Review of sustainable solar stills: Evaluating design trends and materials life cycle assessment

Freshwater scarcity challenges are increasing due to the shortage of accessible, clean water sources. Solar water distillation is a promising strategy for future development. This study provides a clear understanding by reviewing various solar still types, including the basin solar still (BSS), stepped solar still (SSS), Pyramid solar still (PSS), tubular solar still (TSS), and hemispherical solar still (HSS). The present study provides a clear comparison of various solar still types, considering their designs, performance, materials, costs, and environment impacts. This concept provided a strong tool for decision-makers to select the optimal solar still system to stakeholders’ needs. The significant findings of this study showed that the BSS type accounts for the majority of development effort in literature, has great potential, and is expected to yield additional benefits for further development. Additionally, PSS and TSS have been widely shaped, which offer great sunray accessibility. Most studies have shown that common development techniques are used across various types, such as stepped and multi-tray configurations, wicks, sensible heat storage materials (SHSM), phase change material (PCM), nano-enhanced PCMs, nanofluids, and nanocoating. This study concludes that there is no absolute best solar still type and no absolute best development technique. The suitable solar still type and development technique depends on the nature of the solar water desalination project, the number of consumers, available infrastructure, and the location of the project.