From Seawater to Drinkable Water Using Wave Power
Oneka Technologies launches a renewable energy-powered way to produce drinkable water
A Canadian start-up called Oneka Technologies has developed a floating desalination system that can turn seawater into drinkable water using renewable wave power.
Oneka’s small desalination machines require less energy to remove salt than large, shore-based desalination plants and run on renewable wave power. Their sustainable destination machines can provide freshwater to coastal communities and industries with less environmental impact than large-scale, energy intensive land-based systems.
Oneka’s chief innovation officer Susan Hunt said, “Desalination facilities are conventionally powered by fossil fuels, but the world has certainly reached a pivot point. We want to move away from fossil fuel-powered desalination.”
There are currently 21,000 desalination water plants worldwide and that number is expected to grow as global population increases and climate change strains freshwater supplies. One 2020 study predicted the desalination sector would increase 9% annually by 2030.
According to the International Desalination Association, more than 300 million people rely on desalinated water worldwide. At least half of the world’s population “live under highly water-stressed conditions for at least one month of the year,” according to a report published earlier this year.
Oneka’s all-in-one desalination system offers a greener and more distributed solution for producing drinking water from seawater. Seawater is pumped through filters on offshore buoys using reverse osmosis membranes to obtain high-quality drinking water.
The two traditional methods used to desalinate seawater are thermal and membrane. Currently, these methods don’t use renewable energy, so they are a contributor to increasing greenhouse gas emissions. The more energy-intensive thermal-based system heats seawater until it evaporates, leaving the salt behind. The membrane-based technique, reverse osmosis, pushes saltwater through a semipermeable membrane that filters out salt.
An additional environmental drawback to traditional destination plants is their creation of “dead zones” – areas where salt levels are too high to support marine life. These dead zones form when significant waste streams of highly concentrated salt water or brine have not been adequately diluted before being discharged into the sea.
Oneka’s floating desalination machines absorb energy from passing waves and convert it into mechanical pumping forces that draw in seawater and push it through the desalination system. The fresh drinking water is then pumped to land through pipelines, using only the power generated by the waves.
The company has also found a way to release a lower concentration of brine compared to traditional desalination methods. Susan Hunt said that their system’s buoys take in brine and mix it back in with three quarters of seawater, which is then released back into the sea.
“[Released water] is only about 25% saltier than the original seawater,” Hunt said.
Oneka is working towards turning the ocean into a sustainable and affordable source of freshwater. The company’s co-founder and CEO Dragan Tutic told media that making desalinated water affordable is a key priority for the company.
“The cost of energy can represent up to 50% of the cost of water,” he said.
By utilizing the renewable energy contained in the ocean waves, Oneka has room to grow into the most affordable solution on the market once the company scales its systems and begins mass production.
“Our goal is to approach the global market with our scaled desalination solutions at a lower cost,” Tutic said.
The company has established a subsidiary in Chile after setting up a successful demonstration of the technology there in the ideal wave conditions of Chile’s long coastline and the company is working with communities and the Chilean government to trial a freshwater system there as its first demonstration project.
Article by Ethan Berg, an Occidental College graduate, is a dedicated climate journalist and Digital Media Research Associate at Climate and Capital Media
Article reprinted with Permission as part of GreenMoney’s ongoing collaboration with Climate and Capital Media.