A team of researchers in South Korea has developed a groundbreaking solar desalination device capable of producing 3.4 liters of fresh water per hour—entirely without electricity. This innovation, created at the Ulsan National Institute of Science and Technology (UNIST), could offer a lifeline to communities facing water scarcity and limited access to power.
Turning Sunlight Into Fresh Water
The device uses a simple yet highly effective mechanism. It consists of a paper-like strip that draws in seawater through capillary action. Once the water reaches the top of the strip, it is exposed to a layer of advanced material known as LSMO (La₀.₇Sr₀.₃MnO₃), which absorbs sunlight and converts it into heat. This heat causes the water to evaporate, leaving salt and impurities behind.
What makes this system especially remarkable is its ability to self-clean. Traditional solar desalination setups often suffer from salt accumulation, which can block sunlight and reduce efficiency. The Korean device solves this by directing salt particles to the edges, where they crystallize and can be easily removed. This ensures consistent performance and even allows for salt harvesting.
Efficiency and Durability
Under natural sunlight, the system achieves an evaporation rate of 3.4 kilograms per square meter per hour. That’s nearly ten times faster than passive evaporation methods. Even when tested with highly concentrated saltwater, the device maintained its performance for over two weeks without clogging or degradation.
This level of efficiency and resilience positions the technology as a strong candidate for deployment in coastal regions, disaster zones, and rural communities where clean water and electricity are scarce.
Benefits for Communities and the Environment
The implications of this innovation are far-reaching:
- No Electricity Required: The device operates entirely off-grid, making it ideal for remote or underserved areas.
- Low Cost and Scalable: Its simple design and affordable materials suggest it could be mass-produced and distributed widely.
- Environmentally Friendly: It avoids chemical treatments and uses renewable solar energy, minimizing ecological impact.
- Dual Purpose: In addition to producing drinking water, it enables salt collection, which could support local economies.
A Step Toward Global Water Security
As climate change intensifies and freshwater resources become increasingly strained, solutions like this offer hope. The Korean team, led by Professor Ji-Hyun Jang and Dr. Saurav Chaule, is now working to scale the technology and explore commercial applications. Their goal is to make clean water accessible to all—using nothing more than sunlight and smart design.
This breakthrough not only advances the science of desalination but also represents a powerful step toward a more sustainable and equitable future.