A detailed review on various aspects of inverted solar still desalination systems proposed for clean water production

Rapid degradation of quality and quantity of the available limited fresh water reserves has forced nations around the globe to search for alternate fresh water sources. This has led to the development of various desalination technologies to generate potable water from abundantly available sea and brackish water. Desalination sector has undergone various upgradations to meet the rising fresh water demand in a sustainable way. One such upgradation is the utilization of solar energy as an energy source. High cost and associated environmental impacts with large-scale desalination systems have shifted the focus of researchers towards research and development of various small-scale efficient solar stills for cheap potable water production in rural, remote, arid, and coastal locations. In this review article, various configurations of a non-conventional solar still, namely inverted solar still, have been reviewed extensively by highlighting its classifications, design aspects, working principle, features, and economics. Moreover, the role of inverted solar still’s evaporating and condensing surface characteristics and thermal properties on its distillate productivity has also been discussed. Inverted absorber multi-basin solar still and inverted multi-effect diffusion solar still configurations are highly productive. Economics of inverted solar still is better than other conventional solar still configurations and conventional reverse osmosis plant of few m3/day capacity. This review article will facilitate researchers to select appropriate inverted solar still configuration for further performance improvement and commercialization. The scope for future research works on inverted solar still has also been listed.