A Study of Reflector-Enhanced Bifacial PV

Bifacial solar PV is a promising technology that can increase the amount of power generated by harvesting power on both sides of a module. Understanding how best to configure the geometry of these bifacial solar collectors is non-trivial as many geometric factors (tilt, ground reflectance (albedo), height above ground, row spacing, module spacing) tend to be interdependent, requiring a case by case analysis in order to optimize the total power output and maintain the frontside incident irradiance while maximizing the backside gain. In addition, as with monofacial modules, use of planar reflectors can be a cost effective way of increasing the incident irradiance, in the case of bifacial modules, on both sides of the module. However, the addition of reflectors adds to the challenge of optimizing the system configuration. The work described here presents an experimental and modeling study of reflector enhanced bifacial modules. Experiments were conducted on bifacial modules with and without reflector augmentation and compared against monofacial PV modules, assessing the effects of specular and diffuse reflectors. A model was developed to calculate the incident and reflected irradiance on the front and back sides of the modules. Beam insolation components were handled with ray tracing and sky and reflected diffuse components were handled with view factors.