Artificial intelligence has real thermal problems.
Cooling next-generation computer chips for AI will require millions of gallons of water or large amounts of electricity. Both aroused fierce public opposition.
The industry’s thermal tradeoffs threaten to deepen its unpopularity in communities where concerns about the economic and environmental burden of data centers are growing. When businesses choose to conserve water when cooling their facilities, electricity demand spikes. Reducing electricity increases water usage. One option would increase carbon emissions and strain the power grid. The other depletes natural resources.
“There are no easy answers. There are a lot of tradeoffs to this,” said John Ikeda, chief mission officer at the Water Environment Federation, a technology and education nonprofit organization for water professionals that has worked with Amazon on data center issues.
POLITICO spoke to four major technology companies about how they choose between using water or energy to cool their facilities, knowing that using either would tax resources and invite public backlash.
Microsoft and Quality Technology Services have committed to zero water usage at the cost of increased electricity usage and potential carbon emissions. Google and Amazon say they use water to relieve pressure on power grids in humid climates, but not in drought-prone regions.
While companies prioritize different risks, most are trying to find innovative solutions to thermal problems. Amazon has developed a system that will reduce the company’s North American water use by 946 million liters in 2024. This is equivalent to drinking water for 1.3 million people per year. And the company improved its water efficiency by 17% that same year. Microsoft is experimenting with a new technology that could make AI computer chips work at higher temperatures, reducing their power demands for cooling.
Steve Solomon, vice president of data center infrastructure engineering at Microsoft, said:
Still, the enormous amounts of water and electricity required for the facility have sparked public opposition. A recent Gallup poll found that 7 in 10 Americans oppose data centers, citing water use as their top concern.
In the first quarter of 2026, 75 projects worth at least $130 billion were halted due to local opposition, according to tracking firm Data Center Watch. And county-level moratoriums are becoming increasingly common.
“You can cool a data center without using a single drop of water, but it’s very energy-intensive,” said Ikeda, who has worked with technology companies to help power companies understand data center water needs.
“Alternatively, you could use 100% water for cooling to reduce energy use, but depending on the season and temperature, you would be competing with local water demand.”
In other words, water usage, electricity demand, and carbon emissions are closely linked. Optimizing one often makes the other worse. And because the industry rarely shares process details, few people outside the company have enough information to assess the impact.
One of the problems for local governments wondering whether to green light data centers is the lack of transparency. Most technology companies don’t fully explain the details behind the trade-offs with hydropower. There are no federal disclosure requirements, and businesses that share information through sustainability reports use discrepancy metrics and varying levels of granularity.
“No other major energy-consuming sector in the United States, no other sector that is growing as rapidly from an economic and infrastructure standpoint, suffers from public data blind spots as much as America’s data centers,” Eric Massanet, a data center expert at the University of California, Santa Barbara, testified before Congress in February.
Water can reduce peak loads
Cooling a data center is a basic physics problem. The computer chips that power our digital economy, like any laptop, can easily overheat and shut down.
An unprecedented heatwave in the UK in 2022, with temperatures exceeding 100 degrees Fahrenheit, forced Google and Oracle to shut down their cloud computing facilities.
“In the past, you could just open the window and let the cool air come in, just like in your house,” Ben Townsend, Google’s head of infrastructure and sustainability, told POLITICO.
“And in the summer, when opening the windows isn’t enough, I close the windows and turn on the air conditioner.”
But as computer chips became more powerful and the summer sun became hotter, large buildings became less and less efficient at air conditioning, requiring hundreds of megawatts of power, comparable to small power plants. To save energy, most data centers have started cooling their systems with water. It can absorb and transport heat more efficiently than cooling the air inside a building. Imagine jumping into a cold ocean compared to turning on your air conditioner.
“Water has a unique and incredible power to reduce energy consumption and associated grid constraints and emissions,” Townsend said.
According to Google’s own calculations, using 264 million gallons of water for cooling in Central Europe would reduce data center electricity demand by 41,000 megawatt hours, enough to power 10,000 homes.
Today, most hyperscale data centers use a water-intensive process called “evaporative cooling” to reduce energy demands, at least for part of the year. There are several ways to evaporate water for cooling, but a common strategy is to use water to absorb heat from the data center and release steam into the atmosphere. This is similar to cooling towers used in power plants.
This technology may also be introduced in water-scarce areas, potentially putting a strain on natural resources. A recent report found that two-thirds of U.S. data centers built after 2022 will be located in regions experiencing high levels of water stress.
As a result, new facilities are beginning to use more advanced methods, such as adiabatic cooling, which first sprays water to cool the outside air that is pumped through the data center. Hybrid systems evaporate water during the hottest months of the year, but use outside air most days.
