Microsoft declares underwater data centre experiment a success

Microsoft began testing its first underwater data centre in 2015, with a 105-day deployment in the Pacific Ocean. In 2018, it deployed a pod of nearly 900 servers on the seafloor at the European Marine Energy Centre, near the Orkney Islands, Scotland. The data centre was tethered to land via a cable which provided a fibre connection and power from renewable sources.

Now, Microsoft has retrieved the data centre and announced in a blog post that underwater data centres could be logistically, economically and environmentally feasible.

The Project Natick team had hypothesised that a data centre hosted in a sealed container on the seafloor could be more reliable than traditional data centre. Data centres on land can suffer equipment damage due to oxygen and humidity corrosion (the underwater container had been filled with dry nitrogen); temperature fluctuations, and people performing maintenance “banging things around”.

Checking the pod after its retrieval from the seafloor, Microsoft said that while there were a small number of failed servers (eight) and cables, the submerged data centre was many times more reliable than those on land, confirming the company's hypothesis.

“Our failure rate in the water is one-eighth of what we see on land,” said Ben Cutler, who leads Project Natick. “I have an economic model that says if I lose so many servers per unit of time, I’m at least parity with land. We are considerably better than that.”

This greatly improved reliability could eliminate the need to use replacement parts, with the few servers which fail simply being taken offline without a significant impact on service.

Project Natick also demonstrated that data centres located underwater can be kept cool without using so many resources, such as freshwater and power: “The consistently cool subsurface seas allow for energy-efficient data centres design. For example, they can leverage heat-exchange plumbing such as that found on submarines.”

According to Cutler, the team will now consider scenarios in which underwater data centres would be suitable, such as co-locating an underwater data centre with an offshore wind farm where even in light winds there should be sufficient power for the data centre.

Although building an underwater data centre with similar capacity to a standard Microsoft Azure data centre would be extremely ambitious, requiring dozens of these containers, there remains the possibility of deploying many smaller and more mobile data centres. The growth of edge computing is driving a need for smaller data centres located closer to customers. With more than half of the world’s population living with 120 miles of a coastline, locating datacentres on the seafloor near coastal cities could potentially allow for reliable, fast and energy-efficient service.

“We are populating the globe with edge devices, large and small,” said William Chappell, VP of mission systems for Azure. “To learn how to make data centres reliable enough not to need human touch is a dream of ours.”