Effects of cooling on performance of photovoltaic/thermal (PV/T) solar panels: A comprehensive review

The most important energy source for the world is the sun. Energy from the sun named solar energy can be converted to electricity using photovoltaic/thermal (PV/T) solar panels. PV/T solar panel energy conversion efficiency is low due to several reasons. One of the most important reasons is the increase in the temperature of the panels. This increase in temperature decreases the efficiency of the panels. To improve the efficiency, panels should be cooled using a cooling technique. In this comprehensive review study, cooling techniques used in the previous studies are analyzed and the decrease in temperature and enhancement in electrical efficiency are presented. In this study also, passive and active cooling techniques which were examined in the previous theoretical and experimental studies are investigated separately. Within the scope of this review study, which examines cooling of solar panels, a total of 208 publications, 14 of which are books, 34 of which are review articles, and 160 of which are research articles, have been reviewed. Also, most of the studies are experimental, the most preferred panel type is poly-crystalline panel, the most used cooling techniques are active cooling techniques, and the most preferred fluid is water as coolant. On the other hand, 39 of the research articles is theoretical, 91 is experimental, and 30 is both theoretical and experimental. In this review, a table was prepared containing type of PV/T, cooling method, fluid or material used in cooling, decrease in average temperature due to cooling and increase in electrical efficiency from reviewed studies. A detailed statistical analysis was per-formed benefiting this table named Table 1. As a result, it was seen that panel operation temperature could be reduced by as much as 49.2 degrees C and efficiency of the panel could be improved by as much as 47.67 % as shown in Fig. 9 -Fig. 24.