Aluminum Foil Reduces Temperature of Double-Glass PV Modules by as Much as 6°C

A team of researchers led by scientists from China's Nanchang University has proposed adding aluminum (Al) foil inside photovoltaic modules to improve their in-plane thermal conductivity and cool them from the inside. The team proposed two methods of placing the aluminum foils, fabricated them, and compared them to a reference device without AI.

“Passive cooling methods, such as phase change cooling and radiative cooling, dissipate heat from the surface of the PV module with little consideration of in-plane heat transfer close to the solar cell,” the scholar said. “In this paper, we introduce aluminum foil with good thermal conductivity into the PV module structure to dissipate heat from the lateral direction while improving the in-plane temperature uniformity of the PV module.”

The first structural model placed a 0.5 mm thick Al foil between the c-Si solar cell and the vinyl acetate (EVA) layer (CAE), while in the second structural model it was placed between the EVA and the glass layer (EAG). A reference module was also created without the aluminum foil layer. The area of all layers was 250 mm to 250 mm, except for the cell, which measured 156 mm to 156 mm. A thermocouple was attached to the back of each module.

Standard PV modules, EAG, and CAE PV panels were placed simultaneously on a stand, which was tilted 30° toward the south. "Outdoor experiments were conducted in February 2024 on the roof of the Materials Building at SCU. Temperature data were collected by temperature loggers at 1-minute intervals."

In the cloudy test setup, the maximum and average cooling effects of the EAG PV modules compared to the reference were 2.9°C and 1.9°C, respectively.The corresponding cooling effects of the CAE PV modules were 2.3°C and 1.5°C, respectively. On sunny days, the maximum cooling effect was 4.7 C and the average cooling effect was 2.4 C for EAG PV; 3.6 C and 1.5 C for CAE.

To evaluate the effect of aluminum foil on the thermal uniformity within the face of the PV micro-module, an additional thermocouple was added at the edge of each module. The maximum temperature difference was 20°C at the reference module, 14.6°C at the EAG, and 14.9°C at the CAE.

Based on these results, the team performed finite element simulations of the modules, which showed deviations from the experimental setup but were “generally consistent.” The team focused on the EAG structure, which is much more effective and electrically safe, and they simulated a commercial module. It uses PERC cells with a 6 × 10 structure. They found, “The results show that the Al foil reduces the temperature difference across the PV module by 6.170 degrees Celsius and improves the temperature uniformity compared to the reference PV module.”

The results of the study were published in the journal Next Energy in the article “Temperature reduction of single-sided double-glass photovoltaic modules by improving in-plane thermal conductivity.” Researchers from Nanchang University in China and Chinese PV manufacturer Jiangxi Rainbow PV conducted the study.