Desalination Startups Focus on Deep Ocean Water

The Growing Need for Desalination

A significant challenge facing the world today is the scarcity of fresh water. Only approximately 3% of the Earth’s water is fresh, with a limited portion being easily accessible for use.

Desalination: A Century-Old Solution

As droughts intensify in arid regions globally, attention is turning towards utilizing the remaining 97% of water found in the oceans. Desalination, the process of removing salt from seawater, has been employed for over a century by islands, cities, and water authorities.

Reverse Osmosis: The Dominant Technology

The most prevalent desalination technology is reverse osmosis. This method requires roughly 1.5 kilowatt-hours of electricity to produce every 100 gallons of water. As of 2022, approximately 26 billion gallons of water were generated daily through desalination processes.

The Energy Challenge of Reverse Osmosis

However, reverse osmosis is an energy-intensive process. It necessitates powerful pumps to force water through specialized membranes, resulting in a highly concentrated brine byproduct. These pumps often operate at pressures reaching 800 psi, which is about 20 times the pressure found in a typical car tire.

Deep Sea Reverse Osmosis: A Promising Alternative

Experts are actively exploring alternative methods to power desalination, with deep sea reverse osmosis (DSRO) emerging as a promising solution. This innovative approach involves positioning reverse osmosis equipment at depths of 1,300 to 2,000 feet, leveraging naturally occurring pressure to aid water filtration.

How DSRO Works

DSRO minimizes the need for substantial pumps, requiring only smaller units to lift the desalinated water back to the surface. This significantly reduces electricity consumption compared to traditional onshore desalination.

A Long-Held Idea Now Becoming Reality

The concept of DSRO has existed almost since the inception of reverse osmosis, but practical implementation was hindered by the challenges of operating complex technology in the harsh ocean environment. Recent advancements are now making this a viable option.

Advances from the Oil and Gas Industry

The progress can be attributed to innovations within the oil and gas sector, which has extensive experience in deepwater power, communication, and robotics. Alexander Fuglesang, CEO of Flocean, noted that the timing is ideal due to the decreasing costs and increasing experience in these areas.

Electrification of the Seabed

Previously, powering deep-sea equipment was a major obstacle. Robert Bergstrom, CEO of OceanWell, explained that oil and gas companies have effectively “electrified the seabed” in the last decade or two. This shift from inefficient hydraulic systems to electric pumps has dramatically reduced costs and improved operational reliability.

Improved Submersible Technology

Furthermore, the oil and gas industry has driven down the cost and enhanced the effectiveness of remotely operated submersibles. These submersibles are crucial for the setup and maintenance of deep-sea desalination equipment, allowing for repairs without complete retrieval.

Minimizing Environmental Impact

The desalination pods utilize small pumps to gently move water past the membrane, allowing most marine life to avoid the process. OceanWell is also developing a system to periodically reverse the flow, flushing out microorganisms and preventing filter blockage, thereby protecting marine life.

Brine Management in DSRO

Like conventional desalination, DSRO produces brine. However, the brine from DSRO is less concentrated—approximately 10% to 20% saltier than seawater—and is dispersed into the water column from multiple pods, minimizing its environmental impact.

Infrastructure Costs and Scalability

Establishing DSRO requires investment in infrastructure, including power, water, and communication lines, as well as the installation of the desalination pods. Bergstrom emphasized that the initial capital expense is substantial, but costs decrease significantly with larger plants, such as those producing 10 to 100 million gallons per day.

Pod Deployment and Energy Savings

Flocean and OceanWell both plan to deploy between one and ten pods per site. These companies project that DSRO will reduce energy consumption by 30% to 50% compared to onshore reverse osmosis. The resulting cold water can also be used to enhance the efficiency of air conditioning systems.

Investor Interest and Funding

Investors are recognizing the potential of DSRO. OceanWell secured $11 million in Series A funding in November, and Flocean recently announced a $9 million Series A round led by Burnt Island Ventures, Freebird Partners, and Nysnø Climate Investments.

Pilot Projects and Future Focus

Flocean has agreements for demonstration systems in the Maldives and Jordan, with a strategic focus on the Mediterranean and Red Sea regions. Waterise is targeting the mining industry in Jordan, while OceanWell is initially focusing on California.

A Solution to Global Water Scarcity

With water crises escalating worldwide, these companies are optimistic that their technology can provide a vital solution. Bergstrom believes DSRO has the potential to benefit approximately one billion people facing water poverty.