Optimization and benchmarking of fin geometries for enhanced passive cooling in renewable energy systems toward achieving SDG 7

Effective heat dissipation is essential for the performance and reliability of thermal systems. This aspect is essential particularly in renewable energy applications where passive cooling strategies are necessary to reduce overheating. Prior study has focused on optimizing fin parameters, such as height, spacing, and configuration. This study addresses the lack of systematic comparisons among annular, rectangular, and hexagonal fin geometries with identical surface areas and differing thicknesses under natural convection. The results show that the annular fin provides the best overall performance at the optimum thickness and maintains higher heat transfer coefficients for thicknesses of 2-4 mm. At a thickness of 2 mm, the maximum convective heat transfer coefficient is 15.4 W/m2 K, and the minimum average temperature is 391.52 K. The heat transfer coefficient of annular fins is 8.76% and 10.58% better than rectangular (14.05 W/m2 K) and hexagonal (13.77 W/m2 K) fins, respectively. Thicknesses greater than 2 mm result in diminishing returns due to higher thermal resistance and modified boundary layer dynamics. In this study a conceptual framework has been developed to connect CFD insights to renewable energy uses, such as concentrated solar power (CSP) receivers, solar thermal collectors, PV/T hybrids, wind-aided installations, and off-grid microgrids. The benchmarking of models indicates that it aligns with recent studies and confirms the model's applicability to real-world renewable energy. These findings provide a foundation for advanced materials and sustainable thermal energy management, with implications for academia, industry, and global sustainability goals.