Energy model validation for large-scale photovoltaic systems

PVsyst, a software package developed at the University of Geneva, has become the U.S. industry standard for the simulation of photovoltaic system performance. Despite the widespread use of PVsyst, few validations have been published of the overall model or its components. This research presents the results of detailed validations of the PVsyst model for a large-scale photovoltaic facility located in the U.S. Desert Southwest. Measured plant performance data from one year of operations were compared to simulated values of plane-of-array irradiance, module temperature, and AC energy to assess the accuracy of the Hay and Perez transposition models, the PVsyst module temperature model, and the overall AC energy predictions. On an annual basis, PVsyst performed within the expected margin of measurement error, with greater model uncertainty at shorter time intervals.