Modelling of CPC-based photovoltaic concentrator

The optical modelling of a Compound Parabolic Concentrator (CPC), as photovoltaic solar light concentrator, shows that the light distribution on the circular receiver is far from being uniform, as requested for this type of application. The solution lies in the adding of a prismatic optical mixer, which breaks the circular symmetry of the CPC, distributing light over a square surface. This is paid by a ~30% reduction of the original CPC concentration ratio. The CPC-mixer system has been optimised for medium levels of concentration (~100). The optical efficiency of the CPC-mixer concentrator has been evaluated for different values of the walls reflectance, R, and a total loss of ~6% has been found for a 98% reflecting silver coated wall.