As many regions enter 2026 under mounting drought pressure, one of the most intriguing experiments in water security is unfolding far from shore, in the cold darkness of the North Sea. Off Norway’s west coast, engineers are preparing a desalination system designed to operate hundreds of meters underwater—turning the ocean’s natural pressure into a key part of the process.
Flocean one and the idea of desalination without the shoreline megaplants
The project is called Flocean One. It is slated to begin operations in 2026 near Mongstad, where its creators plan to deploy a fully submersible desalination unit at roughly 300 to 600 meters below the surface.
Instead of relying on large onshore facilities with extensive intake channels, settling infrastructure, and heavy pump trains, the concept is to place the “plant” where the feedwater already is—and where pressure is naturally high. At those depths, ambient pressure reaches levels that can help drive seawater through reverse osmosis membranes, reducing the need for the massive pumping systems that define conventional coastal desalination.
Why depth matters: pressure helps, and the water is cleaner
Flocean’s approach leans on two advantages that become more pronounced with depth:
Natural pressure replaces part of the energy burden
Traditional desalination on land expends significant energy generating the pressure needed to force seawater through membranes. By operating deep underwater, the system taps into pressure that already exists in the environment, potentially lowering overall electricity demand.
Reduced fouling from deep intake water
There’s also a biological gain. Light fades dramatically by around 300 meters, and at 600 meters conditions are largely dark—meaning far less photosynthesis and typically fewer algae-related issues that complicate surface intakes. Surface systems often battle fouling from plankton, seasonal blooms, sand, microplastics, and organic matter, which pushes up chemical use, filtration requirements, and downtime.
According to early engineering data cited in the source, using deeper water could reduce pre-treatment equipment needs by up to 60% and extend the interval between membrane cleanings.
A modular “capsule” that sends freshwater back to shore
Rather than a single monolithic facility, Flocean One is described as a self-contained subsea “capsule” that descends to operating depth, produces freshwater, and then transfers it to shore through a pipeline.
One standard unit is expected to produce about 1,000 cubic meters of drinking water per day. The article states this level could cover the domestic needs of roughly 37,500 people, assuming moderate consumption and sufficient storage. A single site could host multiple units, scaling output to as much as 50,000 cubic meters per day by adding more capsules over time.
The company’s go-to-market approach is described as Build-Own-Operate, in which Flocean finances, installs and runs the units, then sells the water as a service—potentially reducing the upfront investment burden for municipalities and utilities.
Keys
- Flocean One targets a 2026 launch near Mongstad, Norway, operating at 300–600 meters depth.
- The system aims to use natural deep-ocean pressure to reduce dependence on large onshore pumps.
- Deep water intake may mean less biofouling and fewer algae-related issues, with pre-treatment needs cited as up to 60% lower.
- One capsule is projected at ~1,000 m³/day, with sites scalable up to 50,000 m³/day.
- The project is positioned as a response to growing water stress; the source cites UN estimates that by 2030 global demand could exceed resources by around 40%.
Why desalination is back in focus as water stress rises
The broader backdrop is an intensifying global water squeeze. The source highlights UN estimates suggesting that by 2030 global water demand could outpace available resources by roughly 40%, driven by population growth, expanding irrigated agriculture, industrial usage, and declining aquifers.
Conventional desalination already plays a major role in certain regions, but it has also carried persistent obstacles: energy intensity, heavy capital requirements, and environmental concerns related to brine discharge. Flocean’s subsea approach is presented as a bid to shift those trade-offs, with the source reporting potential energy savings of 30–50% versus typical plants, plus major reductions in coastal land use.
Environmental questions: brine discharge moves offshore and deeper
Environmental scrutiny will remain central. The article notes that Flocean’s concept releases brine in deep water and without added chemicals, a strategy intended to avoid concentrated discharge right off beaches and sensitive nearshore habitats. Researchers continue to debate long-term impacts, but the article suggests that dispersing brine away from fragile coastal ecosystems may reduce local stress compared with nearshore outfalls.
Where the model could travel next
Interest is already growing beyond Norway. The source says TIME included Flocean’s capsule among its best inventions of 2025, and that water-technology firm Xylem has taken a strategic stake to support industrial scale-up. In Norway, the municipality of Alver is planning to connect the first units to its local network.
Ultimately, the larger test will be whether the system can be replicated in water-stressed coastal regions—particularly areas that have deep coastal waters nearby but limited space or public appetite for large shoreline plants.
What to watch as the first units roll out
The promise is significant, but so are the engineering and regulatory questions. Operating subsea equipment for long periods requires proving durability against corrosion, currents and biological growth, while maintaining safe maintenance procedures. Regulators will also want robust monitoring of brine plume behavior, especially around fisheries and migratory routes.
If the early deployments deliver on performance and reliability, underwater desalination could emerge as a new tool for water security—one that expands supply without expanding coastal footprints.
