Heat Loss in PV Modules

Source: Sustainable Energy Research – SpringerOpen
The Operating Temperature of Photovoltaic (PV) Modules

Heat Conduction

Conductive heat losses in PV modules occur due to thermal gradients between the module and surrounding materials. The ability to transfer heat is determined by the thermal resistance and material configuration of the solar cells. Conductive heat flow is similar to electrical current flow, where temperature difference drives the heat flow. The relationship between heat transfer and temperature is described by specific equations.

Convection

Convective heat transfer in PV modules happens when heat is carried away by the movement of air across the module’s surface. The heat transfer through convection is influenced by factors such as the area of contact, the convection heat transfer coefficient, and the temperature difference between materials. Calculating the convection heat transfer coefficient is usually done experimentally for a given system and conditions.

Radiation

Radiative heat transfer is another way PV modules release heat to the environment. Objects emit radiation based on their temperature. The power density emitted by a blackbody can be calculated using specific equations. In the case of PV modules, the emissivity of the material must be considered to adjust for non-ideal blackbody behavior. The net heat lost due to radiation is determined by the difference between the heat emitted from the surroundings to the module and the heat emitted from the module to the surroundings.

Source: PVsyst