At a glance 2 min

A sustainable ocean desalination solution

Although desalination is gradually becoming the leading solution to the imbalance between the demand for water and the quantity available in the world, the existing processes are expensive, energy-consuming and emit large quantities of greenhouse gases.
A sustainable ocean desalination solution
A sustainable ocean desalination solution

It was during a trip to Corsica that Dragan Tutic, co-founder of the Canadian company Oneka Technologies, came up with the idea of creating a low-cost, eco-friendly technology that uses the movement of waves to desalinate water from the sea to produce water for human consumption.
For Oneka - which means water in Mohawk - the premise was simple: use the ocean, which has both the resources and the energy. There's a lot of energy in the ocean, it just needs to be captured.

The ocean, a sustainable, accessible and affordable source of fresh water

To do this, the company developed a small desalination device made from 170,000 recycled plastic bottles: self-contained, floating modular systems that use the mechanical energy of waves to desalinate and pump water to shore. Anchored to the ocean floor, the Oneka buoys float on the surface between 500 m and 1.5 km from the coast, anywhere the average wave height is greater than 1 m (~3 ft). The oscillating movement of the waves is harnessed to drive a linear water pump. The sea water is pressurised as the buoys rise and is propelled through the treatment system. The water is filtered, desalinated by reverse osmosis and energy is recovered before it is released into the sea. Again using wave energy, the fresh drinking water is transported to the shore through an underwater high density polyethylene pipe anchored to the ground. The water can then be stored and/or distributed. The brine discharged from these buoys has a negligible impact on marine life as its salt concentration is only slightly higher (+30%) than that of the ocean, and is dispersed by each unit individually.

A zero fuel, zero electricity, zero CO2 solution

The Iceberg class units are designed to produce between 30 and 50 cubic metres (8,000 to 13,000 gallons) of water per day, enough to meet the daily needs of 100 to 1,500 people, depending on lifestyle and consumption. On-board sensors, powered by small solar panels, continuously test the water produced and ensure that it meets current standards. Oneka offers post-treatment to adjust the taste of the water or to adapt it to the needs of agricultural users.

Making drinking water accessible to all

This solution, unlike conventional desalination systems powered by gas and electricity, does not emit significant amounts of greenhouse gases. Each Iceberg class buoy saves approximately 100,000 kg of CO2 per year. The modular and scalable system allows the number of buoys to be adjusted according to the customer's needs. Simple, energy-efficient and environmentally-friendly, Oneka's system comes in 3 different sizes. The smallest of these has been designed to respond quickly to disaster situations and provide the equivalent of about 2,000 bottles of water per day to populations in distress.

A few months ago, Oneka Technologies received a US$729,000 grant for its Snowflake desalination technology by winning the U.S. Department of Energy (DOE) Waves to Water Grand Prize. The competition aims to accelerate the development of wave-powered systems to meet the drinking water needs of remote coastal communities and populations affected by natural disasters or extreme climate change.

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