ASSESSMENT OF SOLAR ENERGY POTENTIAL FOR A RADIALLY STAGGERED HELIOSTATS FIELD USING SUN TRACKING METHOD

Abstract

This article deals with the potential assessment of tower type solar thermal power system. An algorithm was developed to employ sun-tracking method, which provides the characteristic angles of the heliostats such that the incoming beams of sun rays are reflected to the receiver. A suite of MATLAB code was developed to implement the mathematical models for a quick evaluation of solar energy potential in a radially staggered heliostat field for the capital city of Kingdom of Saudi Arabia, Riyadh. An existing clear-sky model in the literature was used to compute hourly insolation. Optical efficiencies and heat collected by the receiver (from individual heliostat in the field on hourly basis) were computed and the monthly-averaged daily results were presented zone-wise and for the complete heliostat field. It was observed that the optical efficiency of the heliostat decreases with increasing distance from the receiver tower; this was due to increasing spillage of the reflected rays and decreasing cosine efficiency with increasing distance of the heliostat from the receiver tower. Results showed that annual average optical efficiency of the field is nearly forty-nine percent.