Amazon Web Services is planning a facility in Louisiana that the company says will use outside air for cooling “87 percent of the year.” By using evaporative cooling for the remainder of this year, Amazon will reduce the facility’s electricity demand by 25 to 35 percent “at the same time the grid is experiencing summer peak loads,” said Beau Schlitz, who leads the company’s water infrastructure strategic efforts.
Facilities in warmer climates, such as Ohio, may only need water cooling 3% of the year, AWS says.
No matter the climate, the reason for using water goes back to saving electricity.
“Everyone is running their air conditioners and trying to not constrain the grid at a time when it is most constrained,” Schlitz said. “On hot days when everyone wants to cool their homes, we use water to reduce peak power usage.”
Google and Amazon say these advances have dramatically reduced water usage. Google’s data centers around the world consumed 8.1 billion gallons of water in 2024, according to sustainability documents. The company says that amount is equivalent to the irrigation needs of just 54 golf courses.
Amazon’s data centers will use even less water in 2025, to 2.5 billion gallons, about 5% of Seattle’s annual water use. This roughly equates to a 2% reduction in water usage.
Google and Amazon are prioritizing water-saving technologies in certain drought-prone areas, such as Phoenix and Cape Town, South Africa.
Google’s Townsend said, “In areas of high stress and areas where supplies are scarce, a hard no is without evaporative cooling towers.”
This ensures that you will never run out of resources needed to operate your data center.
“Using recycled water also limits the risks to our business,” Schlitz said, noting that Amazon is helping build a water recycling plant in Loudoun County, Virginia. “We don’t want to use potable water for cooling in places where we might not have an adequate water supply in the future.”
Even when data centers try to reduce water usage, large facilities often face resistance due to the amount of resources they consume. Arriving in a new location will inevitably increase your water usage and compete with other large consumers.
“We already have real estate developments, cities, dairies, agriculture and ranches competing for water resources, and now we’re adding data centers on top of that,” said Andrew Coppin, whose business, called Ranchbot, helps ranchers and farmers track their water usage.
“I don’t know about you, but I’d rather have steak and salad than ChatGPT.”
Also, the less water a data center uses, the more electricity it needs.
Take, for example, two Google facilities in Nevada. The Las Vegas facility will use 359.9 million gallons of water for cooling and reduce electricity usage in 2024, according to sustainability documents. The other one in Reno was not equipped with evaporative cooling and required more power.
“Moving from evaporative cooling to air-based cooling dramatically increases energy consumption and increases emissions,” Google’s Townsend said. “So when we first started operating, we evaluated what a zero water goal would look like. The projected emissions were something we had to take seriously.”
Zero water promise
Even as technology companies roll out newer, faster computer chips to power AI, the basic choice between water and electricity will still be affected. Because these chips can process so much information in a given amount of time, they can overheat even faster, leading companies like Microsoft and Amazon to develop additional layers to cool them.
This is known as closed loop cooling.
This involves running a liquid through a cold plate that contacts the computer chip. This system has no liquid outlet and does not increase data center water usage when filled with liquid.
Closed-loop cooling has become a buzzword for developers looking to allay local concerns about their facilities’ water usage. The community may request to use this method. A spokesperson for Quality Technology Services, a leading data center developer, said all facilities built by QTS since 2019 use closed-loop cooling systems. The company expects the number of new data centers with “waterless cooling systems” to more than double over the next three years.
“We expect our (water reduction metrics) to continue to improve rapidly as these buildings come online,” spokeswoman Stephanie Blakely said in an email.
However, even data centers with these systems must remove heat from the fluid loop and the data center building itself. For Amazon and Google, this means using some form of evaporative cooling.
Microsoft took a different approach.
Using air to dissipate heat removes heat from a closed-loop system, increasing energy usage.
“But the trade-off is zero water,” says Microsoft’s Solomon.
Amazon’s Schlitz said the promise of zero water could be misleading. “There’s a lot of confusion out there” about closed-loop systems, he said.
Although closed loops reduce water, operators still need to exclude heat from the loop and the building. And water is often the most effective method, especially when temperatures are above 85 degrees, he said.
Townsend said the companies’ different approaches to closed-loop systems can be confusing to communities that may associate them with zero water use, and in some cases may be intentionally misleading.
“You don’t really know how you’re cooling your data center unless you ask specific questions like, ‘How is the cooling plant removing heat? Is it an air chiller, a dry cooler, or an evaporative cooling tower?'” he said. “Then you can really understand if there’s a lot of water usage.”
Massanet, of the University of California, Santa Barbara, added that companies’ reluctance to share detailed information is creating a “PR nightmare” and fueling public mistrust.
“The big challenge in this area right now is the lack of transparent and consistent information being reported,” says Lindsey Rogers, municipal conservation policy manager at climate change advocacy group Western Resource Advocates.
“I think the secrecy has led to a lot of the public backlash that we’ve seen with these projects,” she said.
