Underwater Desalination Plant to Halve Energy Use

In a groundbreaking development for water technology, Norwegian startup Flocean has announced plans to launch the world’s first commercial underwater desalination plant in 2026. Located at Mongstad on Norway’s west coast, this innovative facility promises to revolutionize how we convert seawater to freshwater by harnessing the natural power of ocean pressure.

The Global Water Crisis: A Growing Challenge

As the world’s population continues to grow and climate change intensifies, access to clean freshwater has become one of humanity’s most pressing challenges. According to the United Nations World Water Development Report, approximately 4 billion people—half of the world’s population—experience severe water scarcity for at least part of the year. Twenty-five countries, housing one-quarter of the global population, face “extremely high” water stress annually.

Desalination has emerged as a crucial technology in addressing water scarcity, particularly in coastal regions. However, traditional desalination methods, especially reverse osmosis (RO), are energy-intensive, typically consuming between 3-4 kWh of energy per cubic meter of freshwater produced. This energy demand not only drives up costs but also increases greenhouse gas emissions, creating a sustainability paradox for a technology meant to solve environmental challenges.

Flocean’s Deep Water Innovation

Flocean’s solution takes a radically different approach by moving the desalination process from land-based facilities to the depths of the ocean. The company’s proprietary technology, called “Flocean Deep,” deploys deep water reverse osmosis systems 400-600 meters below the ocean surface where natural pressure can do much of the work.

How Ocean Pressure Powers Desalination

The concept is elegantly simple yet profoundly innovative. Traditional reverse osmosis systems require high-pressure pumps to force seawater through semi-permeable membranes that filter out salt and other impurities. Flocean’s approach leverages the immense natural pressure found at ocean depths to eliminate this energy-intensive step.

At depths of 400-600 meters, the hydrostatic pressure is sufficient to drive the reverse osmosis process without any mechanical pumping. As noted by Erik Kobayashi-Solomon in Forbes, “At depths of 300-600 meters, the sweet spot for Flocean facilities, the ambient water pressure is so great that seawater can be forced through reverse osmosis membranes with minimal additional energy input.”

This natural pressure utilization allows Flocean to achieve between 30-50% energy savings compared to conventional systems, according to validation by DNV, a leading global certification body. The company’s approach has been validated through real-world conditions with the launch of the Flocean Zero project in November 2024.

Environmental Advantages

Beyond energy efficiency, Flocean’s technology offers significant environmental benefits. Traditional desalination plants produce highly concentrated brine as a byproduct, which can harm marine ecosystems when discharged back into the ocean. Flocean’s system addresses this challenge by producing chemical-free brine that matches the salinity of the surrounding ocean.

As detailed in a study published in ScienceDirect, “Access to high-quality, high-pressure feed water allows for chemical-free pre-treatment and low recovery operation without significant impact on the cost of water. The result is not only an energy-efficient system, but also a chemical-free brine that matches the salinity of the surrounding ocean.”

The technology also reduces the need for extensive onshore infrastructure, eliminating exposure to security and geopolitical risks that can affect land-based facilities. This decentralized approach could prove particularly valuable for regions with unstable political environments or limited space for large infrastructure projects.

The Mongstad Facility: A Strategic Location

The world’s first commercial subsea desalination plant will be located at Mongstad, Norway’s largest offshore supply base and a key industrial hub on the country’s west coast. This location offers several strategic advantages:

Existing maritime infrastructure that can support the deployment and maintenance of underwater systems
Proximity to the Norwegian continental shelf and major offshore installations
A skilled workforce experienced in offshore operations
Supportive regulatory environment for innovative water technologies

Mongstad’s industrial infrastructure, including Equinor’s refinery and extensive logistics capabilities, provides an ideal testing ground for this pioneering technology. The location handles thousands of ship calls each year and extensive activity related to loading, unloading, and storage for offshore installations, making it well-equipped to support the operational requirements of an underwater desalination facility.

The facility, called “Flocean One,” will initially produce 1,000 cubic meters of freshwater per day. However, the modular system can be scaled up to 50,000 m³/day for municipal, industrial, and agricultural use across more than 90 water-stressed coastal markets.

Recognition and Investment

Flocean’s innovative approach has garnered significant recognition in the technology community. The company was named one of TIME magazine’s Best Inventions of 2025, the only desalination solution to make the prestigious list. This recognition highlights the potential impact of subsea desalination in addressing global water challenges.

To scale its sustainable desalination technology, Flocean has secured US$22.5 million in Series A funding, with global water technology leader Xylem as a strategic investor. This investment will be crucial for expanding production capabilities and refining the technology for broader deployment.

Implications for Global Water Security

If successful, Flocean’s underwater desalination technology could have far-reaching implications for global water security. As noted in the World Economic Forum’s Global Risks Report 2025, water crises remain among the top global risks in terms of likelihood and impact. Innovations that make desalination more energy-efficient and environmentally sustainable could significantly expand access to clean water for billions of people.

The technology could be particularly valuable for developing nations and remote coastal communities that currently lack the infrastructure or resources for traditional desalination plants. By reducing both energy requirements and capital investment, underwater desalination might finally make large-scale seawater conversion economically viable for a broader range of users.

In fact, Flocean claims that its approach requires approximately 10 times less capital investment per unit of capacity compared to traditional desalination systems. As noted in LinkedIn posts by the company, “The cost of water is broken—and traditional desal won’t fix it. Flocean’s subsea desal system, by contrast, is targeting ~$28M for 10M liters/day. That’s 10× less per unit of capacity.”

Looking Ahead to 2026

As the 2026 launch approaches, the world will be watching closely to see if Flocean’s ambitious vision becomes reality. If successful, this first commercial facility at Mongstad could pave the way for a new era of ocean-based water infrastructure.

The implications extend beyond just providing drinking water. As highlighted in the International Desalination Association’s reports, global desalination capacity has grown by 40% since 2020, while water reuse capacity has surged by 52%. The addition of energy-efficient underwater desalination could accelerate this growth even further.

While challenges remain in terms of scaling the technology and proving its long-term viability, Flocean’s approach represents a promising step toward sustainable water security. As climate change continues to strain global water resources, innovations like these may be essential for ensuring that future generations have access to one of life’s most fundamental necessities.

Conclusion

Flocean’s underwater desalination plant represents more than just a technological innovation—it’s a potential game-changer in the global effort to address water scarcity. By harnessing the ocean’s natural power to halve energy consumption, this technology could make desalination more accessible, sustainable, and cost-effective. As the world faces increasing water stress, solutions that work with nature rather than against it may prove to be our best hope for a water-secure future.

The 2026 launch in Mongstad will mark a pivotal moment in water technology history. Whether this first facility succeeds or faces unexpected challenges, it represents a bold step toward reimagining how we can sustainably meet our most basic human needs while protecting the environment.