Compact solar concentrator designed by minilens and slab waveguide

Solar power is a supplying inexhaustibly, causing no pollution, requiring slightly maintenance economic energy source. Currently, very high efficiency solar cells based on III-V semiconductors are available on the market. Since these solar cells are more expensive than silicon or thin film ones, they need to be used at high concentration ratio to reduce III-V multi-junction solar cell area. Concentrated photovoltaic (CPV) system is to collect light by using low-cost optical elements so that the total cost can be reduced. This paper presents a new design of solar concentrator for III-V concentrated photovoltaic. Minilens array focus sunlight to the triangular prisms causing traveling wave by total internal refraction in the waveguide. High efficiency solar cell is placed on the sidewall of the waveguide. The light and thin optical system could be fabricated by low-cost process and have the linear property for the tilt of the sun light. As a result, the sun tracker works only nine times a day accompanying by linear-moving waveguide. It also reduces the cost by decreasing the electricity demand for tracking system. © 2011 SPIE.