Floating solar stills: A state-of-art review

The growing global scarcity of freshwater, especially in arid and remote regions, has intensified interest in sustainable desalination technologies. Floating solar stills, which operate directly on natural water bodies using solar energy, represent a promising low-cost and off-grid solution for potable water production. This review consolidates recent developments in the design, materials, and operation of floating solar stills, emphasizing their distinctive advantages over conventional land-based systems. The discussion highlights innovative structural concepts such as interfacial evaporation layers, self-floating wicks, and integrated heat recovery configurations that collectively enhance thermal efficiency and freshwater yield. Comparative analysis of recent prototypes reveals significant improvements in evaporation performance and system stability. Persistent challenges—such as salt accumulation, durability under marine conditions, and condensation inefficiencies—are outlined along with future perspectives for scalable, hybrid, and multi-functional floating solar still systems. The review aims to provide a clear roadmap for advancing floating solar still technology toward practical, cost-effective, and sustainable freshwater generation in diverse aquatic environments.