Data centres are running into a wall of public anger in the United States, and this time the grievance is water. The warehouses of servers that run the internet, and increasingly artificial intelligence, throw off enormous heat, and keeping the chips cool has traditionally meant evaporating vast quantities of it. In 2025 data centres worldwide consumed 222 billion litres of water for cooling, according to the consultancy Rystad Energy. Without new measures, that figure could nearly triple to 644 billion litres by 2030. The industry's answer, laid out this week across reports from Euronews, AFP and others, is that the water problem at least is solvable. The awkward part is what solving it costs.
Nvidia said in June that its newest system for designing and managing AI data centres, known as DSX, can almost eliminate water use at some facilities. It relies on closed-loop cooling, in which liquid circulates through sealed pipes directly past chips that can exceed 80 degrees Celsius, so nothing evaporates away. Microsoft, Amazon Web Services and Meta told AFP they use similar closed-loop systems with no net water loss. It sounds like a clean win. It is not quite.
"There's a pretty direct trade-off between how much water is used and how much energy is used," Andy Masley, an independent researcher who covers data centres, told Euronews. The liquid in those sealed loops still has to be cooled somehow, usually by blowing air over it, and moving air takes electricity. Nvidia softens the blow by letting the coolant run warmer than usual, entering the servers at 45 degrees rather than the 32 degrees typical of closed-loop systems in 2024, so simple fans often suffice instead of energy-hungry chillers. But in extreme climates or during a heatwave, chilled air and evaporative cooling creep back in. Trade water for power and you have not escaped the problem so much as moved it.
Cost explains why the shift is happening at all. "Because water is generally much cheaper than electricity," Shaolei Ren, an engineering professor at the University of California, Riverside, told AFP, companies have little financial reason to conserve it. The real incentive, he said, is public relations. And the pressure is real: more than 500 US counties and municipalities have delayed or banned data-centre projects. In the UK, analysis by the non-profit Foxglove found that two planned facilities alone, at Wapseys Wood and Quest Park, would emit more carbon once running than ExxonMobil did in 2023, each planning its own gas-fired power station. Water UK has called the government's supply forecasts "fatally flawed" for excluding data centres entirely.
The deeper point, made plainly by Tempo and echoed by researchers, is that the water a data centre draws from its own taps is only part of its footprint. Generating the electricity that powers it consumes water too, often more than the cooling itself; in the United States this indirect use can be twice the direct amount, and manufacturing the chips adds still more. Which is why the honest verdict on the industry's water fix is not that it is fake, but that it is partial. Location matters more than any single number: a data centre in a rain-soaked region is a very different proposition from one drinking from a drought-stricken aquifer. Cutting the water a server sips is genuine progress. It is not the same as cutting the thirst of the whole machine.