Simultaneous electricity generation and low-energy-intensive water desalination using a hydraulic wind turbine

Current electricity generation using non-renewable energy sources represents 40 % of global CO₂ emissions, alongside the 4 million tons of CO₂/year generated by desalination plants. The need to accelerate the energy transition to decarbonize electricity and freshwater generation has driven the development of functional alternatives. Previous studies have highlighted the advantages of using hydrostatic transmission to transmit power harvested by wind turbines as an alternative to the mechanical drive train. This study experimentally demonstrates the feasibility and benefits of using wind energy to simultaneously generate electricity and produce freshwater through an integrated hydraulic powertrain. The cyber-physical system integrates four main subsystems: a prime mover (an electric motor simulating the wind turbine rotor), a hydrostatic transmission, an electric generator with its load, and a reverse osmosis system. The hydrostatic transmission provides a damping effect on fluctuations induced by wind speed variations up to 5 %, achieving an overall efficiency of 79 % under tested conditions. Specific energy consumption (SEC) for feed salinities ranging from 5 g/L to 40 g/L is between 1.6 kWh/m³ and 6.8 kWh/m³ without an energy recovery device (ERD). Using the ERD reduces SEC by 9 % to 39 %, depending on the brine flow rate to the ERD. The proposed system architecture reduces energy consumption and costs for desalination and energy generation, enabling net-zero CO₂ emissions during freshwater and electricity production.