Key pathways for efficient solar thermal desalination

Along with the decline of fresh water resources, desalination has grown in an increasingly significant technology. The utilization of sustainable energy sources, especially solar energy, has tremendous advantages over traditional energy sources for desalination. Solar thermal desalination forms part of the predominant approaches to solar-driven desalination. However, it encounters significant challenges associated with elevated system costs and diminished efficiency in its traditional configuration. This review critically assesses these limitations and delves into the underlying factors contributing to the substantial expenses and reduced effectiveness of such systems. To address these issues and enhance the economic viability of solar thermal desalination while achieving high efficiency, seven key pathways are comprehensively summarized: concentrate solar radiation to collect heat and couple the collector with the distiller, interfacial evaporation, multi-mode hybrid, multi-stage approach to utilize latent heat, multipurpose, directly combine with users and artificial intelligence. The principles and design concepts of each pathway are presented in detail. Comprehensive coverage is given to research methodologies, as well as the limitations, advantages, disadvantages, and future directions unique to each pathway, drawing upon the characteristics of existing research. Based on these pathways, solar thermal desalination will overcome traditional challenges, undergo gradual commercialization, and emerge as a viable option for desalination in the future. Furthermore, this review provides a brief analysis of the energy and environmental aspects, emphasizing the significant importance of balancing efficient development with environmental preservation.