At a time when AI data centers are using enormous amounts of water, adding to a man-made crisis that the United Nations calls “the era of global water bankruptcy,” Chinese scientists have created a solar-powered device to efficiently turn seawater into fresh water. In a study published in the journal Advanced Materials, the researchers explain how their blend of nanomaterials and tightly linked polymer chains could make desalinated water cheaper than bottled water after two years of use.
The researchers built a desalination device using their material and found that the machine, which measures about eight square feet, evaporates water at a rate 8.5 times higher than existing solar desalination methods. This allows it to produce just over five gallons of clean water each day under natural sunlight.
This is a major breakthrough for a technology that is becoming increasingly vital, especially in regions like the Middle East, Africa and California, where fresh water is scarce. Existing desalination methods – thermal and reverse osmosis – require a lot of energy, making them cost-prohibitive and environmentally unfriendly. Until now, solar-powered desalination has been less efficient and difficult to implement. This is why a material that can be used to efficiently produce clean, safe water to consume without burning fossil fuels is so promising.
Making desalination affordable is huge
Although it covers most of the planet’s surface, only an extremely small percentage of Earth’s water is drinkable. As demand increases, making seawater drinkable becomes a crucial tool to increase supply and prevent prices from skyrocketing – provided it can be done inexpensively, without requiring the burning of the same fossil fuels that have led to the water and climate crises.
One area where efficient solar desalination could make a difference is in data centers. Since salt water would leave residue, leading to clogs and damage to equipment, the installations would eat into the already depleted fresh water supply. The ability to desalinate water efficiently and in large quantities wouldn’t solve all of AI’s data center problems, but it would at least prevent them from depleting local water supplies.
Desalinated water is also useful for irrigating crops. The Chinese researchers behind the desalination machine used the produced water on a six-square-meter field and found that it “successfully supported the full growth cycles of various crops,” including spinach, corn and Chinese cabbage. This could make a difference in regions where extreme droughts cause crop failures and famine.
This is far from the only effort. A University of Rochester project has found a way to use laser-treated solar panels to distill seawater without leaving behind brine — concentrated salt water, minerals and (in most cases) chemicals used to pre-treat the water. Brine is often discharged into the sea or elsewhere in the environment, which can pose a danger to wildlife, groundwater and soil quality. The University of Rochester’s discovery allows leftover salt to be recovered in solid form, allowing them to be reused and avoided waste.
