Off-axis aberration correction surface in solar energy application

A new fixed aberration correction surface for applications in solar energy is proposed. The surface equation was derived based on the theory of focusing heliostat and the technique of canting the mirror array at a particular incident angle. The performance of the optimized new surface is simulated and compared with that of a spherical surface for two different ranges of incident angles, i.e., 0°–33° and 33°–57°. The comparison result shows that there are considerable improvements: not only is the size and concentration of the sun’s image improved, but it is also possible to shift the hot spot from noon time to early morning and late afternoon.