Researchers at the University of Illinois Urbana-Champaign say underground aquifers could offer an unexpected solution to one of artificial intelligence’s fastest-growing environmental challenges: cooling the massive data centers that power the technology.
As protests and debates continue over the rapid expansion of AI data centers around the world, researchers are exploring new ways to manage the enormous amounts of energy and water required to keep these facilities running. To meet such demands, the University of Illinois Urbana-Champaign team has proposed an innovative solution: using underground aquifers as natural “thermal batteries” to cool data centers while reducing their environmental footprint.
Critics have raised concerns ranging from the vast quantities of water consumed by AI infrastructure to the ethical implications of job displacement and the broader societal impacts of artificial intelligence. Against that backdrop, designing AI systems that reduce their climate impact could represent an important step toward more sustainable computing.
Researchers Yu-Feng Lin, Andrew Stumpf, and postdoctoral researcher Upasana Pandey from the Prairie Research Institute’s Illinois State Geological Survey explored the potential of Aquifer Thermal Energy Storage (ATES) as a cooling strategy for data centers. The team suggests underground water systems could provide an efficient alternative to traditional cooling methods. Their findings were published in the peer-reviewed journal Groundwater.
“Data centers use large amounts of electricity, and 10 to 40% of that energy can go just to cooling, depending on the design,” Pandey said in a statement. “They also consume tremendous volumes of water, often through cooling methods where water is evaporated and effectively lost from the local supply.”
To address both challenges, the researchers propose using groundwater stored beneath Earth’s surface as a reusable thermal energy storage system. ATES can provide direct or supplemental cooling by circulating groundwater through underground pipes. Cool groundwater absorbs heat through a heat exchanger before the warmed water is returned to the aquifer for seasonal storage. The system can also store excess summer heat for winter heating and preserve cold winter water for use during the summer months.
“In places like Illinois, where we experience seasonality, and when the subsurface geology is ideal, instead of constantly trying to moderate the outdoor temperatures that swing from 90°F in summer to minus 10°F in winter, we can tap into the Earth’s near-constant temperature,” Stumpf said. “You’re no longer adjusting from 90°F to 70°F; you’re adjusting from about 55°F to 70°F. That’s a huge energy savings.”
Illinois is particularly well-suited for aquifer thermal energy storage because of its pronounced seasonal temperature swings, favorable aquifer characteristics, and suitable subsurface geology. The system can utilize non-potable water sources, including deep saline aquifers, contaminated groundwater, and even abandoned mines.
According to the researchers, the primary barriers to broader adoption are the high upfront installation costs and relatively short investment timelines, rather than technical feasibility.
“Data centers sit at the center of the water-energy nexus: If you try to reduce energy use, you often use more water, and if you reduce water use, you may need more energy,” Lin said. “Our work looks for solutions that address both together.”
“Water is a magic material in this context because it has high heat capacity and can be a good thermal carrier with flow,” he adds.
“That combination is rare, and in groundwater, we can tap those same properties for energy storage.”
Chrissy Newton is a PR professional and the founder of VOCAB Communications. She currently appears on The Discovery Channel and Max and hosts the Rebelliously Curious podcast, which can be found on YouTube and on all audio podcast streaming platforms. Follow her on X: @ChrissyNewton, Instagram: @BeingChrissyNewton, and chrissynewton.com. To contact Chrissy with a story, please email chrissy @ thedebrief.org.