Green IT: how Apple and other big cloud-computing firms are making datacentres more sustainable

“The project will not only supply renewable energy for our datacentre [in nearby Reno] but also provide clean energy to the local power grid, through a first-of-its-kind partnership with NV Energy. When completed, the 137 acre solar array will generate approximately 43.5m kilowatt hours of clean energy, equivalent to taking 6,400 passenger vehicles off the road per year,” Apple wrote in a recent statement to the Nevada public utilities commission.

This means computer server farms, the backbone of every email, document and internet search, can be made more sustainable. 88 per cent more sustainable, to be precise. And clean energy is only a small part of the equation. According to a new report by researchers at Stanford University, Northwestern University and the Lawrence Berkeley National Laboratory, published earlier this summer in Nature Climate Change, server farm greenhouse gas emissions could be cut by 80 per cent if companies used state-of-the-art IT equipment. Because datacentre cooling consumes large amounts of energy as well, an additional eight per cent of greenhouse gas emissions could be cut if companies moved their server farms to cooler locations.

That’s exactly what some major companies are doing. “Big cloud-computing companies like Google, Facebook, Yahoo and Apple have consolidated sustainability matters so there’s one group, one responsibility,” says Jonathan Koomey, a research fellow at the Steyer-Taylor Center for Energy Policy and Finance at Stanford University and a co-author of the study.

“Moving towards server farm sustainability is not always cheaper, but these companies still see it as beneficial because they can put a strategic issue behind them.”

According to Google spokeswoman Kate Hurowitz, it can be cheaper too: “Our datacentres use 50 per cent less energy […] We do this by building extremely efficient facilities that measure power usage, manage airflow, adjust the thermostat and use free cooling. Over the years we’ve saved over $1 billion in energy costs.”

Google now puts information about its server farm efficiency online, while eBay publicly documents all energy and sustainability data. “And Facebook recently built its first data centre outside the US in a Swedish town where it can get all its energy from renewable energy,” says Greenpeace IT analyst Gary Cook. With the town, Luleå, located near the Arctic circle, Facebook’s server farm will benefit from the cold weather too.

But 80 per cent of today’s server farms belong to companies whose main business is not computing, and these datacentres often operate at a leisurely and wasteful pace. “Energy use is a secondary concern for them,” says Eric Masenet, an associate professor of mechanical engineering at Northwestern University and a co-author of the study.

“The datacentre’s IT hardware and infrastructure are in the domain of IT engineers, who are typically not the ones who pay the electricity bill, so there’s less direct incentive on energy efficiency.” Study co-author Arman Shehabi of the Sustainable Energy Systems Group at the Lawrence Berkeley National Laboratory adds: “It’s not unusual to find old servers in these datacentres that are still plugged in, but not providing computational services anymore. We call these zombie servers. They’re just taking up space, consuming electricity to stay on, but there’s just no incentive for the IT department to start poking around their datacentre to figure out which servers they can unplug.”

A manufacturing company can fly below the radar when it comes to server farm efficiency. But, reports Cook, even Fortune 500 companies that don’t prioritise sustainability are beginning to join the trend. “Many now opt to have Google run their IT by using Google’s cloud rather than Microsoft Office. That’s good news, because the cloud is more energy-efficient.”

And the companies that opt to keep using their own server farms? If they fix the IT-utilities divide, revolutionising datacentre sustainability is both easy and cheap, says Masenet. “Most datacentres can save lots of energy simply by running at a higher temperature set-point: the IT equipment can handle it. And they can keep hot and cold sides of server aisles segregated, which for some datacentres can be as easy as installing baffles of plastic to avoid mixing of hot and cold air.”

Still, every search we perform, every document we save uses energy and thus contributes to greenhouse gas emissions. In fact, personal gadget use generates more emissions than server farms. So how can an ordinary computer user contribute to sustainability?

“Turn off your home internet modem when not needed, since it’s constantly consuming power whether one is using it or not. Streaming data via cellular networks to mobile devices is particularly energy-intensive, so be mindful of how much cellular data you consume. Using the WiFi mode on your mobile devices is a more energy efficient option,” says Masenet.