Utilization of spectral mismatch correction factor for estimation of precise outdoor performance under different average photon energies

Abstract

Outdoor performance of test photovoltaic (PV) modules, especially short circuit current (ISC), is corrected to standard test conditions (STC) utilizing sc-Si PV module as PV module irradiance sensor (PVMS). In this contribution, average photon energy (APE) can be used as an index of solar spectral irradiance. The CdTe PV module was used as a test PV module since its spectrum response is significantly different from that of the PVMS to investigate an effect of spectral mismatch. The median of the error between ISC corrected to STC (ISC-correction) of CdTe PV module using PVMS and its ISC under STC is the highest at 2.64% under APE from 1.75 to 2.15 eV because of the spectral mismatch between PVMS and test PV module. On the other hand, the median of the error is obviously reduced to 0.89%, when ISC-correction was estimated using PVMS and spectral mismatch correction factor under APE from 1.75 to 2.15 eV. The lowest median of 0.54% for the error is furthermore realized under APE in a range of 1.83–1.95 eV, where spectral irradiance mostly indexed by the APE range from 1.83 to 1.95 eV (83% of all spectral irradiance) is frequently occurred at the outdoor installation site.