An experimental assessment of five distinct solar distiller designs' thermo-economic performance

This study evaluates five solar still (SS) designs—spherical, cylindrical, pyramid, conventional, and double-slope—to determine the most efficient configuration for freshwater production at a specific test location. In initial testing, the unmodified SS designs were compared to a traditional distiller. Modifications were then made to the spherical SS by adding external reflectors, followed by integrating phase change materials (PCM) with silver nanomaterials. The final configuration tested included the spherical SS with reflectors, fans, and external condensers. Results showed substantial productivity increases over the conventional solar still (CSS), with production enhancements of 115 %, 105 %, 68 %, and 31 % for the spherical, cylindrical, pyramid, and double-slope SS designs, respectively. The spherical SS with optimized Nano-PCM and reflectors achieved a 230 % increase over CSS (10,420 kg/m² vs. 3150 kg/m²). The best-performing configuration, combining a fan, condenser, and reflectors, yielded a 253 % improvement, with daily outputs of 11.3 kg/m² compared to 3.2 kg/m² for CSS. Economic analysis revealed that the optimized spherical SS configuration reduced the cost of freshwater production to 0.01 $/kg, significantly lower than the conventional SS cost of 0.024 $/kg.