A Review of the Effect of Reflectors on the Performance of Solar Stills: A Classification Based on the Solar Still Configuration

Solar distillation is one of the simplest and cheapest technologies for producing fresh water from saline or brackish water in remote and arid regions. Nevertheless, the daily productivity of the conventional solar still remains low, which restricts its commercial deployment. Among the numerous augmentation techniques, mirrors and reflectors have attracted wide attention because they are inexpensive, simple to install, and capable of considerably intensifying the solar radiation received by the evaporation zone. This review surveys the recent experimental and theoretical studies that employed internal and/or external reflectors to enhance solar still performance. Unlike previous reviews that classified the literature according to the reflector position, the present work classifies the studies according to the solar still configuration, covering conventional single‐slope, stepped, trays, inclined wick, pyramid, hemispherical, spherical, half‐cylindrical, conical, tubular, coiled, rotating wick belt, and rotating discs solar stills. For each configuration, the design modifications, operating conditions, and the attained gains in productivity and thermal efficiency are presented and compared. The survey reveals that reflectors alone typically raise the distillate yield by about 20%–60%, while their combination with other augmentation tools, such as wick materials, baffles, external condensers, fans, and nano‐enhanced phase change materials, can push the overall enhancement beyond 150%–300% with daily yields exceeding 10 L/m 2 ·day in several configurations. The review is closed by a comprehensive comparison table, the main conclusions, and recommendations for future research. My research demonstrates a strong commitment to advancing the United Nations SDGs (Sustainable Development Goals), particularly Clean Water and Sanitation (SDG 6): and Affordable and Clean Energy (SDG 7).