The role of view factors in solar photovoltaic fields

The solar radiation on photovoltaic collectors in a solar field, deployed in multiple rows, consists of the direct beam, diffuse and reflected radiation. The amount of the diffuse and reflected radiation on the collector depends on view factor of the collector to sky, to ground and to surrounding objects. As shading takes place in the PV field, part of the ground between the collector rows may be shaded and another part may not be shaded, at any instant of time. To calculate the incident radiation of a PV field it is important to calculate the various types of view factors. In this paper, analytical expressions and numerical values of view factors were developed between collectors to sky F_sky, between opposite collectors F_A→H, and between collectors to shaded F_grd.s and not shaded F_grd.us grounds, for the front and rear sides of the collectors deployed on horizontal and inclined planes.