Short-circuit current (I-SC) values of test photovoltaic (PV) modules, i.e., multi-crystalline silicon, heterostructure-with-intrinsic-thin-layer, single-crystalline silicon back-contact, CulnSe(2) (CIS), and CdTe modules, are descripted using multiple regression analysis based on environmental factors (solar irradiance, average photon energy (APE), and module temperature (T-mod)) under several solar irradiance levels. The APE is an index of the solar spectral irradiance distribution. PV module irradiance sensor (PVMS), single-crystalline silicon PV module, is used to investigate simultaneous solar irradiance (IrrT(PVMS)). It is disclosed that I-SC is primarily determined by IrrT(PVMS). Error between the estimated I(SC )and measured I(SC )of test PV modules is investigated. Consequently, precise I(SC )description (low error) is obtained when IrrT(PVMS) is utilized. The more precise description of the I(SC )for CIS and CdTe PV modules, having the bandgap (E-g) different from PVMS, is realized when adding APE environment factor even under low IrrT(PVMS) (>= 0 kW/m(2)), accumulated on both sunny day and cloudy day suggesting the enhancement of investigation opportunity. This is because APE minimizes spectral mismatch error caused by E-g difference between PVMS and test PV module. Moreover, the precision of I-SC description is further increased under enhanced IrrT(PVMS) of >= 0.5 kW/m(2) (on sunny day) due to stable solar irradiance. (C) 2019 Elsevier Ltd. All rights reserved.