Optimizing Solar Collector Performance with Granite and Chrome-Based Selective Coatings: A Characterization Study

Solar collectors play a crucial role in harnessing and utilizing solar energy, making their thermal performance a key factor in the efficiency of solar energy systems. Surface materials and coatings significantly influence heat absorption and retention, impacting overall energy efficiency. This study explores the thermal properties of various surface types, including granite, chrome-based alloys, and high-performance steel (HPS), under controlled conditions. By evaluating their heat absorption and retention characteristics, the study aims to provide insights into the optimal material configurations for enhancing solar collector performance. A series of surface types were evaluated, ranging from solid granite to fully alloyed materials and HPS. Heat retention efficiency and average heat performance were recorded to compare the effectiveness of each surface. Results reveal that solid granite surfaces exhibit a high heat retention efficiency of 92% at an average temperature of 88.1°C, while a fully alloyed surface achieves superior performance with a retention efficiency of 98% and an average heat of 91.2°C. The highest performance was observed with HPS, demonstrating 99% heat retention efficiency and 93.5°C average heat. In contrast, tempered glass and thermal-insulated surfaces yielded significantly lower efficiencies of 74 and 42%, respectively, with corresponding average heat values of 68.5 and 39.3°C. Ambient conditions provided a baseline with minimal heat retention (35%) at an average temperature of 35.2°C.The study highlights the superior performance of alloy-rich surfaces, particularly HPS and fully alloyed configurations, in optimizing thermal efficiency. The findings provide a basis for selecting surface materials and coatings to improve solar collector efficiency. The goal of this study is to contribute to the development of more effective solar energy systems by characterizing the thermal performance of granite and chrome-based selective coatings.