Apple has solar panels in Chinese yak fields. And Google and Apple both claim to be 100 per cent carbon neutral. Last year, Microsoft sunk a data centre into the ocean, and last month, announced it was ahead of schedule to hit its target of 60 per cent renewable energy in its data centres and would get there by 2020, while settling on a new milestone of 70 per cent by 2023.
That’s great. But there’s a but. Microsoft also doubled its in-house carbon tax to $15/ton, signalling it would boost that to $40/ton with its membership of the Climate Leadership Council — a controversial group that wants to give legal immunity to fossil fuel companies.
That last point highlights how environmentally-friendly stories make for positive headlines, but risk obscuring the real achievements and challenges on building sustainable data centres. And failing to get it right could have real consequences.
Analysts estimate that some 50 billion devices will be connected by next year — and to support all this tech, more and more data centres are being built around the world, rapidly becoming the biggest energy consumers on the planet.
Research suggests about two to four per cent of carbon emissions are from computing, be it the internet or cloud computing or corporate data centres. The environmental impact could rise as technologies such as 5G, the internet of things and driverless cars mean more data is collected, analysed and stored. John Andresen, associate professor at Heriot Watt University, suggests that figure could rise above ten per cent in the next five years — though others predict it could be more.
Despite that, you could be forgiven for thinking the problem was solved, or heading that way. Microsoft's company-wide aim is to cut its carbon footprint by 75 per cent by 2030, driven by doubling its in-house carbon tax. That carbon tax was started back in 2012 and is now in line with California's carbon pricing — it's also the reason Microsoft joined the CLC, as that organisation argues carbon taxes are the best way to cut emissions, though it also wants to avoid companies being held legally responsible for climate change. "This is all on the path to 100 per cent renewable energy," says Lucas Joppa, Microsoft's chief environmental officer.
Last year, Amazon and Google both claimed to have already reached that goal, flipping entirely to renewable energy sources for their global operations, which includes data centres. But exactly what they mean by renewable energy is complicated. The energy comes from two sources: directly purchased and from the grid.
The former involves long-term contracts that let companies buy truly renewable energy directly.
A decade ago, Google bought all the electrical output from a wind farm in Iowa. Microsoft did the same last year, signing a purchase agreement with a wind farm in Ohio. Such projects spur investment in renewables, letting energy companies build wind farms knowing they have a long-term customer. "Such agreements give the supplier confidence of a market for energy over a period of time, and so make it easier for them to invest in new renewable energy projects," says Chris Preist, professor of sustainability and computer systems at the University of Bristol. "So, in regions where the political will is there, it will certainly result in the deployment of more renewable energy over time." Or, as Joppa puts it, such contracts "help green the grid".
However, some percentage of Google, Apple and Microsoft's energy mix still comes from the grid. "After efficiencies, after direct purchasing of renewables, what's left we cover with renewable energy credits in the open market," Joppa says. Those renewable energy credits (RECs) are certificates that show an energy company generated renewable power and supplied it to the grid. To make the claim that they're carbon neutral, companies such as Microsoft or Google may buy the certificates when they have to draw energy from the national grid, as you can't trace the provenance of an electron bouncing around the grid. It's akin to any of us buying from a green energy supplier, but still drawing power from the same grid as everyone else; we feel like do-gooders, but it's purely metaphorical — the same amount of coal is being burned.
Lars Schedin is the CEO of EcoDataCentre, and finds such green consumption certificates frustrating. "That doesn't minimise any carbon dioxide emissions," he says. "It only means that I, as a private person, get the [non-renewable] mix in my home. You haven't done any good at all. It's just fooling society that they are improving the situation when they are not."
Microsoft said most of its 60 per cent renewable-sourced energy was from direct purchase, rather than credits, but would not confirm the ratio. Google and Apple both acknowledged the use of RECs or equivalents in their sustainability reports. Apple noted in its report that as of January last year, 66 per cent of its renewable energy comes from projects it created — either those it owns, such as the solar panels on its headquarters, or long-term purchase projects — with the remaining third coming from local renewable energy projects. If that's not enough, then it turns to RECs, though it does require them to be in the same state as the data centre it supports.
Apple breaks down the energy mix of its US data centres in its sustainability report, and that shows where real progress is being made. Its Newark, California data centre pulls from the grid, but via that state's Direct Access system Apple can buy directly from suppliers. There, it claims its energy is "mostly wind", and takes that to mean there were no emissions. On the other hand, its Reno, Nevada data centre is 99 per cent powered by Apple's own solar panels, with less than one per cent from purchase agreements — there's no question where the power is coming from.
