Description of performance degradation of photovoltaic modules using spectral mismatch correction factor under different irradiance levels

Abstract

Outdoor short-circuit current (ISC) of test photovoltaic (PV) modules, i.e., (1) multi-crystalline silicon, (2) heterostructure-with-intrinsic-thin-layer, (3) single-crystalline silicon back-contact, (4) CuInSe2, and (5) CdTe modules, was evaluated using single-crystalline silicon (sc-Si) PV module as PV module irradiance (Irr) sensor (PVMS). PVMS is used to estimate simultaneous Irr and spectral mismatch correction factor (MMPVMS). The measured ISC (ISC-meas) of the test PV modules at outdoor location under various conditions was corrected to the ISC under standard test condition (STC) for the corrected ISC (ISC-corrected) using the MMPVMS and simultaneous Irr, yielding the description of the degradation of the test PV modules for the credibility of their fabrication technology. Moreover, the estimation of ISC-corrected of the test PV modules under different Irr levels was performed. The ISC-corrected with high precision, close to ISC under STC, was obtained under Irr level of ≥0.2 sun, observed by the PVMS. This leads to the increase the investigation opportunity on both sunny day and cloudy day. The ISC-corrected with the highest precision is moreover obtained under Irr level of ≥0.7 sun. The method using the simultaneous Irr and MMPVMS observed by the PVMS could be applicable under the large fluctuation of the Irr levels.