A NOVEL 500W PHOTOVOLTAIC CONCENTRATOR

摘要

This paper describes the design of a new linear concentrating PV (CPV) module based on the Slat-Array Concentrator (SAC). The device was conceived as a demonstrational prototype for future photovoltaic power generating modules having a significantly reduced area of PV cells. A new R&D project, supported by the California Energy Commission and Sacramento Municipal Utility District in 2001-2004, views SAC as an efficient and lower cost alternative to the commonly used concentrators which can make better use of the direct solar radiation particularly through the electricity generation. The new CPV module has a total active collector area of 30 ft2 (about 2.8 m2) and weights about 10 kg/m2 which includes a support frame. The wind drag is greatly reduced in this concentrator due to its open-latticework configuration. It is designed to operate at the geometrical concentration ratio of 20 suns and power capacity of about 500 Watts when high-efficiency cells are employed. It can also be used with conventional PV cells adapted to higher- density fluxes, e.g., quality monocrystalline silicon cells manufactured with narrower grid line spacing. Due to an optimized design, the concentrated flux is distributed about evenly across the PV receiver. The module was mounted on a biaxial tracker to maximize the energy output during the day and tested using a PV receiver with known characteristics. Flux maps were also obtained using digital imaging of the concentrator?s focal spot and compared to the irradiance profiles predicted from raytracing.