What is the signage of the BackShd term. Is the loss being subtracted from rear irradiance or added to it?
If the signage is negative- why is it being subtracted? Isn't GloBak (global irradiance on the rear side) achieved by already accounting for the shading losses? The flow diagram in the PVsyst report indicates it and the calculation checks out as well. Aren't we double counting?
If the signage is positive, why are we adding it back? Is it to match the PR measured on site where the rear irradiance may be measured by rear POA sensors that are mounted on the torque tube and hence not accounting sufficiently for the rear shading factor?
