Advanced techniques for augmenting the performance of double-slope solar stills: A comparative study
Mariam E. Murad, Wissam H. Alawee, Hayder A. Dhahad
Abstract
Solar distillation is a cost-effective and environmentally conscious method for obtaining safe drinking water in rural areas. Recent advancements in double-slope solar distillation techniques have focused on improving efficiency through innovative technologies and optimal procedures. This review examines these advancements, aiming to assist scholars in selecting the most suitable methodology for maximizing double-slope solar still production. Modifications such as the use of hollow fins with circular cross-sections have shown promising results. These modifications increase the surface area for solar irradiation absorption, resulting in significant performance improvements. Additionally, the integration of external reflectors has proven effective in enhancing solar still efficiency, increasing the output of distilled water by approximately 82 %. The use of nanofluids, particularly those containing Al2O3, CuO, and TiO2, in passive double-slope solar stills has demonstrated superior thermal energy efficiency compared to base fluids alone. Furthermore, the incorporation of phase change materials (PCM) combined with nanofluids has achieved a peak energy efficiency of 21.56 %. Comparisons between different types of solar stills have shown that double-basin stills produce significantly higher yields, approximately 85 % more, compared to single-basin stills under the same conditions. The implementation of magnets and graphite materials in solar still basins has also proven effective in enhancing efficiency and daily production.