This paper presents a numerical model regarding the passive cooling of PV panels through perforated and non-perforated heat sinks. A typical PV panel was studied in a fixed position, tilted at 45 degrees from the horizontal with the wind direction towards its backside. A challenging approach was used in order to calibrate the base case of the numerical model according to the NOCT conditions. Further validation of the accuracy of the numerical simulation consisted of a comparison between the results obtained for the base case, or heat sink, with horizontal non-perforated fins and the experiments presented in the literature. Six types of heat sink attached to the backside of the PV panel were numerically studied. The analyzed configurations focused on heat sinks with both perforated and non-perforated fins that were distributed horizontally and vertically. The CFD simulation was also conducted by modeling the air volume around the PV panel in real wind conditions. The main output parameters were the average temperature and the convective heat transfer coefficient on the front and back of the PV panel. The most important effect of cooling was achieved in low wind conditions and high levels of solar radiation. For v_air = 1 m/s, G = 1000 W/m² and ambient temperature t_air = 35 °C, the percentage of maximum power production achieved 83.33% for the base case, while in the best cooling scenario it reached 88.74%, assuring a rise in the power production of 6.49%.

The negative effect of the operating temperature on the functioning of photovoltaic panels has become a significant issue in the actual energetic context and has been studied intensively during the last decade. The very high operating temperatures of the photovoltaic panels, even for lower levels of solar radiation, determine a drop in the open-circuit voltage, with consequences over the electrical power generated and PV-conversion efficiency. The temperature effect over the efficiency of monocrystalline and polycrystalline photovoltaic panels by using a double-climatic chamber and a solar simulation device was studied experimentally for two photovoltaic panels, one monocrystalline and another polycrystalline, with the same nominal power of 30 Wp. The double-climatic chamber used is composed of two separate rooms, a cold and a hot one, while the PV panel is placed as a barrier between them. The study is focused on establishing the effect of raising the temperature of PV panels over electrical parameters: voltage, current, and power produced and for efficiency and fill factor to promote sustainable energy consumption. The findings highlight the positive impact of cooling on enhancing system efficiency, with the primary focus on quantifying its overall performance. The operating temperature is controlled by the flow of air on the backside of the PV panel inside the cold room. The level of radiation studied corresponds to a vertical integration of PV panels in building façades. The coefficient of the mean variation of the efficiency with the photovoltaic panels’ temperature was −0.52%/°C; for voltage, −0.48%/°C, and for current, +0.10%/°C.

The numerical modeling of the effect of wind direction and velocity over the air cooling of PV panels with heat sinks is realized. During the study, a random PV panel with typical characteristics was analyzed for three different wind directions—towards its back, towards its front and from the side. The analysis was realized on a fixed PV panel, oriented to the south, with an inclination of 45 degrees from the horizontal position. The accuracy of the numerical simulation was achieved by comparison with the experimental studies presented in the literature and by comparing the NOCT conditions. The numerical study is focused on different types of heat sinks attached to a typical PV panel. The fins were distributed both horizontally and vertically. A challenging task consisted in simulation of the real wind conditions around the PV panel by taking into account the entire air domain. The simulations were realized for air velocity v_air from 1 m/s to 5 m/s, solar radiation of G = 1000 W/m² and ambient temperature t_air = 35 °C. The output parameters analyzed were the average temperature of PV panels and their power production. Although the lowest temperatures were achieved for the back wind, the cooling effect was more intense for the side wind. The other direction studied also determined the cooling of PV panels. The passive cooling solutions analyzed introduced a rise of maximum power production between 1.85% and 7.71% above the base case, depending on the wind direction and velocity.

The negative effect of the operating temperature over the functioning of photovoltaic panels has become a significant issue in actual energetic context, being studied intensively during last decade. The very high operating temperatures of the photovoltaic panels, even for lower levels of solar radiation, determines a drop of the open circuit voltage, with consequences over the electrical power generated and photovoltaic conversion efficiency. The aim of the study is to investigate experimentally the temperature effect over the efficiency of monocrystalline and polycrystalline photovoltaic panels by using a double climatic chamber and a solar simulation device. Within the experimental program were analyzed two photovoltaic panels, one monocrystalline and another polycrystalline, with the same nominal power of 30 Wp. The double climatic chamber used is composed of two separate rooms, the cold and hot one, while the PV panel is placed as a barrier between them. The study is focused on establishing the effect of raising the temperature of PV panel over electrical parameters: voltage, current and power produced and for efficiency and fill factor. The operating temperature is controlled by the flowing of air on the backside of the PV panel inside the cold room. The simulation of solar radiation was performed by using an equipment compatible with the dimensions and characteristics of the climatic chamber. The level of radiation studied corresponds to a vertical integration of PV panels in building facades. The coefficient of the mean variation of the efficiency with photovoltaic panels’ temperature was -0.52 %/°C, for voltage -0.48 %/°C and for current +0.10 %/°C.