Subsea desalination

Subsea desalination is a method of producing freshwater from seawater using desalination equipment placed underwater, often at significant ocean depths. Instead of pumping large volumes of seawater to an onshore plant, subsea systems can use natural hydrostatic pressure from deep water to help drive reverse osmosis membranes, reducing the energy normally needed for pressurization. The approach may also reduce coastal infrastructure needs and allow brine to disperse offshore, although environmental impacts, maintenance, permitting and long-term performance must still be assessed. Subsea desalination is being explored as a lower-energy option for water-stressed coastal regions seeking more resilient freshwater supplies.