Experimental evaluation of a solar water heating system integrating thermal mass and phase change material for enhanced efficiency in residential applications

Abstract This study introduces a novel solar water heating system for residential applications, integrating an evacuated tube solar collector with a combined thermal mass storage unit using water and phase change material (PCM). The system optimizes energy retention and heat delivery by leveraging PCM’s high latent heat storage capacity and water’s specific heat. Experimental results demonstrated significant performance improvements, with PCM-based storage achieving temperatures up to 85°C at high sunlight intensity (1200 W/m2), surpassing water-only systems by 13%. The system maintained consistent water temperatures (33°C–58°C) despite low sunlight intensities. This innovation enhances system efficiency, adaptability, and sustainability under variable sunlight.