Different glass cover designs for solar stills: A review

Water is the key for all kinds of life, and fresh water is the main resource for life on dryland generally and human beings specially. Transforming salty, saline, and brackish water into potable water is one of the solutions humanities has invented to overcome the lack of water. Solar stills are a simple, cheap tool used for that purpose with the aid of desalination concepts. Many kinds of stills have been invented with many designs and modifications to increase the productivity and efficiency of those stills. However, solar stills mainly consist of the same parts non-freshwater basin, a condensation surface, and the collection of fresh water. The present work focuses on the glass cover shapes, which is also the condensation surface, for simple (having no external additions) passive kinds of stills. Single slope solar stills (SSSS), double slope solar stills (DSSS), V-type solar stills (VSS), pyramid solar stills (PSS), tubular solar stills (TSS), conical solar stills (CoSS), spherical solar stills (SSS), and hemispherical solar stills (HSS) are all presented in detail. Reviews on different designs and factors affecting productivity and efficiency of stills have been observed and the way forward elaborated.