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Are gas-powered datacentres all hype and hot air?

As concerns about how the proliferation of datacentres will affect electricity supplies continue to be raised, some are experimenting with natural gas as an alternative energy source. But is it a viable, long-term solution?

The government is under pressure to get a firm grip on how much energy our increasingly digital economy consumes, as debate continues to rage about how big a drain the datacentre industry is on the UK’s energy supplies.

The matter was brought into sharper focus in late February 2018, following the publication of a research paper by cross-party think tank, Policy Connect, on the impact of society’s creep towards digitisation, both from an energy cost and carbon emissions perspective.

The report argues that, while technology has a role to play in helping the UK transition to a low-carbon economy, policy-makers need to take stock of how much energy is used to power the digital economy now.

That includes the energy powering internet-connected devices, data transmission networks and the datacentres used to deliver the online services people rely on each day to do their jobs, run their homes and while away their leisure time.

“To date, the energy cost and carbon impact of the digital economy has not increased to the epic proportions once predicted. High energy bills, new efficient technologies and regulations have kept the proportion of electricity used by ICT products and services in check,” the report states.

“However, there is a risk that with a growing dependence on connected devices and digital technologies, energy efficiency gains may slow or even stall.”

Energy consumption needs to be measured accurately

To guard against this happening, the report makes a case for developing better methods for measuring the energy use of datacentres, networks and connected devices, as there is “no way to systematically measure energy use on a national level” at present, it states.

“There is a range of estimates on the current and future global electricity demand of ICT and associated carbon impacts. [These] estimates depend largely on modelling,” the report continues.

The variety of technologies and services measured to create these estimates varies widely, making it extremely difficult to get an accurate picture of what exactly is going on, it adds.

“It is estimated that ICT corresponds to around 3.6% of global electricity and around 1.4% of carbon emissions. Definitions vary, and if entertainment (film, music, games, etc), media (TV, radio, news, books, magazines, etc) and office printers are included, this increases to roughly 6% of global electricity and 2.4% of global carbon emissions,” the report points out.

Attempts to isolate and ascertain how much energy datacentres consume come with challenges

Attempts to isolate and ascertain how much of this energy consumption datacentres are responsible for come with their own set of challenges, claims Emma Fryer, associate director for climate change programmes at trade association TechUK.

A big part of this comes down to the different ways users classify and quantify the datacentres that make up their estates when calculating their own energy use. This, in turn, may result in them erroneously including small-scale, disparate server rooms in their running totals, for example.

“To my mind, a datacentre is where you consolidate remote IT functions. It is not a server on its own,” she said in a presentation at the recent Datacloud UK event in central London.

Users also sometimes fall into the trap of including in their calculations datacentres whose energy use may already be accounted for elsewhere, leading to a phenomenon Fryer terms “I am Spartacus syndrome”.

“If you ask someone how many datacentres they’ve got, they’ll say eight, when in reality they actually have two of their own, and the rest of the facilities are within other people’s wholesale [colocation] sites. A lot of it is duplication,” she says.

There is a tendency in the industry to repeat and re-quote estimates relating to the sector’s energy use without question, which – in turn – can lead to further “mythologising” about how much power datacentres use, she adds.

Are gas-powered datacentres the answer?

Against this backdrop of unknowns, it is perhaps not surprising that concerns about how the ongoing proliferation of hyperscale, colocation and edge datacentres will affect electricity supplies in the future continue to endure.

Indeed, predictions made in Cisco’s seventh annual Global Cloud Index report suggest the number of hyperscale datacentres in operation around the world will almost double from 338 to 628 by 2021, fuelled in no small part by growing enterprise appetites for public cloud services.

Elsewhere in the industry, market watchers are predicting that fleets of smaller, edge datacentres will be needed in years to come to support the rapid data processing needs of the millions and billions of internet-connected devices that are expected to come online, driving up energy usage even further.

In a letter to TechUK members, Fryer plays down the potential impact on supply this growth could have, and explains market forces already exist to protect against the datacentre sector’s energy use spiralling out of control.

“If datacentre energy growth really did get out of control, the market mechanisms would be deployed pretty swiftly by service providers because they would see an associated hike in costs that they would have to pass on to customers,” she writes.

“And, if they didn’t act fast enough there are plenty of evangelistic regulators who would only be too delighted to apply a price signal to digital activities.”

Investigating the alternatives

Even so, with one eye on safeguarding the capacity of the electricity grid, a number of hyperscale cloud giants are experimenting with using natural gas as an alternative source of datacentre power, and – as is the case in Ireland – a number of gas-powered builds are already underway.

The country – or more specifically, Dublin – has emerged as a popular destination for hyperscale datacentre operators, including Amazon, Facebook, Google and Microsoft, to site their European facilities in recent years, thanks in no small part to its temperate climate and congenial tax regime.

The amount of power these facilities draw from the electricity grid has not gone unnoticed, and has been cited as a concern by objectors to several high-profile datacentre planning applications in the country, prompting operators to consider natural gas as an alternative power source for their facilities.

“We’re looking at the [Irish datacentre] industry doubling in size over the next three years, in terms of megawatts [consumed] and square feet,” David McAuley, an advisory council member of Host In Ireland, an organisation that champions the country as a good place for overseas cloud firms to do business, tells Computer Weekly.

