Prototype optical modelling procedure and outdoor characterization of an embedded polyolefin crossed compound parabolic concentrator for integrated photovoltaic windows

We present a method to optically model prototypes pre- and post-manufacturing to incorporate material flaws and understand clearly the potential of designs at the prototyping stage of window integrated PV systems. A prototype Window Embedded Crossed Compound Parabolic Concentrator (WE-CCPC) made of plastic Topaz optics, arrayed within double glazed windows as a means to provide both electricity and natural sunlight to a building is presented. The outdoor performance of the prototype is characterized, and the theoretical and experimental results compared. The manufactured module was found to have an optical efficiency of 77% at normal incidence and an acceptance angle of 20°once realistic material and manufacturing considerations were incorporated. Optical losses such as the absorption, cell reflectance, slope errors and irradiance nonuniformity were found to decrease the acceptance angle significantly as all increase with increased incidence angle, accumulating to the ~15° of acceptance angle loss from the original modelling.