Experimental assessment of flat-type photovoltaic module thermal behavior

The electrical performance and reliability of flat-type photovoltaic (PV) modules can be severely affected by elevated cell operating temperature in regions benefiting from high yearly solar irradiation levels, due to elevated ambient temperatures. In this work the potential of active cooling solutions to enhance flat-type PV module electrical performance, consisting of forced air- and water-cooling, is experimentally explored on laboratory-scale prototypes operated indoors under different light source illuminance levels. Forced-air and water-cooling are implemented using a duct-axial fan configuration and chilled water channel, respectively, both attached to the module non-active surface. In both cooling configurations, the cooling fluid directly wets the module non-active surface, thereby eliminating thermal contact resistance. Forced air-cooling is found to improve module peak output power by approximately 10% relative to passive cooling, in an ambient temperature of 21°C. The output power of water-cooled modules increases by 48% using unchilled water at a temperature 21°C, and by 66% and 69% using chilled water at 14°C and 5°C, respectively, relative to passive cooling. The experiments conducted therefore provide an order-of-magnitude assessment of the technical feasibility of different active cooling strategies before characterizing commercial modules under solar irradiation conditions.