View Factor Model and Validation for Bifacial PV and Diffuse Shade on Single-Axis Trackers

In this paper, we use a model based on view factors to estimate the irradiance incident on both surfaces of a single-axis tracker PV array for given direct and diffuse light components of the sky dome. We describe the mathematical formulation of the view factor model that assumes a 2D tracker geometry with Lambertian surfaces while accounting for reflections from all surrounding surfaces. The model allows specifically to calculate the incident irradiance on the back surface of PV modules as well as the diffuse shading effects caused by the presence of neighboring tracker rows in a PV array. We present preliminary results on an experimental validation of the view factor model.