A study on the passive cooling performance of photovoltaic modules based on novel composite spoiler fins

Elevated operating temperatures in photovoltaic modules reduce their photovoltaic conversion efficiency and output power. Addressing the limitations of traditional passive cooling fins, which rely on a single enhancement mechanism and have limited heat dissipation capacity, this paper proposes a novel composite turbulent fin structure that integrates branching, curved surfaces, and airfoil characteristics. This structure increases the heat transfer area through an outwardly convex curved surface and utilises staggered constriction channels to induce airflow acceleration, wake recirculation, and thermal boundary layer disruption, thereby enhancing natural convection and radiative heat dissipation on the rear surface of the module. CFD methods were employed to optimize various fin configurations and key geometric parameters, and outdoor experiments were conducted to validate the thermoelectric performance of the optimized configurations. The results show that, under an irradiance of 1000 W/m 2 , the equivalent total heat transfer coefficient of the final staggered fin structure increased from 11.56 W/(m 2 ·K) in the reference group to 34.01 W/(m 2 ·K), whilst the equivalent convective heat transfer coefficient increased from 4.47 W/(m 2 ·K) to 26.54 W/(m 2 ·K). Taking into account both thermal performance and engineering feasibility, a locally optimized parameter set was determined as: flow channel spacing a-b = 19–47 mm, fin height H = 90 mm, outer surface camber height h = 18 mm, lateral spacing Sh = 140 mm, and longitudinal spacing Sv = 150 mm. Outdoor testing demonstrated that the experimental group consistently maintained lower temperatures than the reference group under conditions such as sunny, cloudy, and sunny-to-light-rain weather, with a maximum temperature difference of up to 10.1 °C; output power remained superior during the primary power generation periods. The research results validate the effectiveness of these composite turbulent fins for passive cooling in photovoltaic modules.