Using physical parameters in predicting energy gain of CIGS PV modules

In previous works [1, 2] it was researched that the equivalent double diode model - DEM is appropriate to model Cu(In_xGa_1-x)Se₂ (CIGS) photovoltaic (PV) modules. It was investigated with large amount of data (including current - voltage curves) collected during long-term monitoring of PV systems. Current work concentrates on applying physical parameters to model 2 of 5 DEM parameters: diffusion IS₁ and recombination IS₂ related components of dark diode saturation current. Modeled ISI and IS₂ values replace previously approximated DEM parameters and are used to predict measured I-V curves in order to determine electrical parameters of the PV modules. The parameters are used to predict energy gain in natural working conditions. Results of modeling are presented and compared with measured data.