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Powering the beast: why we shouldn’t worry about the Internet’s rising electricity consumption

13 Jan 2021 James McKenzie
Taken from the January 2021 issue of Physics World. Members of the Institute of Physics can enjoy the full issue via the Physics World app.

The Internet will use a fifth of all the world’s electricity by 2025 – and that’s no bad thing, says James McKenzie

server-room datacentre
Fighting fit Data centres, which power the Internet, are incredibly efficient in terms of energy use. (Courtesy: iStock/Kwarkot)

I recently went on a canal holiday, drifting on a hired narrowboat through the pretty Staffordshire countryside. Travelling by canal is the fastest way to slow down, they say, because the sedate pace, tranquillity and wildlife all give you time to think. As I meandered past factories, potteries and mines, I started to reflect on the Industrial Revolution and the reasons why the British canal network was built.

From today’s perspective, canals seem cataclysmically slow – you’re limited to a top speed of four miles per hour and it takes about 20 minutes to get through a lock. But back in the 18th century canals were a spectacular breakthrough, allowing companies to move raw materials and goods at low cost. A single horse could tow a boat with 50 times as much cargo as it could pull by cart.

The canal heyday didn’t last. Soon came steam engines and railways, which were much faster. They in turn were usurped by cars, lorries and trucks, with the road network providing an even faster, cheaper and more convenient way of delivering goods and services, driving productivity and economic growth. But every mode of transport – even canals – faced initial opposition to their creation, routing and impact.

Misleading sensationalism

Today’s modern communication infrastructure – the Internet – has also suffered. I’ve seen headlines like “Silicon Valley’s dirty secret”, “How to stop data centres from gobbling up the world’s electricity” and “How viral cat videos are warming the planet”. One old favourite is “Google searches can generate the same amount of CO2 as boiling a kettle”, even though the maths is out by several orders of magnitude and it’s wrong to assume that energy consumption is directly related to CO2 emissions.

I’ve read articles about web-server data centres, such as those used by Google and Facebook, being blamed for 2% of greenhouse-gas emissions, which is about the same as air travel. The BBC website even had a recent story suggesting we should send fewer e-mails to “save the planet”, though it added it won’t make much difference as the infrastructure to send e-mails – your laptop, the WiFi and the network itself – are all “on” anyway.

20% of the world’s total electricity consumption may be used by the Internet by 2025. Some may find this appalling, but to me, it’s absolutely fine.

The beauty of e-mails is they are so quick and cheap. In the UK it costs 85 pence to post a letter (plus envelope, paper and the effort to get to the post box) whereas an e-mail costs almost nothing (and has a lower environmental impact) and doesn’t take two days to arrive. Of course, when something is nearly free, people consume more of it. Known as the Jevons paradox, it was first applied in the 1800s to coal, but communications are price-elastic too.

According to a recent report from KTH Royal Institute of Technology in Sweden, about 10% of the world’s total electricity consumption is currently used by the Internet. The figure has risen from 8% in 2012 and may reach 20% by 2025. Some may find this appalling, but to me, it’s absolutely fine. The Internet, after all, is driving the next step in productivity and economic growth plus it underpins carbon reduction across the economy. And don’t forget that if all of us drove electric vehicles, we’d need twice as much electricity as now.

Even data centres – those buildings filled with servers and hard disks that are the physical manifestation of cloud computing – are doing a good job. Yes, they require lots of energy: a large centre typically consumes more than 30 GWh per year and has an annual £3m electricity bill – roughly 60% of its running costs. But the operators are therefore laser-focused on energy efficiency. What’s more, over 75% of energy used by the UK’s 450 commercial data centres is certified 100% renewable.

So-called “hyperscale” data centres, which emerged when firms like Facebook, Amazon and Google needed fleets of a quarter of a million servers or more, led to Facebook founding the Open Compute Project in 2011 to share hardware and software solutions to make computing more energy-efficient. The member firms (there are about 200 today) realized it made no sense to use off-the-shelf hardware. Instead, they developed “bare-bones” servers, in which video hardware and connectors were stripped out (as no display was needed) and blinking lights were removed (there was no-one to look at them).

The best “hyperscale” data centres have whittled their power usage efficiency (PUE) down to about 1.2.

So whereas conventional data centres have a power usage efficiency (PUE) – total energy needed divided by energy for computing – of 2.0, the best hyperscale facilities have whittled this figure down to about 1.2. Google even boasts a PUE score of 1.12 on average for all its centres, which is not far off a perfect 1.0. Improvements in cooling technology have helped too: Facebook’s Lulea data centre near the Arctic Circle in Sweden uses outside air for cooling and runs on hydroelectric power.

Facebook, Google, Apple and others have all committed to using 100% renewable energy (though rivals such as Baidu, Tencent and Alibaba have not). Indeed, Google is the world’s largest corporate purchaser of renewable energy (and carbon neutral since 2007) and pledges to be carbon free by 2030. Microsoft has even promised, by 2050, to have removed from the environment all the carbon it has directly emitted or consumed since it was founded in 1975.

Greenpeace IT analyst Gary Cook paints a less rosy picture, saying that only about 20% of the electricity used in the world’s data centres is so far renewable, with 80% of the power still coming from fossil fuels. That may be so, but given that Internet companies are so focused on efficiency and pay more to have clean electricity (and deliver carbon-reduction services) we need to do a lot more to make electricity carbon free in the first place. That – and not headlines about cat videos warming the planet – is where the focus should be.

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