Impact of water cooling on photovoltaic modules performance in Polish climate conditions – a case study

Atmospheric conditions, such as for example ambient temperature, may have the influence on temperature of a photovoltaic (PV) module. The greatest impact is exerted by solar radiation intensity, leading to an increase in the temperature of pho-tovoltaic cells. As the temperature of the module increases, the efficiency and thus the generated power decreases. The cooling systems capable of lowering the temperature of the module, thus improving its efficiency may be promising solu-tion to this problem. This paper presents the results of a study on the effect of water cooling of a photovoltaic module. The experiments were conducted in Poland using the test stand composed of two photovoltaic modules. One module was equipped with a water cooling system at its front surface while the second module was treated as the reference. Thanks to such a test setup design it was possible to study the influence of atmospheric conditions on the change of photovoltaic module temperature, power output and amount of energy generated by the cooled and reference module. Two cooling methods concerning the timing of cooling water flow activation/deactivation were investigated. The first method involved a fixed cooling time and intervals, while the second method adjusted the cooling water flow activation and deactivation time based on the surface temperature of the module. As a result of the conducted research, a maximum decrease of 17.6 K of photovoltaic module temperature and a maximum power increase of ca. 5%, using the cooling system, was achieved. Furthermore, a correlation between cooling efficiency and cloud cover was described, as well as a method for determining cooling water flow. It was found that better cooling results are obtained when employing a cooling activation and deacti-vation method based on temperature dependence.