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•The effect of mounting porous media on thermal behavior of PV panel was experimented.•Three various porous media thicknesses with and without wind flow were tested.•PV temperature drop of 4 to 18˚C were observed for the considered cases.•Energy, exergy and entropy generation in the system were calculated and discussed.•A global comparison between results of this study and the others was presented.

Solar energy is the most accessible renewable energy which takes over the leading position in sustainable electricity generation. Photovoltaic (PV) technology deals with direct transformation of sunlight into electricity. A proved deficiency of this technology is a significant drop in its output power due to temperature increment in PV cells. In this paper, two cooling methods of mounting fins at the back surface of PV cells and an artificial wind stream are applied and experimentally studied. Accordingly, various fin quantities are tested, with and without wind blowing of 2 km/h, and the results were compared with the conventional one. As results, it was shown that wind stream is more effective than fins. So that, the temperature reduction of 14.9 °C was measured when 40 fins mounted with no wind blowing, while in the case of wind blow with no fins the module temperature was reduced 24.4 °C. The mentioned reductions led to 2 and 4.1% enhancements in electrical efficiency, respectively. In a scaling up estimation, at the absence of wind stream, the required number of PV modules for erecting a 10-kW PV power plant is cut by 6.5–13%, when 10–40 fins were used. 24% of the required number of PV modules is saved when an air of 2 km/h is constantly streams regardless of the fins mounted or not. Also, the measured experimental data were compared with some empirical relations, and an excellent agreement was noticed. Furthermore, in an entropy assessment, less entropy generation is calculated for the considered cases.

Conversion of light into electricity is possible by means of photovoltaic (PV) technology. The negative impact of increasing the temperature of PV cells on their output power is one of the most important weaknesses of this technology. In this experimental study, a porous medium integrated with phase change material (PCM) as two passive cooling methods of PV modules are employed and their effects on cooling the PV panel are investigated, either separately or simultaneously. Two thickness values of the aluminum porous medium were mounted at the back side of PV module. The results show that a 2 cm thick porous medium reduces the module temperature by 14.5 °C, while when PCM is added, the temperature drop reaches 21.5 °C compared to a conventional PV module. Moreover, adding PCM, downgrades the rate of temperature rise. Increasing the output power due to the use of PCM and porous media, causes 18.6 % less PV modules to run a 10-kW photovoltaic power plant. The entropy generation of the system was also calculated and 4 % difference between the mentioned cases was calculated. An important concern about the thermal exergy assessment is discussed in details.

Due to the increasing demand for energy in the world and the problems caused by fossil fuels, the use of renewable energy has become the focus of governments. Therefore, the study and use of renewable energy, especially solar energy, is an essential development program for all governments. There are massive efforts to increase the efficiency of photovoltaic (PV) technology which is rapidly developing, in order to decrease the capital cost of a solar power plant. In this paper, two methods for enhancing the efficiency of PV modules are considered: using phase change material (PCM) as coolant and integrating reflectors. The experiments were performed in Dezful, Iran, with very hot summers. The results show that, using reflector boosts the received irradiation by the PV panel, but at the same time, leads to increase the PV module temperature. Therefore, using PCM in order to decrease the temperature is justified. Among different tilt angles of the mirror, 30° presents the best outcomes. Then, this case was tested with one additional mirror on top of the PV module. So, the case of double mirrors was selected and bring about 4.1 % improvement in electrical output, in comparison with the conventional one. As the next stage, this optimum case was repeated by utilizing the PV module with PCM at its back side. 12.5 % enhancement of electrical output and 24 % reduction in entropy generation were calculated, in comparison with the conventional one.