Inputs for Module Performance Model

The module performance model calculates the electrical output of the modules based on the irradiance value and the cell temperature (see Cell Temperature)

SolarFarmer runs the module performance model multiple times using four irradiance values:

• Effective irradiance, denoted \(G_{\text{eff}}(j,t)\). This is \(G_\text{eff,back,transmission}\) from Bifacial, and so sometimes referred to as the irradiance after bifacial transmission loss. For monofacial modules this is equivalent to the irradiance after the spectral effect, \(G_{\text{spectral}}\). It uses the proportion of direct irradiance that not shaded. This value is used to calculate the first part of the loss tree for conversion.
• Irradiance after bifaciality factor. Here the bifaciality factor has been applied by rescaling the contribution from the back-irradiance using the bifaciality factor. This is used to calculate the effect of the bifaciality factor on the energy output.
• Irradiance after back irradiance mismatch effect. Here the back irradiance is further scaled by the back-irradiance mismatch effect.
• Mismatch shaded irradiance, denoted \(G_{\text{msh}}(j,t)\). This is the irradiance value that is used in the final energy calculation. It is no longer based on the proportion of shading but the specific sub-module shading based on the most shaded cell.