clean water
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Solar-Powered Technology Turns Seawater into Fresh Water, Offering Hope for Global Water Crisis

More than 4 billion people around the world need access to clean water. Now, a new technology developed in Canada could help decrease that statistic overnight.

A University of Waterloo research team reports the development of an energy-efficient device that uses solar power to turn seawater into drinkable water. 

Water quality is essential for healthy living, and recent research highlights how contamination affects large portions of the population in several regions worldwide. Sadly, on August 15 of this year, according to a recent geospatial analysis and statistics published by the Swiss Federal Institute of Aquatic Science and Technology, 4.4 billion people in low—and middle-income countries still lack access to safe drinking water at home—double the 2 billion estimated in 2020 by the World Health Organization and UNICEF’s Joint Monitoring Programme, which monitors global progress on clean water.

“The water crisis is not solely a technical problem, so a technical solution alone will not solve it,” said  Vincent Casey, Water Security Lead at WaterAid, a nonprofit organization The Debrief reached out to about the need for such technologies, and how they could help resolve issues with access to drinking water that over 4 billion people worldwide experience.

“In many parts of sub-Saharan, for example, groundwater tends to be largely available within 20m of the surface, so it’s often a lack of investment in the services needed to get water to people that prevents people from accessing water, not always a lack of it. Getting water to people is, therefore, about investing in water service providers, and maintenance providers, adapting water supply solutions to different contexts, and effective management of water resources.”

“It’s about fixing the whole system,” Casey said. 

“However, in some coastal communities where there is not enough safe water to meet demand or sources are being contaminated by seawater, desalination is an important method to ensure people have enough clean water to meet their basic needs, provided the finances, expertise, and supply chains exist to sustain desalination based services,” he added. 

Current desalination systems work by pumping seawater through membranes that separate salt from the surrounding water. While effective, this method is energy-intensive and can lead to salt buildup on the membrane’s surface, blocking water flow and reducing efficiency. As a result, these systems require regular maintenance, making it challenging to operate continuously in remote or underdeveloped areas with a lack of supplies or knowledge in mechanical engineering.  

Such issues inspired researchers Dr. Michael Tam and PhD students Eva Wang and Weinan Zhao to consider natural earth based elements to solve such a complex problem.

“Our inspiration comes from observing how nature sustains itself and the way water evaporates and condenses in the environment,” said Dr. Michael Tam, a professor in Waterloo’s Department of Chemical Engineering, in a press release. 

“The system we’ve engineered induces water to evaporate, transports it to the surface, and condenses it in a closed cycle, effectively preventing the accumulation of salt that reduces the efficiency of the device,” Dr. Tam, with the Department of Chemical Engineering at the University of Waterloo, told The Debrief in an email.

“The device is solar-powered and can convert about 93 per cent of the sun into energy, five times better than current desalination systems,” It produces around 20 liters of fresh water per square meter—enough to meet the World Health Organization’s daily recommendation for basic drinking and hygiene needs per person.

The University of Waterloo research team created the device using a special nickel foam covered with conductive plastic and tiny particles that respond to heat. This material can soak up sunlight and turn it into heat. A thin layer of salt water sits on the plastic, and the heat makes the water rise, like water moving up through tree capillaries. As the water evaporates, the salt gets pushed down to the bottom of the device, similar to how dirt settles in a swimming pool filter. This keeps the system from getting clogged and keeps working smoothly.

“This new device is not only efficient but also portable, making it ideal for use in remote regions where access to fresh water is limited,” Li said. “This technology offers a sustainable solution to the emerging water crisis,” says Dr. Yuning Li, a professor in Waterloo’s Department of Chemical Engineering, in a press release. 

Casey feels similar to what Dr. Yuning suggests: “Any technology needs to be affordable in a local context. Filters play a crucial role in making the water safe, but if you’re not blocking other routes of transmission (e.g., flies on food, handwashing after toilet use), you will still have problems, so any filter has to be part of a combined solution.”

In the future, the University of Waterloo team, located in Waterloo, Ontario, Canada, plans to build a larger-scale model by taking it out to sea and testing its capabilities there.

Going forward, the Waterloo researchers plan to build a prototype of their device that can be deployed at sea to test the technology on a larger scale. If the test is proven successful, the technology can sustainably supply fresh water to coastal communities and fulfill the UN SDG Goals #3, 6, 10, and 12,” said Professor Tam. 

“When a community gets clean water, it changes everything now and long into the future. This means that children will grow up free from diseases caused by dirty water. Girls spend their time in school instead of fetching water for their families, and entire communities break free from poverty,” said Casey.

The original paper was published in Nature.

Chrissy Newton is a PR professional and founder of VOCAB Communications. She currently appears on The Discovery Channel and Max and hosts the Rebelliously Curious podcast, which can be found on The Debrief’s YouTube Channel on all audio podcast streaming platforms. Follow her on X: @ChrissyNewton and at chrissynewton.com.