Digital decarbonisation: sustainability in data centres

The amount of data we produce as a society is growing exponentially. Social media, video streaming, stockpiled images — together these phenomena result in huge quantities of information every day. Much of this information, produced through our smartphones and computers, is held on the world’s digital infrastructure: data centres.

Data centres are physical spaces that house computer servers, digital storage capacity, and the necessary telecommunications equipment to interact with the internet. They facilitate much of the online operations we take for granted.

But the companies operating them are facing growing pressure to make their industry more sustainable. This can be achieved through greater operational efficiency and the use of renewable energy.

Keeping temperatures down

Data centres already account for around 1% of annual global electricity consumption. But there is a 61% increase in data centre traffic every year, according to Professor P.S. Lee, an associate professor of mechanical engineering at the National University of Singapore.

“Southeast Asia is actually one of the fastest growing markets for data centres in the world,” Lee says. The Asia pacific market will be worth $28 billion by 2024, overtaking regions such as North America to become the largest in the world.

Like our planet, data centres have a temperature problem. The equipment they use requires moderate environmental conditions to operate correctly, but as with all computers, it generates excess heat.

This, as well as ambient temperature and humidity, must be dealt with through cooling and air cleaning.

While there are many factors which give data centres a problematic carbon footprint, in Southeast Asia 35-40% of their infrastructure energy consumption comes from their cooling systems, Lee explains.

There are, however, many different ideas circulating on the best methods for keeping temperatures down. Liquid cooling is a particularly strong option.

“Liquid cooling technology is widely used in high-performance and energy intensive sectors, such as cloud computing and cloud gaming, and has long been considered the preferred solution,” Lee says.

Even choosing to operate in countries with lower temperatures needs to be considered. For example, the internet giant Facebook made a point of setting up some of its data centres in colder climates in an effort to limit the costs of overheating.

Reducing carbon footprint

There are three broad factors which affect the carbon footprint of data centres, Lee says.

The first, as already mentioned, is the geographic location. It is more challenging to keep temperature and humidity under control in Southeast Asia than it is in Northern Europe. Additionally, whether or not the data centre is powered by renewable sources of energy or not will impact its sustainability. As such, local power generation plays a role.

The second is IT load: the higher the digital traffic, the higher the required power — and therefore, the higher the carbon footprint.

The third factor is the overall energy efficiency of the data centre infrastructure.

The traditional practice of oversizing the physical infrastructure to support the IT load has a negative impact on energy efficiency in data centres, and by extension, impacts the carbon footprint — “Oversizing results in underutilisation of equipment,” Lee explains.

In order for sustainable data centres to exist, the industry requires a holistic approach. Innovative solutions for cooling, such as the use of seawater and underground storage, must be combined with renewable energy supply and more efficient hardware, Lee says.

Not just data centres

“Truly every industry needs to decarbonise,” says Valerie Choy, Southeast and East Asia Regional Sales Manager for electricity and sustainability group Schneider.

The trend that she is seeing is that the data centre industry in general is at least leading the charge in terms of the use of renewable energy.

“In some countries, take for example Taiwan, they [data centre companies] have even been effecting policy changes to enable corporate renewable energy buying for the rest of the industrial customers,” Choy explains.

Some experts suggest, however, that there is no need to place a special emphasis on data centres. Our real focus should be on the energy grid itself.

“At the end of the day, the whole of society has to decarbonise. We should drive our governments to decarbonise the grid as fast as they possibly can,” argues Ian Bitterlin, a data centre engineering and design consultant, and former visiting professor to the University of Leeds.

The public needs to fight for that, Bitterlin says, and should be prepared to accept lower quality power and higher costs in pursuit of more sustainable practices.

At lot of the focus in the industry is on the use of renewable energy, but Bitterlin sees a number of issues with this.

“We’ve concentrated the sustainability argument for data centres on buying renewable energy, either locally or in remote markets — and then pretended that we’re green,” he says.

While this is legal, Bitterlin believes it is both unethical and misleading.

There are three steps to sustainability, Bitterlin explains. The first step is to reduce consumption; the second step is to improve the process; and the third step is to power it from renewables.

“As an industry, we’re actually doing the whole thing in reverse. We’re pretending that just having a renewable-powered data centre is sustainable, and it’s not — because we haven’t done anything about the other two things,” he explains.

One thing society needs to consider is how much renewable energy we can use and still maintain a stable power grid, Bitterlin says — “What do we do when the wind doesn’t blow?”

Mark Swift is a Scottish freelance journalist and writer based in Paris. His work covers business, technology, European politics, and EU policy. Before writing for 4i-mag, he was a journalist for Young Company Finance Scotland, covering investment in Scottish technology start-ups. Mark's portfolio can be found here: