World’s first subsea desalination plant to launch in Norway

Imagine drawing drinking water directly from the ocean without heavy pumps or sprawling land facilities. That vision is becoming a reality in Norway.

Flocean, a Norwegian engineering company, will launch the world's first commercial-scale subsea desalination plant at Mongstad in 2026, a breakthrough that could change how the world accesses freshwater.

The facility, named Flocean One, will initially produce 1,000 cubic metres of potable water daily. It uses reverse osmosis pods placed hundreds of metres below the ocean surface. At such depths, the weight of the water itself pushes seawater through membranes, dramatically cutting the energy needed compared with conventional land-based plants.

Flocean estimates energy savings of 40-50% and claims the system avoids toxic brine discharge while occupying only five per cent of the land footprint typical for traditional plants.

Flocean has tested the technology at its Mongstad site since November 2024, desalinating water from approximately 524 metres below the surface.

The company highlighted that deepwater conditions — stable temperature, salinity, and low bacterial presence — reduce pre-treatment needs and simplify operations.

However, experts cautioned that broad deployment will require overcoming technical and economic challenges. Nidal Hilal from New York University Abu Dhabi noted that membrane maintenance and costs remain significant, though advances in electrically conductive and sustainable membranes could improve efficiency.

Flocean One represents a first step toward a modular and scalable approach to freshwater production. With strong support from Norwegian authorities and a coalition of industrial partners, subsea desalination could offer a resilient, energy-efficient solution to meet rising global water demand.

TIME magazine has named the project as one of the Best Inventions of 2025.