| A parabolic mirror is often used as a solar energy concentrator for generating electricity. A tracking system follows continuously the sun and keep its image on the axis of the mirror. To maximise the efficiency, ideally one should have a uniform radiance over the whole surface of the detector. To reduce the cost of the tracking system, it would also be desirable to keep uniform the radiance on the detector even when the sun is off axis. The objective of this thesis is to determine what new shape should take a parabolic solar concentrator to generate an uniform radiance distribution in its detecting plane for any position of the sun in an angular field of view of a few degrees. The optical design software CODE V of the company Optical Research Associates is the main tool we used, in particular its optimisation routine. We studied mirrors represented respectively by parabolic, aspherical and spline functions. Numerical results show that the design making use of spline functions to represent a mirror permitted to reach our objective. |
