Direct wind-powered vertical axis brackish water desalination system

Abstract

The supply of freshwater based on wind-powered desalination is technically feasible, but energetic losses associated with conventional systems necessitate new approaches. This study explores a direct wind-powered desalination (D-WPD) system using a small-scale vertical axis wind turbine (VAWT) for reverse osmosis via a high-pressure pump without electricity generation or a system controller. A comprehensive parametric study examined the effects of feed water salinity, loading, and wind speed on the system's performance, demonstrating high efficiency under various operating conditions. A stand-alone system demonstrated operation at effectively constant system efficiency, approximately 13.5 %, and low specific energy consumption for a wide range of wind speeds and salinities. Despite the turbine's small projected area of 0.8 m2, the D-WPD system yielded a daily permeate production of up to 0.6 m3/day at an average wind speed of 6 m/s. The D-WPD system surpassed previous wind-powered desalination studies in terms of specific energy consumption, relative efficiency, and relative desalination capacity. Leveraging the environmental benefits of the slow-spinning VAWT, this D-WPD offers a cost-effective off-grid solution for small-scale desalination.