Energy, exergy and economic analysis of bioinspired wick solar desalination leaf

Freshwater scarcity and energy constraints have driven the development of low-carbon and efficient solar desalination technologies. To address the salt accumulation and thermal bridge heat loss commonly encountered in conventional wick solar stills, this study proposes a bioinspired leaf-shaped reverse wick solar distiller. The leaf still employs a gravity-driven flowing liquid film to continuously rinse the evaporator surface, thereby mitigating salt crystallization. Meanwhile, a leaf-tip guttation mechanism physically breaks the continuous brine pathway, significantly reducing sensible heat loss and improving thermal efficiency. A thermodynamic theoretical model was established to analyze the heat loss and exergy loss of different components in the distiller, and validated through indoor experiments. The results demonstrate that under 1000 W/m 2 irradiation, the steady-state water production rate and solar thermal efficiency of the leaf distiller reach 0.93 kg/m 2 /h and 60.1 %, respectively. Theoretical calculation results reveal the distribution characteristics of the salinity field and temperature field within the leaf evaporator, as well as the effects of water supply flow rate and salinity on the distiller’s water production performance. Furthermore, outdoor testing in Beijing weather indicates that the designed distiller achieves a daily exergy efficiency of 4.4 %. Economic analysis shows that the water production cost is only $0.019/L, highlighting the novelty and practical potential of the proposed bioinspired reverse-distillation configuration for sustainable freshwater production.