Thermal modeling accuracy of hourly averaged data for large free Field Cadmium telluride PV arrays

Evaluating the accuracy of the PVsyst thermal model for large scale free-field thin film photovoltaic installations (> 1MW) using measured module temperatures from 4 PV systems reveals that the default thermal parameters within PVsyst over-estimate the cell temperature of the First Solar Cadmium Telluride thin film modules by 3–5 degrees Celsius. This results in a slight conservatism in the energy predicted for First Solar's utility scale projects. A more accurate representation of module temperature can be achieved by using a thermal loss coefficient of U
c
= 30.7 rather than the PVsyst default of U
c
= 29.0 which results in an increase in predicted DC energy of 0.22% to 0.32% on an annual basis.