Google, meanwhile, buys or generates more carbon-free energy than it uses at any given moment in its data centres, to make up for times when it needs to turn to the grid for more power. In one example, a data centre in North Carolina was 55 per cent carbon-free in April, 82 per cent carbon-free in September, and 49 per cent carbon-free in December, largely owing to a seasonal decline in solar-power generation — it's darker in winter, after all.
Those gaps were made up with excesses of Google-contracted solar power; there's more than it needs in sunnier hours of the day, so that power is pumped onto the grid. That means Google's data centre is still run on some carbon-based energy from the grid during darker hours, but it tries to displace that with cleaner energy for others during the day. Google's aim is to be entirely carbon free, but at the time of the report in 2017, in regions where purchasing agreements were signed, the reality was closer to 65 per cent, with none of its data centres fully matched at all times with totally carbon-free sources.
In short, when a tech company says its data centre and other operations rely entirely on renewable energy, it's actually a complicated mix of clean energy generated from their own buildings, renewable power projects they've signed long contracts with, and credits or excess power to fill the gaps. Whether that latter category counts as truly renewable or not will impact whether you think those 100 per cent claims hold water.
Of course, there are other ways to cut carbon emissions in data centres beyond buying cleaner energy, in particular around efficiency. "Reduce and renewable should be our mantra," says Preist. Schedin points to three considerations: efficiencies, reusing heat, and, as above, the source of energy.
The tech industry is getting better with efficiency. As Joppa explains, the cleanest energy is the energy you don't use — handily, it's also the cheapest, hence the investment into everything from reprogrammable chips to data centres powered locally by fuel cells. Andresen says more than half of the energy chewed through by a data centre is for cooling. "All the electricity going into the boards is converted to heat," he says. "For every unit of energy you put for data, you need 1.2 units for cooling — that's normally by fans."
This is why Microsoft sunk a data centre off the coast of Orkney in Scotland — it's sealed in a shipping container, so don't fret about the servers drowning. "Because the sea is only four degrees, it's kind of self-cooling," says Andresen. This is why cold climates (such as Iceland or Sweden) are so popular for data centre companies. If your servers are too hot, just pump in some cold air from outside.
But that causes another problem. "All the heat they are generating, they're just throwing it out the window," Schedin says. "You can actually see changes in the microclimate around big data centres. If you're looking to have palm trees in the northern part of Sweden, then that's good, but if you want to maintain the current climate in northern Sweden, then you should force data centres to reuse the heat somehow."
Heat generated by data centres at Schedin's company heat local buildings in the winter, while in the summer the excess warmth is put to making wood pellets, which he describes as a combination of wood shavings, pressure and heat. "Pellets are nothing but 100 per cent energy," he says. "Once you produce them they're easy to store. In the wintertime, when it's really getting cold, you burn those pellets instead of using oil or gas." That further helps reduce carbon emissions in the wider community, but excess heat could be used to warm or power any local building, with Schedin suggesting colocating anything from a greenhouse to a brewery next to data centres.
That's similar to Andresen's own project, which uses non-conductive liquids to cool the servers. "There's nothing new in that, but we can use that fluid for something useful," he says, explaining that it can hold heat up to 60 degrees Celsius. "It's enough to heat up water for homes." The project is based in Malaysia, which needs cooling more than heat, but there the hot liquid is used to power a heat pump to generate power. Using that excess heat saves emissions created elsewhere — it's a real carbon credit — but such systems are rare, says Schedin.
Aside from improving efficiency and reusing heat produced by a data centre, the third consideration Schedin says is the source of power, as above. But even with solid progress in long-term purchase contracts and generating their own clean power, there's still an environmental debt that needs to be counted. Building a wind farm or solar panels requires power and leads to carbon emissions, after all. Schedin calculates that into his firm's energy efficiency score, but most others don't. "They say that now they're using wind power, it's carbon neutral from the very beginning — no, it's not, sorry guys," he says. "It has an environmental debt from the very beginning – they forget about this part of the calculation because it's not their debt, it's the construction company who has the debt."
None of this belittles the progress made by the tech industry switching its data centres to renewable sources and cutting power use through technological and cooling efficiency — that should all be applauded, Microsoft included. "The work they do is genuinely useful, making them one of the leaders in the corporate world," says Preist. "But we all need to up our game." Despite the headlines suggesting 100 per cent renewable sources and the innovations such as sunken servers, there remains an alarming amount of work still to be done.
This article was originally published by WIRED UK
