Realistic ray-tracing model of a Scheffler reflector based on experimental data

A model of a Scheffler reflector with mirror facets is presented in the form of an open-source script for use with the free ray-tracing software Soltrace (Monte-Carlo method). It is calibrated to match the experimental results obtained with an 8 m 2 (surface area) reflector of 1.43 m focal distance. It is found that the optical errors of real reflectors (slope, specularity, shape) are very large, leading to results that are far from theoretical. A sensitivity study is then carried out to assess the level of importance of reflector and receiver positioning and adjustment to obtain maximum performance. The parametric study showed that the margin of error is quite small for north-south alignment, rotation axis adjustment, horizontal receiver position, declination adjustment and tracking system, with a performance reduction of 10% for errors of 1 degrees , 0 . 8 degrees , 6 cm, 2 days and 4 min, respectively. The inclination of the receiver has lower influence on the results. The performance of Scheffler reflectors could therefore be greatly enhanced by improving the shape and characteristics of the mirrors, taking particular care with the various settings. In addition, as an application example, a secondary optical system multiplying the power density by up to 3.3 is proposed.