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Flocean™ taps deep-sea water to halve desalination costs

Published 28 Oct 2023 (updated 7 Feb 2024) · 3 min read

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At a glance

  • Subsea desalinisation system
  • Produces sustainable freshwater from deep-sea water
  • Reduces water costs, energy use and biodiversity loss

Flocean™ is a low-energy, low-cost and eco-friendly subsea desalination system. “We provide affordable freshwater to people, agriculture and industry in the most climate-smart and ocean-friendly way possible,” says Alexander Fuglesang, CEO and co-founder of FSubsea.

Our planet has a serious freshwater deficit. Recent scientific models show that groundwater aquifers are being depleted faster than anticipated. If immediate action is not taken, the global water demand will exceed supply by 40 per cent by 2030.

“Ocean desalinisation is part of the solution, but land-based seawater reverse osmosis (SWRO) is costly and energy intensive. It also discharges toxic brine and chemicals into the ocean, which harms biodiversity,” explains Fuglesang.

Eco-friendly subsea desalination for abundant freshwater

Flocean™ produces freshwater from the deep sea using proven subsea SWRO technology. A patented and proven solution, Flocean is automated, unmanned, modular and easily scalable.

“In essence, the system leverages the natural pressure of predictably clean deep-sea water, combined with proven filtration and pumping technologies, to provide a sustainable source of freshwater from the ocean,” states Fuglesang.

Flocean™ reduces, or even eliminates, the need to pretreat the ocean water before desalination.

This is because water depths below 200 metres receive almost no sunlight, meaning photosynthesis is extremely limited or non-existent. The result is minimal algae and bacteria that can cause biofouling. Deep water also provides consistent water quality and temperature.

In addition, the system uses the ambient hydrostatic pressure at depth, where water is naturally pressurised to 40 to 50 bar. Pumps “suck” freshwater – rather than “push” seawater – through the RO membrane, reducing overall energy consumption by 30 to 50 per cent.

Yellow desalination systems with silver pipes in green seawater
Flocean™ produces freshwater from the deep sea using proven subsea SWRO technology.

Flocean promotes food and water security

Huge energy savings correlate with affordability, cutting the levelised cost of water in half. “Flocean produces the most affordable desalinised water available,” says Fuglesang.

In turn, less expensive desalination helps to secure the global water and food supply. As water consumption rates rise globally, low-income countries in particular require access to affordable water to sustain their growing populations. In addition, Flocean™ uses 95 per cent less land than conventional systems.

Moreover, Flocean™ protects the marine environment with technology that does not need to use chemicals for water pretreatment. Nor is toxic brine dumped into the ocean, as the Flocean brine, or “green concentrate”, has very low salinity and readily disperses in the surrounding waters with no negative impact.

Desalination market to double by 2030

The water desalinisation market is projected to reach USD 33.38 billion in 2030, up from USD 16.84 billion in 2022. Fuglesang foresees Flocean™ becoming a market leader in both industrial and developing countries.

“We are transitioning to become a subsea desalination utility company. We recently shipped our first, patent-protected subsea RO demonstrator plant to the Red Sea area. Our client is one of the world’s largest desalinisation operators,” he says.

“Our business model is to develop plants in areas where there is water stress. Water 400 metres deep must be available within 10 kilometres from shore.”

Flocean builds on FSubsea’s decades of experience with subsea processing. The team has deployed more than 60 subsea pump systems and helped to develop the world’s first subsea water treatment plant. FSubsea has strong partnerships with Siemens Energy and the Saline Water Conversion Corporation (SWCC) of Saudi Arabia.

Yellow desalination unit on the flatbed of a truck surrounding by cheering people
Flocean™ is a low-energy, low-cost and eco-friendly subsea desalination system.

Alexander Fuglesang


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