A 25m2 Target-Aligned Heliostat with Closed-Loop Control

A 25m2 target-aligned research heliostat with closed-loop control, with a theoretical concentration of 80 suns, has been built at CSIR in South Africa. The heliostat has four degrees of freedom: Azimuth, Elevation, Rotation and Pitch. A control system making use of a solar tracker has been developed and tested on a 1.25m2 target-aligned miniheliostat. A tracking accuracy of 3.3 milliradians was obtained. A good focal spot has been obtained with the 25m2 target-aligned research heliostat.