kongsky / Shutterstock.com

A North Carolina startup thinks its desalination device can solve water crises in coastal communities, on islands, and after disasters.   

“Water, water everywhere / Nor any drop to drink”: Samuel Taylor Coleridge’s adage might prove literally true within our lifetimes. Currently, 150 million people live in cities with a perennial shortage of fresh water, and by 2050, this number will increase to nearly 1 billion. On top of that, climate change is expected to cause water shortages for an additional 100 million city-dwellers.

The predictions are dire, but two recent college graduates have invented a solution that could increase fresh-water availability, simply by harnessing the power—and the water—of the ocean.

Chris Matthews, 24, and Justin Sonnett, 25, are co-founders of

SAROS Desalination, a startup that grew out of their senior design project at the University of North Carolina at Charlotte in 2014. Their Swell Actuated Reverse Osmosis System (SAROS) is a a system of high-pressure pumps, built atop a buoy, that powers itself solely with energy drawn from the vertical motion of waves.

The wave-powered system draws in sea water, pumps it at high pressure through a reverse-osmosis membrane, and emits clean, drinkable water, which it stores in a tank until it’s ready to be run back to shore. The team’s first prototype had a pendulum, but the latest, smaller model sits on a buoy and rides the swells of the ocean.

“What’s unique about this is that we don’t need any kind of electricity or fossil fuels that are normally associated with desalination, so it’s very environmentally friendly,” says Sonnett, SAROS’ director of research and development. “It’s also going to be a lot less expensive than traditional desalination plants, which take a whole lot of energy to build and run.”

While traditional desalination plants are doing a good thing, they are expensive to build, rely on a city’s established infrastructure, use a lot of energy, and can contaminate oceans with a heavily concentrated salt runoff. Matthews and Sonnett’s solution is small and portable—their buoy measures four feet in diameter and can fit in the bed of a pickup truck. It’s also relatively inexpensive.

They expect a SAROS unit to retail for around $23,000, with a lifespan of 10 years and the ability to produce 2,000 gallons of clean water per day.

Moreover, the unit’s small size and the fact that it’s self-contained make it ideal for use in developing cities and countries, on islands, in coastal communities, at eco-friendly resorts and military outposts, and for disaster relief—all of which SAROS is targeting as primary uses when the product officially launches within the next two years.

How the SAROS unit works (SAROS Desalination)

“We are still conducting initial conversations with contacts in Hawaii and a few other small-island developing states,” says Laura Smailes, SAROS’ director of operations. Once SAROS has a proven track record, “this will then allow us to partner with NGOs and enter developing coastal areas that are in desperate need of a water solution. These areas, such as the Philippines and Madagascar, could benefit from SAROS, a solution that provides a consistent source of water and price stability and is able to run off-grid.”

Wave energy is, well, the wave of the future. Sonnett says it’s where solar energy was 15 years ago, and several companies large and small are currently developing ways to harness the ocean’s power for various uses.

But while many companies are using wave energy to create electricity (which is then often used to power a nearby desalination plant, for instance), SAROS says it’s the only such company producing clean water directly—which makes the water cheaper and the system more efficient.

John H. Lienhard V, the director of the Center for Clean Water and Clean Energy at MIT, says that while such technology provides certain advantages—namely no carbon emissions and the potential to serve areas that lack grid electricity—there are limitations that mean a system like SAROS isn’t a universal solution.

“Some parts of the world’s oceans are better suited than others,” Lienhard says, noting that the system can only work where waves have the proper intensity to drive it. “A second consideration is the cost of this source of water relative to locally available alternatives, such as solar-energy-driven reverse osmosis or water hauled by truck.”

The SAROS team members admit they’ve thought about other hindrances, too, like barnacles, storms, and even theft. Still, Matthews and Sonnett are confident that their design will work in many areas, though the right wave conditions—windchop, two-to-three-foot waves, and rough water—are key.

After being one of 30 projects chosen from among 3,600 to compete at the Hello Tomorrow Conference in Paris this summer, SAROS is beginning to gain some recognition. The next steps for the team are securing funding, building a second prototype, and establishing partnerships for pilot programs. From there, they hope to bring the technology to market and partner with NGOs to bring clean water to cities that need it.

“It’s never going to be something that’s going to make tons of money, but we just want to see it make tons of water,” Sonnett says.

Top image: kongsky / Shutterstock.com

About the Author

Most Popular

  1. A man wearing a suit and tie holds an American flag at a naturalization ceremony.
    Life

    The New Geography of American Immigration

    The foreign-born population has declined in U.S. states that voted Democratic in 2016, and increased in states and metros that voted for Trump.

  2. Uber Eats worker
    Life

    The Millennial Urban Lifestyle Is About to Get More Expensive

    As WeWork crashes and Uber bleeds cash, the consumer-tech gold rush may be coming to an end.

  3. Transportation

    A Micromobility Experiment in Pittsburgh Aims to Get People Out of Their Cars

    The Pittsburgh Micromobility Collective will create all-in-one mobility hubs near transit stops, to compete with Uber and Lyft and help commuters go car-free.

  4. Sanders walking in front of a large apartment building with men in suits
    Perspective

    This Is How to Make Democratic Candidates' Housing Plans a Reality

    After years of investment in creating affordable housing, the U.S. still doesn’t have adequate supply. Presidential candidates’ plans must address reasons why.

  5. a photo of Uber CEO Travis Kalanick in 2016.
    Transportation

    What Uber Did

    In his new book on the “Battle for Uber,” Mike Isaac chronicles the ruthless rise of the ride-hailing company and its founding CEO, Travis Kalanick.

×