“We had rapid growth already, and up to now electricity has been available, but we’ve reached a point where datacentres are using up half the available grid capacity in Dublin – or, at least, will be.

“It’s kind of coming to a saturation point in Dublin, where a new infrastructure and electricity grid needs to be built, and electrical infrastructure at that scale, but these things take quite a few years to build.”

For Ireland, in particular, it is not much of a stretch to encourage more heavy power users to consider switching from electricity to natural gas, as the latter is already widely used around the country.

“About 40% of our electricity in Ireland comes from gas anyway, and the key thing is the infrastructure already exists to support organisations who want to tap into it,” adds McAuley.

So much so, natural gas has previously provided a stopgap energy source for datacentre operators that have, for whatever reason, been unable initially to secure a connection to the electricity grid in the country, he claims.

“The first one I looked at, two years ago, was a temporary gas connection that bridged a gap of about 18 months to two years while the electricity grid connection was being put together for the datacentre,” says McAuley.

“The client had an ultimate end-user client for the datacentre and needed to show they had power while they were waiting.”

Now builds are starting to emerge where gas is cited in the planning documents as the main source of power to the site. A recent example is a Dublin-based development, comprising of three two-storey datacentres, which secured the approval of Fingal County Council planning chiefs in January 2018.

The use of natural gas might prove tricky to square with the sustainability commitments many of the hyperscale cloud firms have previously made

“It is feasible in terms of infrastructure [for others to follow suit]. It costs maybe a few million to tap into that, and provide a pressure-reducing system to feed into the datacentre, and then they can generate their own power on-site,” he says.

The use of natural gas, however, might prove tricky to square with the sustainability commitments many of the hyperscale cloud firms have previously made, but one way to address that could be to make biomass energy available through the natural gas grid, offers McAuley.

“That might take a few years for the volumes [of biomass] to get to a point where datacentres could maybe do a power purchase agreement with a co-operative of farmers, for example, and maybe buy their gas directly from them. Those mechanisms are starting to evolve, with the government’s support,” he says.

Rationalising heat re-use

If there is further proliferation of gas-powered datacentres in Ireland, specifically, the sector’s heat re-use practices are likely to come under even closer scrutiny, as the amount of hot air they give out has emerged as another sticking point for objectors to protest against in the case of some builds.

“Datacentres are coming under the spotlight to do something with that heat, but it’s not really their game. They’re in the data business,” says McAuley.

The usefulness of datacentre waste heat is often downplayed, on account of the fact it is relatively low in temperature and requires huge investments in supporting infrastructure to transport it and process it to make it useful.

Gas-powered generators, however, give off a lot more heat and it tends to be much higher in temperature, which makes it a more attractive option for re-use. As a result, as plans for more gas-powered datacentres emerge, there is a risk the heat re-use issue could become an even bigger stick for objectors to use in protest against new builds.

It is, McAuley admits, becoming an increasingly common talking point for councils when deciding whether or not to grant planning permission for some builds.

“In terms of pressure on the grid, [natural gas] can help relieve it, but it opens up the waste heat question a lot wider,” he adds.

The exception to the rule

The Irish datacentre market is a bit of an anomaly, argues Ian Bitterlin, consulting engineering and visiting professor at Leeds University, and while gas-powered datacentres might work well for its hyperscale cloud community, it is unlikely to be a good fit for the majority of operators.

After all, it requires a lot of upfront investment in on-site generators, which have to run 24/7, and this will be difficult for datacentres containing less than 10MW to achieve.

“It is also not viable unless you use greater than 80% of the power output from day one, but most datacentres run at partial load forever,” he says.

“They [the hyperscalers] are all big and will load up their facilities [to side-step this], and can invest hugely upfront without shareholder justification.”

Next-generation natural gas

Microsoft has gone a step further, having debuted a 20-rack datacentre pilot build in September 2017 that combines natural gas with fuel cell technology to cut the amount of energy used to power its server farms in the first place.

“Right now, datacentres are powered by the electrical grid, which flows from a power plant, through multiple substations and transmission lines, and then must be converted into the right voltage for a datacentre before we can use it,” write Christian Belady and Sean James, the respective general manager and principal of Microsoft’s Cloud Infrastructure and Operations division, in a co-authored blog post about the project.

“With fuel cells powered directly from the natural gas line, we cut out all those steps and remove the energy losses that occur through this long transmission process.”

Fewer steps also means the number of potential points of failure in the energy supply chain to the datacentre is reduced, the pair claim, as is the cost involved in building the facility.

“Eliminating electrical distribution, power conditioning and backup infrastructure makes a datacentre easier and less expensive to build, operate and manage,” the blog reads.

The project also feeds into Microsoft’s decade-long push to make datacentres “disappear” by finding ways to significantly reduce the amount of resources required to operate them.  

“This innovation is aligned with our strategy to minimise resource impact, use our resources more efficiently and reduce embedded carbon and water in all our assets, while driving energy efficiency,” the blog concludes.

Whether natural gas becomes a viable alternative power source for datacentres, or an answer to any datacentre-induced energy supply shortfalls that befall the UK in years to come, remains to be seen.   

But McAuley is of the view that, as more gas-powered facilities come online, the famously risk-averse datacentre community will start to understand their appeal a lot more.

“Like everything, it comes down to trust. Does it work? Can I go to my board and tell them this is the solution? Because anything that is different to what has been done before is seen as risky,” he adds.

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