Outdoor testing of PV module temperature and performance under different mounting and operational conditions

Outdoor performance of photovoltaic (PV) modules primarily depends on the instantaneous plane-of-array irradiance (Gpoa) and PV module temperature (Tpv). Tpv can be estimated from the ambient temperature (Tamb) and the Gpoa as Tpv=Tamb+kTGpoa. The coefficient kT depends strongly on the way the PV module is mounted (open rack, ventilated or unventilated roof mounting, etc.), wind speed and also on the module type. In the presented paper, open rack mounted and unventilated roof integrated cases of PV module installation are experimentally and theoretically examined. Linear relationship with kT is upgraded with a nonlinear one based on the energy balance model and measured data. Nevertheless, Tpv is also affected by the module’s regime of operation. The Tpv dependency on different regime of operation (open-circuit and maximum power point tracking) for two types of PV modules in two regimes is reported. Differences are discussed in light of energy balance equation within thermal management, where impact of the PV module conversion efficiency on Tpv is also shown.