An experimental approach on employing air flow through a porous medium as coolant of photovoltaic module: Thermodynamics assessment

The global energy crisis has convinced all governments to invest more in the use of renewable and sustainable energy sources. To achieve this goal, solar energy is more attractive due to its accessibility in most parts of the earth. Photovoltaic (PV) modules are used to convert sunlight into electricity. This technology has an important drawback, as the increase in PV cell temperature significantly reduces its electrical efficiency. This article provides a solution to overcome this issue to some extent. As novelty, in this study, the effect of using porous medium and wind stream are investigated separately and simultaneously by an experimental approach. As a variable, three different thicknesses of 0.5, 2 and 4 cm for aluminum porous medium are considered under two conditions of with and without wind blowing at 2 km/h. The results indicate that the proposed cases led to a drop in the module temperature from 3.9 °C to 18.3 °C. From energy point of view, when the 4 cm porous medium is used, 2.7% and 6.6% enhancements are attained in electrical efficiency and output power, respectively. The second law of thermodynamics was also applied and the maximum drop of 8.3% in entropy generation was calculated. Moreover, a correction in calculating the exergy efficiency is offered. The last part of this paper reports a global comparison between the results of this study with those of other similar experimental papers are presented.