Analysis of an innovative water-cooling solution for photovoltaic-thermal systems

The research is focused on realizing a comparative analysis regarding the parameters of an active water-cooling solution for improving the efficiency of monocrystalline silicon photovoltaic (PV) panels. The efficiency of the photovoltaic panels is dependent on the climatic conditions, varying especially with the change of the intensity of the solar radiation and of the operating temperature. The cooling of the photovoltaic panels is a viable solution for both fixed and variable positions of the system. Numerical modelling was carried out on a photovoltaic panel integrated into the façade of a buildings. The water-cooling solution consist in using a water film heat exchanger attached on the backside of the PV panel. The parameters of the heat agent analysed were the temperature, velocity and width of the water film. The optimal water film heat exchanger solution was obtained for a thickness of 3 mm of water film, a velocity of 0.01 m/s and an operating temperature of 20 °C. In this case, the thermal power extracted by the film exchanger reaches values of 140.8 W, with an overall heat exchange coefficient of 48.6 W/m^2.K. During the study, the global heat transfer coefficient and the raise off efficiency is determined for each case.