Status: it’s complicated
As the world catches fire, are data centres helping us improve the climate emergency or making it worse? It’s hard to be precise, Alan Burkitt-Gray finds
Before you beat yourself up about how much the data centre industry is contributing to global warming and the destruction of the planet, here’s a positive statistic from Chris Pennington, director of energy and sustainability at Iron Mountain, the data centre company he has worked for since 1991.
The amount of computing power that the industry collectively provides the world went up by 550% from 2008 to 2018, “but we used only 6% more energy”, he tells me from Oregon.
The trouble is, the industry gives lots of climate-conscious people a bad feeling. They think that working at home, using laptops on their own broadband, is somehow more wasteful of energy than commuting into an office and using the employer’s internet access. Equally irrationally, they think streaming a movie via Netflix to your home TV set is worse in energy terms than heading to your nearest cinema for the evening.
The problem is worsened by the existence of conflicting data from university researchers on the burden the data centre industry puts on the world.
And this year, when we have seen wildfires caused by unprecedented temperatures across the world, the problem has been highlighted by the August report of the UN Intergovernmental Panel on Climate Change (IPCC). We have already seen a rise in global temperature of 1.1°C since the start of the industrial age and it looks like going to 1.5°C, the IPCC said in August.
Glaciers are retreating, to the point at which the Russians are planning a subsea cable in what used to be an iced-up Arctic ocean. The sea level is rising worldwide. Heatwaves – and other weather extremes, such as floods – have become commoner.
The level of carbon dioxide in the atmosphere is higher than it has been for two million years (Homo sapiens has been walking the Earth for only 200,000 years).
How much does the internet, and the data centre industry that drives the internet, contribute to all this – or, indeed, how much can the internet help to reduce the impact?
Some evidence comes from a report in March 2021 of a study at the Massachusetts Institute of Technology (MIT), Purdue University and Yale University on the environmental impacts of internet use.
Maryam Arbabzadeh, a postdoc at the MIT Energy Initiative, who is also a Google scholar, and a co-author of the study, says: “It is great that we are reducing emissions in some sectors. But at the same time, using the internet also has an environmental impact contributing to the aggregate.
“The electricity used to power the internet, with its associated carbon, water and land footprints, isn’t the
only thing impacting the environment. The transmission and storage of data also requires water to cool the systems within them.”
The MIT/Purdue/Yale report notes that to store and transmit all the data powering the internet, data centres consume enough electricity to account for 1% of global energy demand. “Even before the pandemic, the internet’s carbon footprint had been increasing and accounted for about 3.7% of global greenhouse gas emissions,” says the report.
But it’s hard to generalise: data centres vary in the applications they run and in their local climate: data centres in relatively cool Canada, Sweden or Finland have different conditions from ones in India or Kenya.
Output per joule
And, what do you get per joule of energy? That’s a question addressed by Emma Fryer (pictured), associate director of TechUK, a trade association that advises – and lobbies – the government and other public bodies.
It’s like comparing cars, kettles or fridges, she says. At least fridges and some other household equipment have a multicoloured label on them to hint at energy efficiency.
Can you do the same at server level, so you look into the efficiency of the server, she wonders, to get a measure for the energy efficiency of the internet? Well, probably not. “How do you compare a Meteorological Office data centre that’s processing data to forecast the weather with a Netflix one?” she wonders. “Netflix would come out better.”
There is one standard measure that data centre operators quote: PUE, which stands for power usage efficiency. This is where life is easier for telecoms operators, which can measure how much energy in joules is needed to transmit a megabyte of data from a base station to a smartphone.
“The focus is on volumes of data in transit through the network – via the data centre – not the computational power of the servers within the data centre,” notes Matt Peacock, a former group director of corporate affairs at Vodafone who is now a partner at Blurred, a consultancy that specialises in environment, social and governance (ESG) risk, including sustainability, social purpose and corporate transparency.”
Bang for your buck
Peacock adds: “Other types of data centre may have different metrics, of course, but to my knowledge only telecoms operators have that kind of ‘bang for buck’ equation,” he says. “The PUE equation is the standard here – that is, non-operational energy use versus operational energy use – and that is generally what investors [and the] ESG community people look at in the first instance.”
Both Fryer and Pennington are sceptical about PUE in absolute terms, though they acknowledge it’s good for measuring progress over time in a particular data centre. Fundamentally, PUE shows how much of the energy you are delivering to a data centre is used for the IT-like functions, compared with what’s used for other purposes – by, say, the staff’s toasters and microwave ovens.
“Use metrics with care,” says Fryer. “PUE is completely unsuitable, but it’s OK to use for trends.”
Pennington agrees that “PUE is a measure of success”, and he would like to see data centre operators post PUE information on their websites.
Fryer points to another problem in the data centre industry. Not all users store and process their data in big data centres, collectively creating what we now call the cloud. Some still keep everything in-house, in computers that may be well below current standards in energy efficiency.
Pennington highlights a further challenge – when customers bring their own IT equipment into a data centre building and plug it into the power supply. “Hyperscale operators own and operate the systems for their own purposes,” he says. “They have a great deal of control.” But a colocation company has “no idea” what the efficiency of customers’ equipment might be.
Fryer agrees: old computers are a problem, potentially an unknown problem. “On-premise equipment is generally very efficient,” she notes, speaking from her home in the rural north of England. (Whenever I have seen her in person, she is usually carrying her cycling helmet, having travelled by train from home and biked to the meeting from the station.)
So where are we going in the data centre business? Pennington, who notes that he is “the entire team” at Iron Mountain focusing on energy efficiency, says that data centres have an economic incentive to use as little power as they can.
“We have a commitment to use 100% renewable power 100% of the time by 2040. That’s our goal.” Although he adds, wryly, that Google’s target is a bit more advanced. “Only ourselves and Google commit to a target. They’re Google, so they aim at 2030. We gave ourselves 10 years extra because we’re not Google.”
The challenge in the industry when you build a new data centre, “often in response to a signal from the market”, he says, is that lead times for equipment and electricity supplies can be long, he says. “Efficiency improves over time, but it starts off terrible. It is not a case of build it and they will come.”
He sees a move towards better methods of cooling. “Blowing air around a room is massively inefficient.” Even the fans contribute a significant load to the power supply.
Another of the challenges is that it’s hard to find uses for the heat generated, what could be regarded as waste heat. “It’s not hot heat, just 95°F,” he says. That’s 35°C. “You can’t even take a hot shower with that.” But using waste heat “has to be where we go”, though even pumping it out for district heating actually adds to the energy load.
A move to edge data centres “has potential to be efficient”, says Pennington. “This would be moving to where the data is acquired – from cars, banks and so on. This can create [networks that are] smaller, more nimble, more contained and more compact – that’s an opportunity for the industry.”
And as the industry expands, creating more efficient data centres in new buildings will help, he hopes. The ideal is “constructing new data centres to a green building standard”, he says. “Adopting a green building standard means not creating bad data centres.”