Climate-Specific Thermal Model Coefficients for c-Si and Thin-Film PV Modules

The thermal model coefficients (U
_c
and U
_v
), similar to the thermal loss factors used in PVsyst for various PV technologies specific to a hot climate are presented in this paper. Minitab, a statistics package was used for the analysis of the data. These coefficients were determined by statistically correlating a year-long data for the modules mounted on free-standing arrays of four PV technologies (crystalline silicon, CdTe, CIGS, a-Si) which experienced hot-desert climate conditions. Various statistical approaches were used to analyze the data. Limiting the wind speed in the one hour interval data showed statistically satisfactory patterns in the model adequacy plots. The U
_c
and U
_v
values determined for a-Si module with Tefzel superstrate was higher than the a-Si module with glass superstrate. The lowest U
_c
and U
_v
values were observed for CdTe PV technology. For crystalline PV technology, Uc value of 25.46 W/m
²
·K and U
_v
value of 4.31 W/m
³
·K·s were obtained.