Spectral Impacts on the Performance of mc-Si and New-Generation CdTe Photovoltaics in the Brazilian Northeast

Spectral distribution of sunlight in the Brazilian Northeast, where most large-scale power plants operate, is bluebiased in comparison with STC. Spectral correction of peak-power and energy predictions becomes important, especially for bluebiased PV technologies like CdTe. Locally-measured ten-minute data and direct methods for spectral impact estimations performed in a 37 MWp plant (5°S, 37°W), showed spectral gains of 3-4% for CdTe and losses of 0-1% for mc-Si. Spectral mismatch analysis using field-measured spectra and IV curves showed that spectral mismatch between mc-Si reference cells and CdTe modules leads to normalized peak-power measurements up to 8% higher than actual STC conditions.