Sustainable Desalination Using Wind-Powered MultiStage Vacuum Membrane Distillation

This study introduces a novel wind-powered multistage Vacuum Membrane Distillation (VMD) system designed for sustainable and off-grid freshwater production. The system directly harnesses wind energy to operate essential components, including an electric heater, water pumps, and a control unit under two distinct operational modes: a battery-assisted mode and a real-time wind-driven mode. A water ejector is employed to maintain vacuum conditions passively, eliminating the need for mechanical vacuum pumps. The multi-stage configuration enables thermal energy recovery between stages, significantly enhancing system efficiency. Parametric Analysis revealed that increasing the feed temperature from 40°C to 80°C raised water productivity from 13 kg/ day to 60 kg/ day, a 362% improvement, while the Unit Production Cost (UPC) dropped from 47 S/m3 to 9/m3 (an 80.9% reduction). Additionally, vapor flux increased from approximately 40 kg/m2. h to 181 kg/m2. h under optimal conditions, and permeate pressure was reduced to below 5 kPa with increased pump flow rates. The system demonstrated its strongest economic performance at wind speeds above 6.5 m/s, achieving a minimum UPC of 3.5 S/m3 at 8 m/s, representing a 94% cost reduction compared to operation at 3m/s. This windpowered VMD configuration offers a scalable, energy-efficient, and cost-competitive solution for freshwater production in windrich, remote, or off-grid regions.