Development of a flat-plate calorimeter for a small scale heliostat field

A small-scale heliostat field has been developed for use as an experimental test rig for concentrating solar power (CSP) research at the University of Stellenbosch, South Africa. The optical system is comprised of 150 mirror facets (100 x 100 mm) rigidly mounted on a dual axis rotating framework. Performance characterization of the small-scale rig is proposed using a flat-plate calorimeter designed to measure the concentrating solar flux. This paper addresses the methodology, design features, device calibration, overall heat transfer modeling, preliminary experimental results and final comparison with ray-tracing analysis. The modeling and preliminary testing results showed that the small-scale rig generates solar flux in the range of 950 W.