Solar module cooling tech based on perforated fins

A research group at the University of Batna, Algeria, has evaluated the cooling performance of heat sinks with different fin geometries and perforated structures for photovoltaic (PV) applications.

“This work’s combination of geometric optimization of fins and perforations offers new insights into advanced heat sink designs tailored explicitly for solar energy applications,” the researchers explained. “Computational fluid dynamics (CFD) simulations were used to model laminar forced convection and conduction heat transfer, enabling comparison between different fin and perforation configurations and a conventional rectangular heat sink.”

The team investigated four designs: plain rectangular fins (PRF), plain hexagonal fins (PHF), hexagonal fins with rhombus perforations (HFRP), and hexagonal fins with hexagonal perforations (HFHP).

All configurations were modeled as attached to a 165 mm × 65 mm polycrystalline silicon solar cell rated at 6 V/250 mA. Each heat sink consisted of 18 aluminum fins. The PRF design served as the reference case, while PHF used hexagonal fins to increase surface area. The HFRP design incorporated four rhombus-shaped perforations per fin, and the HFHP configuration used four hexagonal perforations per fin.

CFD simulations were conducted at an ambient temperature of 25 C. Air inlet velocities were set at 0.3 m/s, 0.6 m/s, 0.8 m/s, and 1 m/s. Solar irradiance levels of 1,000 W/m², 1,500 W/m², 2,000 W/m², and 2,500 W/m² were applied, corresponding to concentration ratios of 1, 1.5, 2, and 2.5 suns, respectively.

“The HFHP heat sink design effectively reduced the solar cell temperature, achieving a 20.93% decrease at the highest irradiance of 2,500 W/m² compared to the PRF design. Similarly, the HFRP and PHF configurations showed temperature reductions of 17.44% and 7.67%, respectively,” the academics explained. “Electrical efficiency improvements were also recorded, with HFHP increasing efficiency by 0.48% compared to PRF. PHF achieved a 0.30% improvement, while HFRP reached 0.43% at an irradiance level of 1,000 W/m².”

At an air velocity of 1 m/s, the HFHP configuration consistently delivered the best thermal performance, achieving the highest Nusselt number, 62.49% higher than the PRF baseline. HFRP and PHF followed with improvements of 51.65% and 44.32%, respectively.

The simulation also indicated that the additional fan power required for forced convection was negligible compared to the PV cell’s electrical output, preserving more than 97% of generated power for useful output.

“By incorporating shaped perforations, such as hexagonal or rhombus structures, into heat sink fins, heat transfer performance is enhanced, resulting in an overall improvement in the performance evaluation factor (PEF),” the researchers concluded. “These designs will be further evaluated experimentally, including fabrication via CNC machining and testing under real operating conditions.”

The novel technique was presented in “Design and optimization of perforated shaped fin heat sinks for enhanced solar cell cooling,” published in Thermal Science and Engineering Progress. Scientists from Algeria’s University of Batna, Malaysia’s National University, India’s University of Rajasthan, and the United Arab Emirates’ Abu Dhabi University have contributed to the research.