A review on various designs for performance improvement of passive solar stills for remote areas

Potable water scarcity is one of the major issues that has been affecting millions of lives. It became serious in underprivileged remote communities that are unable to afford conventional water supply and treatment systems. Passive solar desalination systems as a cost-effective option for water supply are becoming more feasible in remote areas. However, low water yield and poor reliability are the main deficiencies that need improvement. This article reviews recent studies conducted on performance improvement and water cost reduction of passive solar stills associated with new designs and modifications appropriate for remote areas to identify the most effective designs. The individual effect of each component's design on performance parameters (water yield, thermal efficiency, and unit water cost) has been reported and discussed. The design specifications and outcomes of studies were reviewed and presented in tables to give a broad view of activities in the area, and to provide future studies with data for validation purposes. This article shows knowledge gaps and opportunities for future research through a distinct classification of studies to shape a clear roadmap on the development of passive solar stills. The most effective designs of components with respect to their application in remote or disaster-stricken areas with no access to power infrastructure were determined. In addition, issues around the structural design complexity and operational reliability associated with new designs were presented.