Seawater desalination has traditionally called for a lot of energy.
Today's desalination processes remove salt and minerals from water by forcing it all through a membrane – a method known as reverse osmosis. That driving force, however, requires a significant amount of power, frequently provided by fuel, phovoltaics, or wind.
For island countries like Cape Verde, desalination processes rely on diesel-electric systems.
Olivier Ceberio, Chief Operating Officer of a startup company called Resolute Marine Energy , sees a cleaner option, and a consistent, steady, renewable energy right in the ocean itself. Ceberio wants countries like Cape Verde to test out a new desalination method, powered by waves.
The technology, Wave2OTM, harnesses the energy of ocean currents to turn saltwater into freshwater. The Wave2O Technology was the Sustainable Technologies category winner in this year's Create the Future Design Contest. (See the rest of the 2019 'Create the Future' winners.)
How Wave2O Works
To create the required desalination energy, a kind of flap, attached to the bottom of the sea, moves back and forth with the waves, generating enough energy to send pressurized seawater offshore – and enough power to support a standard reverse-osmosis unit.
The Wave2O team began testing its modular assembly process in North Carolina in 2012. Equipment was transported via container and assembled in hours on the beach.
Ceberio’s team hopes to bring the same kind system to Cape Verde, a country that generates 85% of its water supply diesel-electric desalination systems.
"In remote communities and island nations, the incumbent solution is diesel-driven desalination systems, which are not only expensive but also polluting," Ceberio told Tech Briefs. "So in addition to being economical, our system can displace carbon emission."
In January of 2018, the European Union awarded Resolute Marine a €50k "SME Instrument Phase 1" grant to demonstrate the economic feasibility of a wave powered desalination system.
Ceberio and his team plan to implement the first commercial demonstration of Wave2o in Cape Verde within two to three years.
In the interview below, Ceberio spoke with Tech Briefs about how the energy idea came about, and how his company will continue to make waves.
Tech Briefs: Can you quickly explain the role of ocean waves in your technology? It’s a very interesting idea — to use ocean waves in the way that you do. What inspired this choice?
Olivier Ceberio: It started with the frustration that over one billion people suffer from the effects of water scarcity and the realization that a vast majority of those affected live in coastal areas in developing countries and remote communities.
Seawater desalination is an excellent potential solution, but desalination is expensive because it is energy intensive. The absurdity is that desalination also happened to be just next to one of the cleanest, strongest, and steadiest sources of energy: ocean waves! And that’s what we do: We use ocean waves to drive a desalination system and provide fresh water to these people.
Tech Briefs: Can you take us through an example as a way of demonstrating how the process works?
Olivier Ceberio: The way it works is simple: a Wave Energy Converter.
A flap, attached to the bottom of the sea, moves back and forth with the waves. It extracts energy from the waves and uses it to pressurize seawater that is then sent to the shore where it goes through filters to directly produce fresh water, a process called reverse-osmosis.
So the main feature of our system is that seawater is [simultaneously] the input to the desalination process and the energy medium to drive it. As a result, the system uses only ocean waves to produce fresh water and does not require any other source of energy and operates off-grid.
Though the system does not use electricity in its process, it can, however, co-generate electricity so that the water can be pumped where it’s needed or to provide both water and power to our communities.
Tech Briefs: How is your method better than traditional desalination processes?
Olivier Ceberio: In remote communities and island nations, the incumbent solution is diesel-driven desalination systems, which are not only expensive but also polluting. So, in addition to being economical, our system can displace carbon emission. We calculated that a 4,000 m3/day plant would reduce CO2 emission by an equivalent of taking 900 cars off the road permanently!
Tech Briefs: How much clean water can be produced?
Olivier Ceberio: There is no upper limit from technology constraints. Our system is modular. Each module has a rated capacity of 500 m3/day. A typical plant would have between 10 and 12 of these modules to produce an average of 4,000 m3/day depending on wave energy conditions. That’s enough to cover the need of 40,000 people in our communities, but we could imagine a plant as big as 50,000 m3/day for larger cities.
Tech Briefs: Where has this been used and tested out?
Olivier Ceberio: Our technology has been under development for the last ten years, financed mostly by grants from the U.S. Department of Energy and private investment. We completed several wave tank testing and ocean trials of our technology during this time, and we are now preparing for our first commercial demonstration in Cape Verde, our launch market, within 2-3 years.
Tech Briefs: What’s next?
Olivier Ceberio: Right now, we are validating our integrated system in lab conditions. Our next step is to test it in ocean conditions in PLOCAN , an ocean testing platform located in the Canary Islands. Our next milestone will be to test our technology at commercial scale in Cape Verde with our first customer. Once successful, we will be able to launch our global commercialization.
Tech Briefs: What’s most exciting to you about this technology?
Olivier Ceberio: So many things! We believe we are nearing the end of our development, and we cannot wait to see our system operating in Cape Verde. But what is also really exciting is to see that the context around us seems to be converging! The issue of climate change is becoming ripe. More and more people are mobilizing to find solutions and part from the status quo, and we are ready to ride that wave (pun intended).