Enhanced conventional solar still performance with water unit, vertical wick system, and PCM-Ag nano integration

Solar distillation represents a sustainable solution for freshwater production in water-scarce regions. However, conventional solar stills (CSS) face significant limitations including low productivity rates, substantial heat losses through rear walls, and inefficient utilization of solar radiation. The study integrates three modifications: (1) a water unit (WU) for heat loss reduction, (2) a vertical wick solar still (VWSS) for hot water feeding, and (3) PCM enhanced with silver nanoparticles for thermal storage. The integrated system CSS+WU+VWSS+PCM-Ag was tested against conventional CSS. Results demonstrated that the fully integrated system (CWCSS+WU+VWSS with PCM-Ag) achieved cumulative daily productivity of 13,250 mL/m 2 , representing a 327% improvement over conventional solar stills producing 3,100 mL/m 2 . The modified system also reduced the cost of distilled water from 0.024 $/L to 0.013 $/L. These findings confirm that integrated modifications combining heat loss reduction, hot water feeding, and thermal storage substantially enhance solar still performance while maintaining economic viability. The study recommends further optimization of nano-enhanced PCM configurations and extended testing under varying climatic conditions.