Techno-economic review of solar distillation systems: A closer look at the recent developments for commercialisation

Solar still is a cost-effective device to convert saline water into potable water using cleaner energy to tackle drinking water scarcity and waterborne diseases in rural and remote areas of developing countries and meeting the goal of sustainable development. For many decades, researchers have investigated the most energy-efficient and productive solar still designs to make them commercially viable for industrial and domestic applications. This paper presents the state-of-the-art review of the solar stills, based on techno-economic analysis to investigate the most economical and productive solar still design. From this study, it is observed that in case of the passive solar still, still with trays and internal mirrors is found as the most economical design (CPL = 0.0021 $), and the solar still with Fresnel lens is found to be the most productive design (9.22 L/m(2) per day). Similarly, for active solar still, double-slope, single-basin solar still with flat plate collector is the most economical design (CPL = 0.0078 $). Single-slope, single-basin still connected with two solar-dishes is the most productive design (13.63 L/m(2) per day). For the hybrid and miscellaneous solar still, low concentrating photovoltaic-thermal solar still is the most economical design (CPL = 0.0013 $). Spherical solar still with parabolic reflector is the most productive design (8.25 L/m(2) per day). Comparing all the available solar still designs, it has been found that the low concentrating photovoltaic-thermal solar still is the most economical design. The cascade solar still with flat plate collector is the most productive design of the solar still. It is observed that the parabolic concentrator type tubular solar still with 4.71 L/m(2) per day productivity and 0.033 $/L cost of water production is the optimal solar still design. These identified designs can further be investigated for their commercialisation to achieve faster penetration of solar still technology in society. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study finds that solar stills with trays and internal mirrors are the most economical design for passive solar stills, and solar stills with Fresnel lens are the most productive. In terms of active solar stills, double-slope, single-basin still with flat plate collector is the most economical design, while single-slope, single-basin still connected with two solar-dishes is the most productive design. Low concentrating photovoltaic-thermal solar still is identified as the most economical design for hybrid and miscellaneous solar stills, while spherical solar still with parabolic reflector is the most productive design. These identified designs can further be investigated for their commercialization to achieve faster penetration of solar still technology in society.