Solar stills with thermoelectric cooling: a systematic review of design modifications and performance enhancements

Abstract The present review focuses on the issue of freshwater shortage and growing global request for freshwater, which requires a serious need for original technologies, predominantly solar stills combined to thermoelectric cooling (TEC) to improve desalination competence. The originality of this paper lies in directing a methodical review to analytically inspect design optimizations and performance enhancements in solar stills engaging TEC. Therefore, it goes beyond the prior efforts by resolving the insistent encounters of low productivity and energy inefficiency of conservative systems and discovering the developments made by the combined solar stills and TEC. Similarly, this review emphasizes appraising the helpfulness of different layouts and materials used in these systems through energy and exergy analyses. Important results elucidate that integrated TEC can meaningfully increase freshwater productivity, with reported gains of more than 570%. Effectiveness enhancements are ranged between 11.2 and 76.4%. Furthermore, the incorporation of nanofluids, mainly copper oxide nanoparticles at a 0.08% concentration, has improved freshwater productivity by 81% and exergy efficacy by 112.5%. Further benefits are stated by presenting hybrid designs that incorporate photovoltaic panels, phase change materials (PCMs), and heat pipes. Specifically, the hybrid designs afford the possibility of continuous 24-h operation at reduced freshwater production cost of less than $0.031 per liter. Referring to energy and exergy analyses, it can be assured that TEC can play an essential role in minimizing exergy destruction and maximizing thermal gradients within the system. Thus, it can be determined that TEC-integrated solar stills can offer a wonderful solution for sustainable freshwater production to tackle the progressive water scarcity issue. However, some other barriers are still existed that related to high energy consumption and economic viability that must be resolved. Future investigation should therefore put efforts toward developing optimal designs of TEC-integrated solar stills to ensure a balance between performance, cost, and scalability to enable broader implementation.