The flux distribution from a 1.25m2 target aligned heliostat: comparison of ray tracing and experimental results

Abstract

The purpose of this paper is to validate SolTrace for concentrating solar investigations at CSIR by means of a test case: the comparison of the flux distribution in the focal spot of a 1.25 m2 target aligned heliostat predicted by the ray tracing model with the experimental flux distribution measured using a calorimeter. Preliminary results show that the near-Gaussian shape and radial extent of the flux distribution in the focal spot of the 1.25m2 heliostat is well predicted by ray-tracing simulation using SolTrace. The level of flux is underpredicted by about 50%, however. The uncertainty of the peak flux measurement was found to be between 16 and 21%, so any conclusions regarding the flux level predictive accuracy of SolTrace first require repeating the experimental measurements taking care to increase the sensitivity of the flux measurement.