A Wave-Powered Solution to the Water Crisis

Water scarcity is a major concern as the planet warms. Desalination has emerged as a workable solution, but traditional methods tend to be energy-intensive and costly. So two questions: what’s wrong with conventional desalination, and what’s the solution you’ve developed?

Conventional desalination methods, while effective in producing fresh water, come with significant drawbacks. These conventional systems essentially convert fuel into water. Although this method produces the needed fresh water, it is energy-intensive, contributing to carbon emissions and environmental damage, and is costly. 

Water scarcity is an escalating concern in many regions, often worsened by the effects of climate change, which can lead to drier conditions and reduced water availability. Faced with water scarcity, society frequently turns to traditional desalination methods. Yet, these exacerbate the problem they seek to solve by significantly contributing to climate change through high carbon emissions. This establishes a harmful feedback loop: as climate change continues to intensify, it aggravates the situation of water scarcity, prompting increased dependence on fossil fuel-driven desalination, which, in turn, fuels further climate change. These factors underscore the need for more sustainable and environmentally friendly water production methods, especially in the face of urgent global environmental concerns.

Using a patented wave-powered desalination solution, we are turning seawater into freshwater using only the renewable energy created through ocean waves. Oneka offers modular and drought-proof solutions that have the capacity to meet different water needs: tiny communities, water-intensive industries, large municipalities, and emergency relief applications. 

Our wave-powered desalination systems have been designed to operate in synergy with the marine and terrestrial environments. For each cubic meter of water produced daily by Oneka, approximately 1 ton of carbon dioxide per year is avoided compared to traditional desalination. Our self-sufficient systems require no additional external energy, delivering water off-grid. Oneka's technology minimizes environmental impact by rejecting brine only 30-50% saltier than that of the ocean and is discharged near the surface in a moving water column, so the brine is quickly diluted to the salinity of the ocean. Our offshore modular systems also reduce the land footprint, avoiding the high costs and environmental concerns associated with coastal land use.

Finally, by harnessing the renewable energy contained in the ocean waves, Oneka possesses the potential to fulfill its mission to make the oceans a sustainable and affordable source of freshwater. 

Walk us through how Oneka’s machine works — how does a floating, wave-powered raft turn seawater into fresh, drinkable water?

Each desalination unit, which looks like a floating raft, is anchored to the seafloor with a big tether. The system has the ability to harness the natural, oscillating motion of ocean waves. As the buoy dips down into a wave trough, seawater is drawn into the system through a strainer. This strainer helps in filtering out larger particles and debris from the seawater.

Then, as the buoy rises with the wave, the seawater inside the system is pressurized. This is achieved through a mechanical pump that is activated by the buoy's upward motion. This pump is similar to a bicycle pump; as it moves up and down, it does the pumping. The pressurized seawater is then forced through reverse osmosis membranes. These membranes are designed to allow only water molecules to pass through while blocking salt and other impurities. The result is the extraction of fresh, drinkable water from the seawater, which is then pumped towards the shore. The system utilizes the residual energy from the wave motion for this purpose, making the entire process energy-efficient. The fresh water can either be directly integrated into the local water distribution network or stored in tanks for later use.

The leftover water, which now has a higher concentration of salt (commonly referred to as brine), is discharged back into the ocean. This is done in a way that minimizes environmental impact.

In summary, Oneka's system combines the natural energy of wave motion with advanced filtration technology to provide a sustainable solution for freshwater production. It's a self-sufficient system that minimizes environmental impact and operates without the need for external power sources.

At Aspen Ideas: Climate, we’re always curious how ideas transform into action. Initially your career was focused on mobility and electric vehicles. How did you come up with the idea for wave-powered desalination?

Twelve years ago, while I was traveling in Corsica, a dry place surrounded by an ocean with abundant seawater, a question struck my mind while taking a shower: where does this water come from? I was aware that it was possible to generate electricity from waves and to convert seawater into freshwater using electricity. Why not take the electricity out of the equation? While I knew basically nothing on desalination, I imagined a sort of vacuuming system. The actual result after more reading on the subject lead to a much more viable approach, one that could replace the conventional desalination methods that were extremely costly and environmentally damaging due to the huge amount of energy they required.

This led me to build a team to design a modular and scalable solution that wouldn’t rely on fossil fuels and would use far fewer components compared to traditional methods. I continued to travel around the world, meeting people who were grappling with water scarcity issues. These encounters solidified my belief in the urgent need to harness the ocean — a boundless and readily accessible source of both water and energy — to provide sustainable and affordable desalination solutions to coastal communities and industries worldwide.

What are your plans to scale this technology so that more coastal communities can benefit?

Initially, Oneka is focusing on small-scale projects in coastal communities and industries where the challenges of water access are significant, and where water supply and electricity is currently more expensive. The regions of the Caribbean, Chile, and California have been identified as initial target areas, not only due to their pressing water needs but also because of their wave regimes, which are particularly suited for Oneka's wave-powered technology.

To expand beyond beachhead markets, Oneka is working to reduce costs and take advantage of economies of scale. This approach is crucial for addressing the larger water needs of major municipalities, water-intensive industries, and eventually even the agricultural sector. By lowering the costs, Oneka's technology will become a more viable option for a broader range of coastal communities and industries across the world. 

Additionally, Oneka places a strong emphasis on offering water as a service, while creating local job opportunities. This approach involves training local teams for each project, aiming to make communities self-sufficient in managing their water supply. This strategy not only fosters local economic development but also reduces dependence on fuel imports for many small states. The creation of local jobs and the development of local expertise in managing and maintaining the desalination units is a sustainable way to ensure the long-term success and scalability of the technology.

Let’s talk about entrepreneurship and business in the context of climate change. You really sit at the nexus of these areas, securing support and investors for new technology aimed at climate solutions. What have you learned throughout this process? Do you have any advice for others in the climate tech space?

Timing is crucial for the success of climate tech ventures. We experienced a fortunate convergence of growing interest and investment from both the industry and investors. This serendipitous timing can sometimes be a matter of luck, but it's also about being prepared to seize opportunities as they arise. This trend reflects a growing momentum in the climate tech sector, indicating a receptive market and a potential increase in funding and support.

We live in a highly connected yet small world. In my journey, starting early and attending key industry events significantly accelerated the expansion of my network. Connecting with influential people and industry leaders can provide invaluable insights, open doors to new opportunities, and help overcome challenges. I'd strongly recommend reaching out to key individuals who can assist in navigating the complexities of the climate tech landscape.

In addition, the due diligence process by investors and supporters should be seen not as a hurdle, but as an opportunity to strengthen your business. This process can serve as a powerful accelerator, challenging you to refine your business model, improve your strategies, and view your company from various perspectives. It's an opportunity to bolster and enhance your venture.

While clean tech is often linked to renewable energy, which is key for mitigation of climate change, adaptation is also crucial. Water is so essential for adaptation, considering that it is a finite, depleting resource. I feel privileged that at Oneka, we have the opportunity to both adapt to and mitigate climate change.

The views and opinions of the author are their own and do not necessarily reflect those of the Aspen Institute.