Water efficiency of English datacentres scrutinised in TechUK report

A report into commercial datacentres’ water usage in England suggests the sector is more efficient and less water-intensive than previously thought, thanks to advances in cooling technologies.

The survey, carried out by UK tech trade body TechUK in collaboration with the Environment Agency, set out to assess the environmental resources consumed by the datacentre industry in England, with a particular focus on water use. 

TechUK gathered data from 73 sites across England, including more than 50 in the Water Resource South East region, and its findings showed that modern cooling systems are less reliant on potable water to keep servers from overheating than perhaps thought.

According to the results, 51% of surveyed sites use waterless cooling systems that require no additional water beyond the standard use of a commercial building. Out of those facilities that do use water, most employ hybrid systems combining air, water and refrigerant-based heat rejection, with only 5% relying entirely on water-based cooling.

These figures are significant because the datacentre industry has often been criticised for a lack of transparency around its environmental footprint. In fact, when compared with broader industrial consumption, datacentres account for only a small fraction of water use. The report notes that 64% of sites consumed levels of water similar to that of a Premier League football club over the course of a year.

One key conclusion is that datacentres have steadily become more water-efficient, largely due to technological innovation. Methods such as liquid cooling and direct-to-chip cooling are reducing or eliminating reliance on potable water. This trend is especially important as the UK government pushes for rapid expansion of datacentre capacity to meet the growing demands of AI-driven computing.

Luisa Cardani, head of the Datacentres Programme at TechUK, said further innovation in cooling is likely to continue. “A lot of the datacentre operators for newer facilities chose to move away from any water use where possible, and move to waterless cooling or hybrid systems,” she said. “That trend has continued because, as more and more data has become available around where there is water scarcity in England, they need to be efficient with their resources.”

The report also makes recommendations for government and industry, including the development of standardised but flexible cooling requirements for AI-ready servers. It calls for early coordination between datacentre developers, local authorities and water suppliers to ensure water demand is aligned with local supply capacity through clear connection agreements.

“Water companies would have this data. So, the question here is whether regulation is necessary,” Cardani added. “As our survey shows, a lot of these companies actually measure how much water they use, which itself is a very good thing, of course. As part of our recommendations, we call for all of the sector to do this.”

Richard Thompson, deputy director for water resources at the Environment Agency, said the report demonstrates that “UK datacentres are utilising a range of cooling technologies and becoming more water conscious”, adding: “It is vital the sector puts sustainability at its heart, and minimises water use in line with evolving standards. We are working with industry and other regulators to raise these to secure the best outcomes for our environment and our water supply for future generations.”

Despite its positive outlook, the report acknowledges its own limitations. The sample size of 73 sites represents only a fraction of the UK’s 477 datacentres, with all data provided voluntarily and without external validation. Most participating sites were located in Greater London and the South East, and the study focused only on large commercial facilities, excluding smaller operators.

According to Peter Judge, senior research analyst at Uptime Intelligence, this lack of transparency is no surprise. “Datacentre operators don’t really naturally give up information,” he said. “They’re operating in a world where they’re focused on their clients. Their clients expect a sort of level of privacy and so forth. Their default position is to not give information unless they absolutely have to. So, I think it will be forced upon them by legislation, rather than them doing it willingly.”

Judge argues that disclosure could ultimately benefit datacentre operators, particularly if they are classified as critical national infrastructure. “A lot of banking services and health services depend critically on datacentres, but you can’t say all datacentres are critical to the functioning of the country, some of them are simply storing personal videos.

“In other words, when legislation happens, it automatically has to demand information from the providers for there to be a benefit to being classified as critical national infrastructure, which might mean that you get exemptions from some of the energy efficiency or water usage demands.”

Uptime has previously criticised the sector for being overly secretive. “Datacentre operators have generally been too complacent, too secretive and when asked about environmental impact, they have been much too inclined to issue little lectures about how datacentres are really important, so we should all stop worrying,” Judge said.

He added that operators should engage more proactively with policymakers: “One of the things that Uptime is talking to operators about is the need to engage proactively with the people that are setting the legislation to try and make sure that the legislation is made with an actual understanding of how the sector works.”

Judge also warned that efficiency gains must be viewed in the context of rapid industry growth. “The industry likes to concentrate on efficiency rather than totals, but totals is how people set policies at the national level,” he said.

“If a big cloud provider improves the efficiency of its datacentres by 10%, but it has expanded the total capacity it’s using 10-fold in that time, it's basically using 10 times the power, just with a little bit more efficiency.”

The government has already announced significant investment in expanding datacentre capacity across the UK by 2030.