Thirsty data centres are making Europe’s dry summers even drier

MADRID – For more than a year,

Spain has been struggling with drought

that has sent water levels in dams below historical averages, prompting local officials to tell residents not to water their gardens and to turn off taps at night to guarantee supply during the day.

The situation is particularly hard for farmers. The central region of Castilla La Mancha, which produces a quarter of all Spanish grain, is expected to lose 80 per cent to 90 per cent of 2023’s harvest, and water restrictions loom large.

Yet in Talavera de la Reina, a small city tucked among the region’s yellowing barley and wheat fields, Meta Platforms is planning to build a €1 billion (S$1.5 billion) data centre.

Meta expects the facility to use about 665 million litres of water a year, and up to 195 litres per second during “peak water flow”, according to a technical report.

Enthusiasm about the jobs the project is expected to create (1,000 in total, about 250 of which will be permanent) is now being weighed against heightened concerns over water.  

“People don’t realise that ‘the cloud’ is real, that it is part of an ecosystem that consumes many resources,” says Ms Aurora Gómez, a spokesman for Tu Nube Seca Mi Río (“Your Cloud Dries Up My River” in Spanish), a group created to fight the construction.

“People are not aware of the amount of water that goes into watching a kitten meme.”

We tend to think of the Internet as immaterial, but websites exist in the real world as rows of servers that never turn off, filling data centres that need to be cooled to prevent technical failures.

Operators such as Amazon, Google, Meta and Microsoft use a wide array of systems to do this; the most energy-efficient ones – such as cooling towers – typically evaporate water to chill the air circulating in the buildings.

With drought spreading around the globe, battles are emerging between data centre operators and adjacent communities over local water supplies in places such as Chile, Uruguay and parts of the south-western United States.

In the northern Netherlands, public outrage erupted in 2022 when a local news outlet reported that a Microsoft data centre complex was consuming more than four times as much water as the company had previously disclosed.

Some of the cooller, wetter hubs in northern Europe, such as Ireland and the Netherlands, have blocked the development of new data centres because of concerns about energy consumption, leading companies to start looking farther afield.

Operators of hyperscale data centres, those with more than 5,000 servers, are migrating to places where water is plentiful, such as Norway, but also to drought-prone places like Italy and Spain where energy is cheaper – and where extreme heat is becoming the norm.

While data centres have faced scrutiny over their electricity use, little is known about their water consumption –including by tech companies themselves.

A survey conducted in 2022 by the Uptime Institute, a consulting firm, found that only 39 per cent of data centres even tracked their water use, a 12 percentage point drop from 2021.

Tech companies in the past have refused to disclose information about individual centres’ energy and water consumption, claiming that such data was a trade secret.

Over the last couple of years, Google, Meta and Microsoft have started publishing their total water use across their operations, but they do not break the number down by business unit nor use standardised metrics.

Bluefield Research has estimated data centres use more than a billion litres of water per day, including water used in energy generation.

Governments are beginning to demand more information.

Beginning in March 2024, the European Commission will require operators to report wide-ranging data about their energy and water use to the public.

In Britain, the Thames Water utility is investigating the amount of water that data centres are using in London and may adjust its pricing model for water-intensive businesses depending on the findings.

Identifying which water-intensive clients are data centres has not been easy, says Mr John Hernon, who is heading up the probe.

Operators often use shell companies to apply for planning permissions, and a data centre can look like any large warehouse or factory from the outside.

Dr Arman Shehabi, a researcher at the Lawrence Berkeley National Laboratory in California best known for a landmark paper on energy consumption at data centres, thinks the facilities could contribute to scarcity as droughts become longer and more intense.

Part of the problem, he says, is that data centre operators “are generally the last ones to the table to ask”, straining the system by asking for access to scarce water after agricultural interests and local communities have already come up with a plan.

“Everybody is going to feel that,” he says.

Companies say data centres are getting more energy-efficient, but the increase in overall demand for computing power is outpacing such gains.

The race to build large language models used in generative artificial intelligence (AI) has created a surge in demand for more powerful processors.

The specialised chips required for AI – broadly known as accelerators – emit so much more heat than general purpose chips do that data centre operators are having to rethink their cooling systems entirely, says Mr Colm Shorten, a data centre sustainability expert at real estate investment firm JLL.

Dr Shaolei Ren, associate professor of electrical and computer engineering at University of California, Riverside, has conducted research estimating that training GPT-3 in Microsoft’s US data centres directly consumed 700,000 litres of water in about a month – not including the indirect water use associated with electricity generation.

The team has also calculated that every short conversation of 20 to 50 questions and answers with ChatGPT represents about 500ml of water.

“Microsoft is investing in research to make large systems more sustainable and efficient, in both training and application,” said a Microsoft spokesman in an e-mailed statement. “Climate change is a real and urgent challenge, with increasingly severe impact on our businesses, our communities, and the ecosystems that sustain them.”

OpenAI did not respond to requests for comment.

Mr Shorten says that over time, data centres will need to radically change the way they dissipate heat.

The gold standard, he says, is a process called immersive cooling, in which servers are bathed in a special fluid that transfers heat from the chips.

For now, operators are likely to opt for a hybrid model, wherein a high-performance section of the data centre will be liquid-cooled while the rest will continue to use air conditioning, he says.

Amazon Web Services, Google and Microsoft have all made water stewardship pledges, promising to use more non-potable and recycled water and to replenish more water than they consume operationally by 2030.

This is the equivalent to offsetting carbon by planting trees – something that looks good on paper but may not directly benefit the communities affected by data centres, because water may be replenished only in places where it is easy to do so.

In Spain, Meta has pledged to “restore more volume of water than is consumed at the facility, through hydrological restoration projects”, but it has not yet determined whether water restoration efforts will affect Talavera.

It says it recycles water used in its facilities and has reduced the controlled humidity level in data halls where it uses direct evaporative cooling, cutting water consumption by 10 per cent to 65 per cent across those facilities.

As the authorities experiment with provisional measures such as covering one of the town’s central streets with a canopy of umbrellas to protect locals from the sun, Ms Gomez from Tu Nube Seca Mi Río is sceptical that tech’s promises to help will have any positive effect on Talavera.

The water replenishment plans fulfil two objectives, she said: “To look good in the eyes of the general public, and to win over a local environmental group.” BLOOMBERG