Photovoltaic System Performance Enhancement With Non-Tracking Planar Concentrators: Experimental Results and Bi-Directional Reflectance Function (BDRF) Based Modelling

Non-tracking planar concentrators are a low-cost method of increasing the performance of traditional solar photovoltaic (PV) systems. This paper presents new methodologies for properly modeling this type of system design and experimental results using a bi-directional reflectance function (BDRF) of non-ideal surfaces rather than traditional geometric optics. This methodology allows for the evaluation and optimization of specular and non-specular reflectors in planar concentration systems. In addition, an outdoor system has been shown to improve energy yield by 45% for a traditional flat glass module and by 40% for a prismatic glass crystalline silicon module when compared to a control module at the same orientation. When compared to a control module set at the optimal tilt angle for this region, the energy improvement is 18% for both system. Simulations show that a maximum increase of 30% is achievable for an optimized system located in Kingston, ON using a reflector with specular reflection and an integrated hemispherical reflectance of 80%. This validated model can be used to optimize reflector topology to identify the potential for increased energy harvest from both existing PV and new-build PV assets.