Optical Analysis of a Heliostat Array With Linked Tracking

Abstract

The optical performance of a novel solar concentrator consisting of a 400 spherical heliostat array and a linked twoaxis tracking system is analyzed using the Monte Carlo raytracing technique. The optical efficiency and concentration ratio are compared for four different heliostat linkage configurations, including linkages of 1 أ— 1, 1 أ— 2, 2 أ— 2, 4 أ— 4, and 5 أ— 5 heliostats for 7hour operation and the selected months of June and December. The optical performance of the concentrator decreases with the increasing number of heliostats in the individual groups due to increasing optical inaccuracies. In June, the bestperforming linked configuration, in which 1 heliostat in the eastwest direction and 2 heliostats in the northsouth direction are linked, provides a monthlyaveraged 7hour optical efficiency and average concentration ratio of 79% and 511 suns, respectively. In December, the optical efficiency and the average concentration ratio decreases to 61% and 315 suns, respectively.