardware and operation control procedures are available. The program de veloped includes three main sections: (1) models of the system's major components (some models fit the operational character istic of the component, others are limited to the component's transfer function); (2) a stochastic model for prediction of the daily availability of solar energy, based upon the Markov-chain algorithm; and (3) systems control logic. The program has been used to simulate the annual operation of the system under different management strategies. Realistic input data was taken from records of observations from a near by meteorological station. The output data was the performance of the system in terms of electrical energy and drinkable water production in the year. The program was written in Fortran V, run on a Univac 1100/60 computer, and it occupies 11 Kbytes of memory. The simulation of one year of plant operation, with hourly steps, requires 425 Kbytes of memory for input and output data - the computation time amounts to about 9 s. The main routines structure allows utilisation in more general simulation programs in the area of conversion of natural energy resources.