Performance and applications of inorganic PCMs in solar thermal energy storage systems

The growing demand for sustainable energy has intensified research on solar thermal energy storage (STES), in which inorganic phase change materials (PCMs) have attracted attention for their high latent heat, favorable thermal properties, and cost-effectiveness. This review summarizes the performance and applications of inorganic PCMs in STES systems, with emphasis on thermal conductivity enhancement strategies such as extended surfaces, metal matrices, metal foams, porous structures, and heat pipe integration. The use of inorganic PCMs in direct and indirect solar thermal systems, concentrating solar power, solar cookers, and solar greenhouses is critically evaluated. Performance assessments indicate that inorganic PCMs can significantly enhance energy storage capacity, thermal stability, and overall system efficiency. In addition, life cycle assessment and economic analyses demonstrate their sustainability and economic feasibility. The review also outlines future research directions, thereby highlighting the potential of inorganic PCMs to advance STES technologies and support sustainable energy development.