Terrestrial concentrating photovoltaic power system studies

Abstract

Studies aimed at defining the role of sunlight concentration in reducing the cost of electrical energy generated by terrestrial photovoltaic systems are described. These studies use computer modelling to (a) compare silicon cells and gallium arsenide cells in concentrating systems, (b) investigate the operation of photovoltaic systems in low insolation locations and (c) evaluate the effect of wind dependent thermal conductances on performance of passively cooled systems. Optimum fixed energy costs occur at higher aperature to cell area ratios for GaAs systems compared to silicon systems due to the better high temperature performance and increased costs of GaAs. Results based on currently available data show that concentrating systems should not be ruled out relative to fixed flat unconcentrated arrays even for low solar irradiation locations such as Cleveland. The wind dependent thermal conductance studies show that for precise modeling the effect of wind speed should be considered in locations having large wind speed deviations from the yearly mean. However, with the present uncertainties in cost inputs, the use of average values is quite appropriate.