The study investigates the performance enhancement of a conical solar distillation system by incorporating different energy storage materials, including glass balls, stainless steel balls, sandstones, and black gravel. These materials were analyzed based on their ability to improve energy and exergy efficiencies. The experimental setup involved using identical sizes (∅ 1.5 cm) of these materials to maximize water evaporation and distillate yield. The key novelty lies in the comparative analysis of these energy storage materials under similar environmental conditions, offering insights into their thermophysical properties and overall system performance. Stainless steel balls demonstrated the highest energy efficiency, reaching 54.06%, with an exergy efficiency of 3.93%, and the highest water productivity of 9.45 L/m²/day. The study’s findings emphasize that stainless steel balls are the most effective energy storage material in a conical solar still, significantly improving water yield and system efficiency. The research presents a practical solution for cost-effective and energy-efficient solar desalination, addressing the global challenge of freshwater scarcity. Future work should explore the integration of advanced materials and hybrid systems to further optimize solar distillation processes.