Earlier this year, e-commerce corporation Amazon gained approval to open two new data centers in Santiago, Chile. The $400 million venture is the company’s first effort to locate its data facilities, which guzzle massive amounts of electricity and water to power cloud computing services and online programs, in Latin America — and in one of the most water-stressed countries has in the world, where inhabitants have protested against the expansion of the industry.
This week, the tech giant made a separate but related announcement. It plans to invest in water conservation along the Maipo River, which is the primary source of water for the Santiago region. Amazon is partnering with a water technology company to help farmers along the river install drip irrigation systems on 165 acres of farmland. The plan is poised to save enough water to supply around 300 homes a year, and is part of Amazon’s campaign to become “water positive” by 2030, meaning the company will save or replenish more water than it uses .
The reasoning behind this water initiative is clear: data centers need large amounts of water to cool their servers, and Amazon plans to spend $100 billion to build more of them over the next decade as part of a big bet on its Amazon Web Services cloud computing platform. Other tech companies such as Microsoft and Meta, which are also investing in data centers to support the artificial intelligence boom, have similar water promises amid a growing controversy over the sector’s thirst for water and power.
Amazon claims its data centers are already among the most water-efficient in the industry, and it plans to implement more conservation projects to quench its thirst. However, just like corporate pledges to achieve “net-zero” emissions, these water pledges are more complex than they appear at first glance. While the company has indeed taken steps to reduce water use at its facilities, its calculations do not take into account the massive water needs of the power plants that keep the lights on at those very facilities. Without a greater commitment to mitigating Amazon’s underlying strain on electricity grids, conservation efforts by the company and its fellow tech giants will only tackle part of the problem, according to experts who spoke to Grist.
The powerful servers in large data centers heat up as they process unprecedented amounts of information, and to keep them from overheating, they require both water and electricity. Rather than trying to keep these rooms cool with traditional air conditioning units, many companies use water as a coolant, running it past the servers to cool them down. The centers also require large amounts of electricity to run all their servers: they already account for about 3 percent of US power demand, a number that more than double by 2030. Plus the coal, gas and nuclear power plants that produce that electricity themselves consume even greater amounts of water to stay cool.
Will Hewes, who leads water sustainability for Amazon Web Services, told Grist that the company uses water in its data centers to save energy-intensive air conditioning units and thereby reduce its reliance on fossil fuels.
“Using water for cooling in most places really reduces the amount of energy we use, and so it helps us achieve other sustainability goals,” he said. “We could always decide not to use water for cooling, but we’d really like to because of those energy and efficiency benefits.”
To save on energy costs, the company’s data centers must evaporate millions of liters of water per year. It’s hard to say for sure how much water the data center industry consumes, but the ballpark estimates are substantial. One 2021 study found it US data centers consumed about 415,000 acre-feet of water in 2018, even before the artificial intelligence boom. That’s enough to supply about a million average homes annually, or about as much as California’s Imperial Valley takes from the Colorado River each year to grow winter vegetables. Another study found that data centers operated by Microsoft, Google and Meta extracted twice as much water from rivers and aquifers as the entire country of Denmark.
It’s almost certain that this number has risen even higher in recent years as companies have built more centers to keep up with the artificial intelligence boom, as AI programs like ChatGPT require massive amounts of server real estate. Tech companies have built hundreds of new data centers in the last few years alone, and they’re planning hundreds more. One recent estimate found that ChatGPT is a average size bottle of water for every 10 to 50 chat responses it provides. The on-site water consumption at any one of these companies’ data centers can now be compared with that of a major beverage company such as PepsiCo.
Amazon does not provide statistics on its absolute water consumption; Hewes told Grist that the company is “focused on efficiency.” However, the tech giant’s water consumption is probably lower than some of its competitors – partly because the company has built most of its data centers with so-called evaporative cooling systems, which require much less water than other cooling technologies and only turn on when temperatures get too high. The company pegs its water usage at about 10 percent of the industry average, and in temperate locations like Sweden, it uses no water to cool data centers except during peak summer temperatures.
Companies can reduce the environmental impact of their AI business by building them in temperate regions that have plenty of water, but they must balance those efficiency concerns with concerns about land and electricity costs, as well as the need to be close to major customers. Recent studies have found this data center water consumption in the US is “skewed toward water stressed subbasins” in places like the Southwest, but Amazon has clustered much of its business further east, especially in Virginia, which boasts cheap power and financial incentives for technology firms.
“Many of the locations are driven by customer needs, but also by [prices for] property and power,” said Hewes. “Some large portions of our data center footprint are in places that are not very hot, that are not in very water stressed areas. Virginia, Ohio – they get hot in the summer, but then there are large chunks of the year where we don’t need to use water for cooling.” Even so, the company’s expansion in Virginia is already causing concern about the availability of water.
To mitigate its impact in such basins, the company also finances dozens of conservation and recharge projects like the one in Chile. It donates recycled water from its data centers to farmers, who use it to irrigate their crops, and it has also helped restore the rivers which provides water-stressed cities such as Cape Town, South Africa; in northern Virginia, it worked to install cover crop farmland which can reduce runoff pollution in local waterways. The company treats these projects like other companies treat carbon offsets, counting every gallon recharged against a gallon it consumes at its data centers. Amazon has in its most recent sustainability report that it is 41 percent of the way to its goal of being “water positive.” In other words, it has funded projects that recharge or conserve a little more than 4 liters of water for every 10 liters of water it uses.
But despite all this, the company’s water stewardship goal does not include the water consumed by the power plants that supply its data centers. This consumption can be as much as three to 10 times the on-site water consumption at a data center, according to Shaolei Ren, an engineering professor at the University of California, Riverside, who studies data center water use. As an example, Ren pointed to a Amazon Data Center in Pennsylvania that relies on a nuclear power plant less than a mile away. That data center uses about 20 percent of the power plant’s capacity.
“They say they use very little water, but there’s a huge water evaporation that happens just nearby, and that’s to power their data center,” he said.
Companies like Amazon can reduce this secondary water consumption by relying on renewable energy sources, which do not require nearly as much water as traditional power plants. Hewes says the company has tried to “decrease” both water and energy needs through a separate goal of working up 100 percent renewable energybut Ren points out that the company’s data centers need power 24 hours a day, meaning intermittent renewables like solar and wind farms can only go so far.
Amazon is not the only company dealing with this problem. CyrusOne, another large data center firm, revealed in its sustainability report earlier this year that it used more than eight times as much water to generate power as it did on-site at its data centers.
“As long as we depend on grid electricity that includes thermoelectric sources to power our facilities, we are indirectly responsible for the consumption of large amounts of water in the production of that electricity,” the report said.
As for replenishment projects like the one in Chile, that too will only go part of the way to reducing the impact of the data center explosion. Even if Amazon is “water positive” on a global scale, with projects in many of the same basins where it owns data centers, that doesn’t mean it won’t still harm water access in specific watersheds. The company’s data centers and their power plants can still withdraw more water than the company replenishes in a given area, and replenishment projects in other aquifers around the world will not address the physical consequences of that particular overdraft.
“If they’re able to capture some of the growing water and clean it and return it to the community, that’s better than nothing, but I think it doesn’t really reduce actual consumption,” Ren said. “It hides very real problems because water is a real regional issue.”
