Experimental investigation of the effect of channel-top PV panel systems on panel efficiency and evaporation

Photovoltaic (PV) panel systems are one of the most widely used energy production systems that convert solar energy from renewable energy sources directly into electrical energy. The performance of PV panels is directly related to the change in panel temperatures caused by solar radiation. Especially at high panel temperatures, panel power decreases considerably. One of the methods to reduce or eliminate the effect of this situation is evaporative cooling, which is a water-cooling approach. Evaporative cooling is an important and successful method of air conditioning, especially in summer in dry climate regions. This approach is a very advantageous application due to the heat energy absorbed by the atomized liquid particles during the phase change into vapor phase. In this study, evaporative cooling of a PV panel placed on a channel created on an experimental scale in Van province, which has the characteristics of a hot and arid climate region according to the Köppen climate classification, was investigated. In addition, since access to water resources is limited in hot and arid climate regions, it is aimed to reduce the amount of evaporation in the channel by shading effect by means of PV panels placed on the channel, considering the need to protect existing resources. The current study consists of three stages. In the first stage, the performance of the PV panel system installed on the channel was examined at different angles compared to the equivalent system installed on the ground, while in the second stage, the effect of different panel inclination angles on the performance of equivalent PV panel-channel systems was examined. In the last stage of the study, the effect of channel flow rate on system performance was examined. As a result of the study, it was revealed that the average difference in the efficiency of channel-top PV panel systems compared to the equivalent systems installed on the ground was 1.9% when all tested conditions were taken into account. The highest difference was found to be 2.8% at the 8⁰ panel inclination angle. When the amount of evaporation was examined, it was seen that an average of 4 liters of evaporation occurred. As a result of the second stage experiments examining the effects of different inclination angles on system performance, it was observed that the efficiency of the examined systems increased by an average of 1.5% with the decrease in the panel inclination angle, while the amount of evaporation decreased. In the experiments where the effects of different flow rates in the channel on system performance were examined, which was the last stage of the study, it was observed that the panel efficiency and evaporation amount increased in systems with the same inclination angle as the channel flow rate increased.