PV Module Operating Temperature Model Equivalence and Parameter Translation

Abstract

PV module operating temperature is the second most important factor influencing system yield, after irradiance. A variety of temperature models are used within yield simulation software to predict module operating temperature, which then determines operating efficiency. Four temperature models are frequently used: PVsyst, Faiman, SAPM and SAM NOCT. Although these models are similar, their parameter values are not directly interchangeable. In this work we demonstrate the equivalence or near-equivalence of these four temperature models, and from there we develop equations to convert their parameter values back and forth. This is more than a convenience for users of simulation software. We use this capability, for example, to compare and analyze the typical and default values preset for different model/software combinations. The functions to perform the parameter conversions are made available as open-source software in pvlib-python.