Engineers from MIT have developed a groundbreaking desalination system that runs entirely on solar power without needing extra batteries.
This innovative system can remove salt from water by adapting its energy use to the amount of sunlight available, offering a more efficient, low-cost way to produce clean drinking water.
The research, published in Nature Water, highlights the potential of this technology to provide much-needed drinking water, especially in areas with limited access to electricity or seawater.
Unlike traditional desalination systems that rely on fossil fuels or need constant energy supplies, this solar-powered system adjusts its operations based on sunlight levels.
As the sun rises during the day, the system increases its desalination rate, and when clouds block the sun, the system quickly reduces its energy consumption.
This flexibility allows the system to maximize the use of solar energy without needing a battery or a backup power source.
The system was tested on groundwater wells in New Mexico over six months, where it produced up to 5,000 liters of clean water per day, even with changing weather conditions. On average, the system converted over 94% of the solar energy into desalination power, outperforming other solar-powered desalination systems.
Professor Amos Winter, the lead researcher and director of the K. Lisa Yang Global Engineering and Research (GEAR) Center at MIT, explained that this system provides a sustainable solution for desalinating brackish groundwater.
Brackish water, found in underground reservoirs, is saltier than freshwater but more common than seawater in many inland areas. This makes it an ideal water source for communities far from the coast.
“Conventional desalination systems need steady power, often provided by batteries, to handle variable solar energy,” said Winter. “Our system, by varying its energy use in sync with the sun, eliminates the need for extra power storage while efficiently producing water.”
The system is based on a process called electrodialysis, where an electric field is used to draw salt ions out of water as it passes through ion-exchange membranes.
By using a control system that adjusts the water flow and electric current based on sunlight, the system can desalinate water quickly and efficiently.
In previous tests, the researchers achieved a 77% efficiency rate, but they continued to improve the system to respond faster to changing sunlight conditions.
In the latest version, the system updates its energy use three to five times per second, allowing it to react almost instantly to changes in sunlight. This means it can maintain high efficiency without needing batteries to store extra energy.
The researchers envision this technology as a game-changer for communities that rely on brackish groundwater, particularly in remote or low-income areas.
Many inland regions depend heavily on groundwater for drinking water, but rising salinity levels due to climate change are making these resources less usable.
This new solar-powered system could provide a reliable and affordable way to desalinate brackish water in these regions.
The MIT team plans to scale up the system to serve larger communities and municipalities, providing clean water for thousands of people. They are also working to improve the system’s reliability and reduce costs even further.
In the coming months, the researchers will launch a company to bring this technology to markets around the world.
“While this is a big step forward, we’re committed to developing even more affordable and sustainable desalination methods,” said co-author Jonathan Bessette. “Our goal is to create a product line that can deliver desalinated water using renewable energy to meet the needs of many different communities.”
Source: MIT.
