Thirsty data centres need not bleed the UK dry, but transparency is key
Cooling system on the roof of Telehouse South data centre in London, 2024 (Credit: PA Images / Alamy)
4 min read
As the UK bets its future on artificial intelligence, one piece of critical infrastructure has been thrust into the spotlight: the data centre.
The government’s commitment is clear, with the UK-US Tech Partnership set to channel some £31bn into digital infrastructure. This is for a very good reason: data centres are essential infrastructure for any kind of digital service, from AI down to online banking and cat videos. They are the bedrock upon which the digital economy is built.
There’s a catch, though. Data centres use vast amounts of resources, particularly energy and water, to operate and prevent key components overheating. And as data centres pivot towards AI training and inference, they are becoming ever more resource-hungry. That’s already sparked widespread concern that they could induce water shortage and environmental damage.
But how serious is the threat? It’s worth putting the scale of the problem into proportion.
The water supply in England for 2023-2024 was about 14.6 million cubic metres (m3) - or around 14.6 billion litres – per day. There is no central statistic of data centre water use and estimates vary widely. One estimate from the International Energy Agency places the daily requirement for an average 100 Megawatt (MW) data centre at around 2,000 m3. The total estimated capacity of data centres in the UK in 2024 was 1,600 MW, so if we assume that this usage pattern holds everywhere, that implies 32,000 m3 of water a day going to the UK’s data centres.
The reality might be better than even these assumptions suggest. A recent industry survey of data centre operators found that almost two-thirds of data centres in the UK use less than 10,000 m3 of water in a year, let alone daily – less than a typical leisure centre could be expected to need.
To put that in context, households account for the lion’s share of water consumption, approximately 8 million m3 a day in 2023-24, while the latest available statistics for the agricultural sector suggest usage of 411,000 m3 of water per day in 2018.
That doesn’t mean there’s nothing to worry about. Many areas in England are water-stressed, and if no action is taken, demand for water in England and Wales could outstrip supply to the tune of 5 million m3 every day by 2055 – a catastrophic eventuality.
Data centres often cluster, too, particularly in London and the South East, meaning they can put strain on local water networks – even if, on the national scale, water usage seems modest. Data centre operators are also not mandated to disclose water usage, making it difficult for the Environment Agency to build an accurate picture for forecasting potential shortages.
But this could be a manageable problem. As the workloads placed on data centres have evolved, so too has cooling technology. There are a range of alternatives to traditional cooling being used – ranging from closed-loop systems that circulate and recycle coolant; to ‘direct-to-chip cooling’, which draws heat directly off specific components through cooled plates; to ‘immersion cooling’, which submerges server components into a non-conductive dielectric fluid.
These approaches can significantly reduce or even eliminate data centres’ water needs for cooling. These are not fringe ideas, either; over half of UK data centres are already using waterless cooling systems. Innovation continues apace, too: some even further-out plans include submerging data centres on the seafloor or even sending them into space.
Bottom line: data centres need not bleed the UK dry. Thanks to rapid advances in cooling, the sector’s water footprint seems more manageable than often feared. But to prevent a manageable problem becoming a serious problem, we need transparent monitoring of water use, joined-up digital and environmental policy, and a commitment to making Britain’s digital backbone a world leader in water efficiency.
Sam Robinson is head of AI at the Social Market Foundation
