Energy Rating
A photovoltaic module’s nameplate usually shows the module performance rating at standard test conditions, a.k.a. STC (1000 W/m2 irradiance, 25°C cell temperature, AM1.5). Such values, however, do not necessarily reflect the performance of the module under actual field conditions. But even with ratings at a more realistic field conditions like NOCT/PTC (800/1000 W/m2 irradiance, 20°C ambient temperature, 1m/s wind speed), the determination of performance rating must still take into consideration changing conditions; for example, spectrum change, angle of incidence change, etc.
Energy rating consists of predicting PV module performance under all realistic conditions and selected reference days: hot sunny day, hot cloudy day, cold sunny day, cold cloudy day, and nice day. An IEC Standard that would define a common approach is under development.
ASU-PTL is ready to provide the PV modules Energy Rating service once the Standard is released. For the time being, Energy Rating is part of our R&D activities.
