The “Northern Isles” subsea data center contains 864 servers and 27.6 million gigabytes of disk, tightly packed into a steel cylinder, and dunked into the North Sea’s icy, choppy waters. It was retrieved following a two-year-plus stint on the seafloor with only passing fish and marine organisms for company.
By
Alex Christian,
a British journalist who writes mainly about the effects of climate change in numerous international magazines. He is a permanent freelancer for Wired UK.
We publish his report here as part of our Publishing Partnership with Wired UK.
Analysis of the trial is still underway but, so far, the Northern Isles has been hailed a success. In 2014, researchers from Microsoft had the idea of sinking servers and data storage in the sea to optimize their cooling. The project “Natick” was born. In spring 2018, they placed an entire data center in the icy waters of the North Sea, packed in a steel cylinder and filled with dry nitrogen.
“The preliminary findings show that the underwater data center had only an eighth the failure rate that we see on land.”
More than two years later, the haul was reeled up from the ocean deep – coated in algae, barnacles and sea anemone. “Overall, we’ve found that underwater data centers are feasible, as well as logistically, environmentally and economically practical,” says Ben Cutler, Project Natick’s director.
Dumping a shipping container’s worth of electrical equipment into the ocean initially sounds like a circuitry nightmare. But there’s a reason why submerged servers may be eight times more reliable than land data centers, which are pinged by billions of people every day for any action done online: be it emailing, browsing or binge-watching. Placed on the seabed, cocooned from corrosive oxygen, moisture and bumps, data centers can seemingly thrive. “Computers don’t actually operate well in the same environment that humans inhabit,” explains Cutler.
From photos to messages and documents, we use cloud services every day – even more so in the working from home era. The cloud might seem nebulous and invisible. But every click and keystroke generates a piece of data that is backed up by physical servers which require round-the-clock power and cooling. Cloud expert Paul Johnston estimates:
Nearly two per cent of all the world’s carbon footprint comes from data centres.
It’s an industry which grows year-on-year: there are approximately 18 million servers deployed in data centres globally; worldwide spending on hardware and software topped more than £125 billion in 2019.
That’s why there’s more to the experiment than simply producing reliable hardware. Underwater data centres might actually be good for the planet. “Nearly 20 per cent of energy used by land data centres is keeping everything cool through air conditioning units and freshwater resources,” says Johnston, who is also a climate change and technology consultant. “What Microsoft has done is groundbreaking, with natural seawater acting as the coolant rather than air being artificially pumped. It could be an environmental win.”
Project Natick was born in 2014, exploring an idea of placing computers under water, powered by renewable ocean energy. The following year, a data center was dropped off the Californian coast for several months as a proof of concept. Scotland’s Orkney Islands was picked for the latest trial, due to its grid being wholly supplied by wind and solar energy. “Our findings show that perhaps we don’t need to have quite as much infrastructure to support power and reliability,” Cutler says. “Even in light winds there would likely be enough power.”
That’s in stark contrast to most land data centers, which are mainly powered by electricity generated by fossil fuels. And the Northern Isles experiment could be a sign of things to come. By placing underwater data centers close to turbines, energy providers would have a regular, local customer; those in charge of the data centers would receive efficient, reliable power. Johnston believes the demand could then further boost the UK’s thriving offshore wind industry. Smaller, underwater data centers could then lead to lightning-quick connections for remote coastal towns and villages, who currently rely on centralised data centers which can sometimes lie hundreds of miles away.
Cutler is confident that the underwater model can be scaled cost-effectively – it’s the potential next step for Project Natick. “The vessel is smaller than land-based data centers. To scale up, you could join several data centers on a single frame, like building blocks.” He adds that a submerged data center can go from factory to operation in less than 90 days – a much faster rate than land versions. But what happens when a data center 50 metres deep into the Atlantic needs repairing? According to Cutler, the model is self-sustainable: servers that fail early would simply be taken offline, while a lights-out data center would be retrieved once every five years. “It’s designed to have such high reliability that we can operate for several years without maintenance,” he adds.
Underwater data centers appear to be more reliable and energy efficient, but a coastline teeming with submerged data centers may not immediately seem like the best thing for sea life. However Andrew Want, a marine ecologist based in Orkney, doesn’t necessarily see a negative impact. “Any time you put anything into the sea you get a process called biofouling. A coating of microscopic bacteria appears in a few days, then organisms attach themselves to that coating.”
“It can act as an artificial reef which fish then congregate around, which can promote biodiversity.”
There’s the potential for underwater data centers to become sanctuaries, similar to how offshore wind farms have led to some fishing bans. “Fish like to aggregate around solid structures around nooks and crannies,” Want says. “Being just off the seabed, a data center could provide shelter for juveniles and act as a nursery habitat.” And although data centers would emit some heat, it’s unlikely that it’d be enough to warm surrounding waters. “It’s a similar phenomena that you see in subsea power cables, there’s negligible warming.”
But we shouldn’t start ripping out our land servers and dumping new ones in the ocean just yet. “We don’t see underwater data centers as replacing those on land, but view it as an additional offering to serve customers,” Cutler says. He adds that the Project Natick team is currently analysing what led to the limited failures that did occur with the Northern Isles. They’re also recycling its servers and components, while restoring the seabed to its previous state. Although pinging a server at the bottom of the ocean as you scroll through Instagram isn’t imminent, it’s certainly on the horizon. “Our internet consumption and electricity use is an indirect emission which has an unseen cost,” Johnston says. “At least with data centers dropped on the seafloor, that’s a more direct, visible impact that can be discussed. It will open up conversations which could lead to a positive, long-term outlook.”
