The world's freshwater scarcity has long been a pressing concern, with only 3% of the planet's water being fresh and readily available. As droughts intensify in arid regions, innovators are turning to the ocean's vast resources, harnessing its natural pressure to desalinate seawater through a promising technology called Deep Sea Reverse Osmosis (DSRO).

Conventional desalination methods, such as reverse osmosis, have been around for over a century, but they're energy-intensive and require strong pumps to force water molecules through a membrane. This process consumes about 1.5 kilowatt-hours of electricity per 100 gallons of water produced, with 70% of the energy expenditure going towards running the pumps. As of 2022, approximately 26 billion gallons of water are produced daily through desalination.

DSRO, on the other hand, drops the reverse osmosis equipment deep into the ocean, leveraging the natural pressure at depths of 1,300 to 2,000 feet to push water through the membrane. This approach significantly reduces the energy required, as only small pumps are needed to lift the fresh water back to the surface. The result is a substantial decrease in energy consumption, with estimates suggesting 30-50% less energy is needed compared to traditional onshore desalination methods.

The concept of DSRO isn't new, but it's only recently gained traction due to advancements in deepwater power, communication, and robotics, largely driven by the oil and gas industry. "The timing of this is perfect because the cost curve and the experience curve have really been taken out," said Alexander Fuglesang, co-founder and CEO of Flocean, a startup at the forefront of DSRO development.

Historically, DSRO faced significant challenges, including the harsh ocean environment and the difficulty of powering equipment at such great depths. However, the oil and gas industry's progress in "electrifying the sea bed" has made it possible to use electric pumps, which are more efficient and reliable than their hydraulic counterparts. Remotely operated submersibles have also become more accessible and cost-effective, simplifying the setup and maintenance of deep-sea equipment.

In a DSRO system, desalination pods are deployed on the seafloor, where they use small pumps to push water slowly past the membrane. This slow process allows most marine life to swim away, and OceanWell, another DSRO startup, is developing a mechanism to periodically reverse the flow of the pumps to flush microorganisms out of the filters and membranes, protecting marine life and maintaining filter efficiency.

While DSRO still releases brine that's saltier than the surrounding ocean water, the impact is less severe compared to traditional desalination methods. The brine is more dilute, and the distributed pods release it into the water column, where it disperses within 10-30 meters. This approach reduces the environmental footprint of desalination, making it a more sustainable solution for global water needs.

Despite the initial high capital expenditure required to deploy DSRO systems, the long-term cost savings and environmental benefits make it an attractive solution. Flocean, OceanWell, and Waterise, another DSRO startup, are all projecting significant energy savings and are working towards large-scale deployments. Investors have taken notice, with OceanWell raising $11 million in a Series A round and Flocean securing $9 million in its own Series A funding.

As the global water crisis continues to escalate, the potential impact of DSRO technology cannot be overstated. "We think we can touch a billion people, roughly, and save them from sliding into water poverty," said Robert Bergstrom, founder and CEO of OceanWell. With the Mediterranean and Red Sea basins being targeted for initial deployments, the future of DSRO looks promising, offering a beacon of hope for a water-scarce world.