Questions about solar load model ( How to define albedo, when is view factor needed?)
 

I am stuck at this problem for fairly a long time where I have to calculate the total irradiance on rear side of bifacial solar panel. The solar radiations coming on the rear side are diffuse radiations and radiations reflected from ground (albedo). I am attaching picture for different types of radiations coming at the rear side. I want to know the following:

1) Is view factor model along with solar load model needed for this purpose or not? View factor model with solar load is not giving me any qr variation so I used solar load model only.

2) How is albedo defined in openfoam constant solar load model where the direct and diffuse solar rad is given by user? In fair weather model, it asks for ground reflectivity but how to enter ground reflectivity value for constant solar load model? Or do I need to use view factor modeling to accommodate this reflection in constant solar model?

Please guide!

Thanks!