Comparison of PV Cell Temperature Estimation by Different Thermal Power Exchange Calculation Methods

A steady-state thermal model for calculate the temperature of a photovoltaic (PV) module has been developed for outdoor installation such as ground-mounted systems. The PV temperature is influenced by environmental variables such as: irradiance ambient temperature, intensity and direction of the wind, module design, orientation and mounting structure. As well as it is influenced by electrical parameters. In literature some single layer thermal balance consider only an overall heat transfer coefficient as a function of wind speed, neglecting the radiative thermal flux. In this paper, five thermal balance are compared and it is shown that the radiative term cannot be neglected, otherwise the PV temperature could be overestimated for low solar radiation intensity and it could be underestimated for high solar radiation intensity. For this reason, the percentage contribution of the heat exchanges, normalized as function of normal incoming solar radiation, are evaluated for wind speed within 1 m/s (natural convection)