Enhancing tilted solar still performance by improving evaporation with a cotton wick and condensation with thermoelectric cooling through experimental and economic analysis

Abstract Tilted solar stills are a promising option for sustainable water desalination, but their productivity is limited by low evaporation and condensation efficiencies. This study presents a dual-functional strategy for improving the performance of a modified tilted solar still using a mesh cotton wick to enhance water distribution and continuous surface wetting and a thermoelectric cooling tube to lower the condensing surface temperature and increase the condensation rate, thus increasing the overall system productivity. Tests were conducted in Yekaterinburg, Russia, under identical environmental conditions for both the modified tilted solar still and the conventional still. The results demonstrated a significant improvement in the modified system, with a 40% increase in freshwater production. The maximum daily production was 1.290 L/m2 from the cooling channel and 0.615 L/m2 from the glass cover, compared to 0.805 and 0.555 L/m2 for the conventional system. Thermal efficiency reached 13% versus 9% for the conventional system. Economic analysis confirmed the system's viability, with the cost of distilled water reduced to $0.0296/L, 13.7% lower than the conventional system, while maintaining competitive costs at varying utility rates. These results demonstrate the effectiveness of the wick-thermoelectric cooling integrated approach in providing a low-cost, energy-efficient, scalable solar desalination solution suitable for arid and energy-limited regions.