Click HERE to read part one of this two-part series on the need for green data centres and the obstacles standing between the industry and true decarbonisation.
The “green data centre” doesn’t go far enough. Until now, access to renewable energy, water and power efficiency, and use of techniques like free cooling have been enough to qualify a data centre as sustainable. Low PUE and net-positive water usage have allowed data centre operators to advertise their ESG bonafides.
However, some industry experts argue that these metrics are out of step with the industry’s very real and present need for more meaningful emissions reductions. “There is no truly green data centre until we achieve deep decarbonisation,” says Helen Munro, Head of Environment & Sustainability at Pulsant. “It’s important to recognise that this is a journey right now, and not a reality.”
What makes a green data centre?
“It’s often assumed that the greenest data centres are new builds. A new build can be designed to be as efficient and self-sufficient as possible, reducing the reliance on external power sources and promoting energy efficiency,” Munro explains.
However, there’s a problem with building new infrastructure. No matter how energy efficient your data centre is, construction is an inescapably carbon-intensive activity. “We need to balance the efficiency gains of a new building with that impact and consider the improvements that we can make to existing assets,” she argues.
There’s already some effort in the industry to lengthen upgrade cycles. Google (along with other hyperscalers) has started using its servers and IT equipment for significantly longer amounts of time. Between 2021 and early 2023, the company extended the lifespan of hardware like servers from four to six years. The move, in addition to saving Google as much as $3.4 billion per year, reduces the amount of e-waste considerably.
The site selection question
Where you put a data centre also has a meaningful impact on its environmental impact. Powered by local energy sources, plugged into a local grid, drawing water from the local supply, and built using local materials, codes and techniques. Regional power grids often have very different carbon intensities. “Data centres in areas of the Nordics, for example, are benefitting significantly from high availability of renewable power, as well as cooler climates which facilitate lower infrastructure power consumption,” Munro adds. “A well-sited data centre can also feed into local district heat networks, thereby avoiding emissions.”
Optimising data centre location requires compromise on climate
However,the problem is that we can’t put all our data centres in Norway. Increasingly, as artificial intelligence, IoT and 5G increase localised computing, there’s more demand for lower latency connections. “It can be important for clients to have access to a data centre which is local to them,” says Munro. She adds that “data centres with a local focus should fall back on buying power in the greenest way they can; recognising that approaches such as physical PPAs can give stronger renewable power additionality than a 100% renewable tariff and be ready to engage with opportunities such as heat networks when they become locally feasible.”
In short, there are many factors that affect a data centre’s sustainability that lie outiside the direct control of the company that builds it. These factors include “not only the local power grid and climate, but the impacts of the upstream supply chain for infrastructure, hardware and services,” Munro explains. She emphasises how critical it is that organisations committed to building and operating greener data centres “develop a robust plan to maximise their positive influence and recognise that no site can be entirely sustainable unless the wider ecosystem is, too.”
Specifically, she adds that “Organisations should also ensure their concept of ‘sustainability’ includes the impacts beyond their site boundaries, and goes beyond only the carbon footprint.” Munro points out that hydrated vegetable oil (HVO) fuel can result in emissions reductions, its production has also been linked to an increased risk of deforestation. “Focusing on environmental sustainability beyond reducing carbon emissions and involving initiatives to protect local ecosystems and wildlife, will help organisations reinforce their focus on becoming greener,” she notes.
Where do we go from here?
Is the green data centre a myth, then? Can data centre companies—even those taking a holistic view of their entire environmental impact—actually build facilities that have a light enough environmental footprint to avoid contributing to the climate crisis?
Munro argues that “We need to consider efficiency in relation to the value of the computing workloads” that data centres host. She argues that “organisations generate and store huge amounts of data every day that is of little-to-no-value to them; so even using the greenest of data centres, this is a waste of power and hardware resources.”
It’s a complex issue with no easy solution. However, the first step is changing the conversation around what constitutes a green data centre. Operational efficiency is no longer enough to call a data centre green. The entire project, including its impact up and down the supply chain, needs to be considered holistically if meaningful steps are to be taken to reduce environmental impact.
A recent report by the World Bank argues that “Addressing the climate footprint of data centres requires a holistic approach, including design, manufacturing, procurement, operations, reuse, recycling, and e-waste disposal. Beyond increasing energy efficiency and reducing carbon emissions, these steps can reduce e-waste and limit the data centre’s environmental footprint throughout the data centre lifecycle.”
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