Data centres are expected to see explosive growth in the next few years, but the industry is under fire for its water usage. Huw Morris reports
American writer Maggie Stiefvater summed up the irony perfectly: “You could write a book about things you can’t find online.” The information communication sector is doing everything to prove her wrong.
Forecasts suggest the industry will see explosive growth in the next few years. According to consumer data specialist Statista, there were 4.66 billion active internet users worldwide – 59.5% of the global population – as of January 2021. Of this total, 92.6% (4.32 billion) accessed the internet via mobile devices. Technology conglomerate Cisco predicts that 5.3 billion people will have access to the internet by 2023, with 29.3bn devices online by 2030, while the International Energy Agency estimates internet traffic will double by next year.
This massive thirst for information means a massive thirst for water. Data centres, vital to meeting this demand, are huge quaffers of water due to the electricity generation or cooling they require. In the US they consumed 660bn litres of water in 2020, according to the country’s Department of Energy. Technology giants, in particular, are major guzzlers: Google gulped down 15.79bn litres of water in 2018, while Microsoft swallowed 3.5bn litres – mostly through their data centres.
The scale of the problem
“Considering how much data is stored in data centres, it is ironic how little data is available about how they operate,” says David Mytton, a researcher in sustainable computing at the Uptime Institute, Imperial College London. Most people start with energy when focusing on data centres’ environmental impact, he says – an area that has seen major shifts to renewables during the past decade. Large data centre operators such as Amazon, Google and Microsoft are regularly in the top 10 renewable energy buyers each year.
Mytton points to figures published last year in Science revealing that, between 2010 and 2018, the number of servers worldwide increased by 600%, network traffic by 1,000% and storage capacity by 2,500%. Yet energy consumption only grew 6%, largely due to the migration of data to cloud computing, which manages 40% of servers. “The same cannot be said for water consumption, which is a decade behind energy in understanding, transparency and progress,” he argues.
“We have to be careful when comparing resources like energy and water, because the sustainability goals are not the same. With energy the goal is zero carbon, but zero water is not the right approach. Data centre water consumption is dependent on the region, because that dictates which cooling technologies can be used. In cooler regions, zero water can be achieved and should be the goal, because free airflow cooling is possible for some, if not all, of the year. But in many hot regions, this is simply not viable. That’s important to understand, because not only is a large part of future demand growth going to come from hot regions like Africa, South America, India and Asia, but global temperatures are also going to increase due to global warming in general.”
“Considering how much data is stored in data centres, it is ironic how little data is available about how they operate”
Mytton states that less than a third of data centre operators use metrics for measuring water usage, with the issue a low priority for most. Facebook is one of the few global companies to report water usage effectiveness (WUE), a metric for tracking annual site consumption; Google and Microsoft simply publish total water consumption. “Unfortunately, you can’t actually use Facebook’s infrastructure in the same way you can with Google and Microsoft – it’s all for their own applications.
“Understanding the source of water is also necessary to analyse water metrics. Some would argue that, where water is used, the goal should not be zero water but zero freshwater. If water is recycled or reclaimed, its impact is not the same as if all the water is drawn from municipal or freshwater sources. However, this is not revealed by consumption metrics or WUE. The relative water stress of a region is also not represented in these figures.”
This is about to change, according to Kerry Stares, a partner and director of responsible business at Charles Russell Speechlys. “The direction of travel is very clear – businesses will be increasingly required by regulators, investors and customers to disclose data and information about their environmental sustainability, including use of water and other resources,” she says.
“The UK government, for example, has committed to make it mandatory for businesses to report on their climate risk in line with the recommendations of the Taskforce on Climate-Related Finance Disclosure. Climate change will create significant water-related risks and data centres will need to be astute to, and increasingly transparent about, how water risks may impact their operations and supply chains.
“It is essential that water usage is not considered in isolation”
“Those taking conscious and proactive steps to manage water consumption responsibly, and who can demonstrate that through disclosure, will be at the front of the line for capital and custom.”
The industry’s response
Some in the data centre industry are taking water very seriously. Google, for example, announced a target to “replenish 120% of the water we consume” on average across its offices and data centres. “At data centres, we’ll identify opportunities to use freshwater alternatives where possible – whether that’s seawater or reclaimed wastewater,” the company’s chief sustainability officer Kate Brandt has said. “When it comes to our office campuses, we’re looking to use more on-site water sources, such as collected stormwater and treated wastewater, to meet our non-potable water needs like landscape irrigation, cooling and toilet flushing.”
US data centre owner CyrusOne is restoring 120% of the water used at its two biggest facilities in Arizona and Texas – both regions of high water stress. It says the sector must take responsibility for water consumption not only because it is the right thing to do, but also because failure to do so could result in “significant damage to the industry’s reputation” and future growth.
“Water scarcity is a local issue,” says Kyle Myers, CyrusOne’s senior director of environmental health, safety and sustainability. “If you operate in an area where water is plentiful, it’s probably not a big issue. But if you operate in an area where water is not as plentiful, that’s where we have to look at best practices within the industry.”
Myers admits that customers, shareholders, staff, board members and communities are all pushing on resources. “For us, the story started with moving into a market where there was water scarcity; the local planning commission said, ‘use all the power you want, but you can’t use water’. That made us start thinking about what design might work.
“There’s been an increased focus, especially in the last two years, from the customer base. It used to be climate change and that’s all you’d hear. Now we hear about water scarcity – we just got a four-page questionnaire with maybe 40 questions just on water from a potential customer and a large company. So we know it’s top-of-mind for a lot of organisations.
“Moving toward less water consumption per kilowatt hour of power delivered to servers – the WUE metric – has got to be the focus. But it’s not just the water on-site, it’s also the water used to make the electricity. One great thing is renewable power sources, like solar panels and wind power. The water consumption on those is zero, at least according to the accounting methods. If you’re able to pair renewable power with zero or low-water cooling, you can get to zero water consumption across cooling, as well as carbon-free power.”
Myers says the issue is a moving target, particularly as the industry grows 10%–15% annually. “If you assume we’ll continue that line of growth in the next 20 years, by 2040, 80% of the data centres won’t even have been built. There’s huge opportunity to leverage technology and innovations and see what others are investing in. That’s going to be the future of how we make water scarcity a non-issue from an environmental perspective.”
Technology lawyer Mark Bailey, a partner at Charles Russell Speechlys, predicts that the focus on water as a precious commodity will increase, and contractual metrics could emerge to measure its consumption.
“As part of an overall energy and resource efficiency programme, it is essential that water usage is not considered in isolation, as the overall efficiency of the data centre in terms of power and energy consumption can be beneficially affected by water use,” he says. “The overall water lifecycle in a data centre, including steam emissions, may generate measurable benefits for a local community around the data centre for water recycling, provided the right tax incentives are created and there is a local demand to fulfil.”
Huw Morris is a freelance journalist.