Enabling Dynamic 3D Windmill Evaporator for Continuous Water Desalination, Localized Point Salt Crystallization and...

Solar steam generation is an eco-friendly desalination method, but salt crystallization within the evaporator workspace decreases system efficiency and lifespan. We report an enabling dynamic 3D windmill evaporator that achieves continuous water desalination, localized point salt crystallization and harvesting. By adjusting the structure of the windmill evaporator and the position of the water transport point, the salt solution transport and backflow pathway can be controlled to produce different salt crystallization behaviors. Salt crystallization localized solely at the evaporator blade edge apex, spatially isolated from the water evaporation surface, ensuring steady steam generation and salt collection. The system maintained high evaporation rates of 2.25 kg m^-2 h^-1 and salt collection rates of 41.2 g m^-2 h^-1 over 420 h at 20 wt.% NaCl solution. Furthermore, the windmill evaporator combined with microgenerators can convert wind energy into electricity, one 3D dynamic system can generate peak voltage of 12 V and evaporation rate of 12.9 kg m^-2 h^-1 in outdoor testing. Finally, this study demonstrated an integrated "desalination-wind electricity-irrigation" system that utilized solar, terrestrial, and wind energy, which brings new hope for future energy conservation and sustainable development.