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Underwater data centres and why they are so cool (literally)?

Underwater data centres and why they are so cool (literally)?

Microsoft turned heads and made headlines earlier in 2018 when they literally sunk a whole datacentre under water. Is it a far-fetched idea or is it the future of datacentre computing and building?

Submarine for servers

Building a submarine for servers sounds expensive, and it is. However, the hope is that much of the total cost of ownership is upfront. Microsoft certainly thinks that the structure in place is simpler and more uniform that what they have for on-land data centres today. The expectation from Microsoft is that there will be a cost advantage by going under water.

Underwater data centre

Supply chain is existing

The 12 racks and 864 servers that make up the submerged Northern Isles data centre in Scotland came from a normal Microsoft Azure data centre on dry land. The main advantage of using this underwater data centre idea is that timeframes and economics are very different from those of building data centres on land. The whole underwater datacentre is a manufactured item just like the computers that are inside it, instead of a construction project, and the standard logistical supply chain can be used for these data centres to be shipped anywhere.

This also means spending less money in advance. It usually takes 18 months to 2 years to build new on-land datacentres. The underwater data centre, on the other hand, can potentially be built from standard stock and can be rapidly shipped within 90 days. Exponential growth of web services on the cloud can fuel huge demands for more data centres, and this idea will be perfect to satisfy this demand as long as the exponential growth exists.

Warranty savings

The underwater data centres can run autonomously without any supervision for five years. That is not very different from the current on-land data centre servers. The advantage of having these sealed underwater data centres is warranty savings. If a hard disk fails, nobody will go down there to replace; it’s a sealed enclosure. By the time the hard disk needs to be replaced, which would be in five years’ time, much better drive technology is available, so the whole data centre will be replaced with a newer-technology one instead.

Large scale

Eventually, large scale data centres will be possible, where multiple data centre modules will be sunk together interconnected to a central node. This, again, is not so different to what is currently being done on land. Such on-land data centres can span a mile between end to end server racks. In the future, the same philosophy could also be applied to sunken data centres to scale out multiple rows of racks together in the same fashion.

Green potential

Once underwater, power and cooling costs are very low. The technology to cool the data centres is the same as the one used to cool ships and submarines. Raw sea water is pulled in through the heat exchangers in the back of the rack and back out again. This cooling system can cope with very high power densities, such as that required by GPU-packed servers used for heavy-duty high-performance computing and AI workloads.

The Northern Isles data centre taps into the tidal generators of the European Energy Centre, located in Scotland. Tide is a reliable and predictable phenomenon that cycles through – and are known when they will occur. This tidal energy can be used to charge battery storage across the 24-hour cycle and the whole lunar cycle. They can also overprovision the tidal generation capacity to ensure reliability by running more tidal turbines than necessary. This system is completely renewable and has the smallest carbon footprint possible.


On-land data centres have increasingly relied more on water than on electricity as a source of power. As a result, they have a line into the city water supply, which might be acceptable in developed countries but not as much elsewhere. Underwater data centres, on the other hand, can be placed anywhere, including somewhere in the developing world without any constraints on the local water or power supply. There is absolutely no usage of the electric grid or water supply using these new underwater data centres.

Nitrogen atmosphere

The underwater data centre is designed to operate without physical interferences for up to five years. Apart from the cooling and power benefits, there are also benefits to operating costs that are almost zero, and much lower failure rates. Statistically, when humans fix things, other unrelated problems likely come about. By removing the human factor from these data centres, it is hoped that they will operate for the whole five-year life span that they are designed for.

Lower failure rates are expected because of the atmosphere that the servers live in. The atmosphere is cold and uses dry nitrogen gas at 12 degrees Celsius. With the nitrogen and lack of oxygen and removal of moisture, corrosion will also be minimal, so problems with connectors will be reduced. Even filling the interior with nitrogen is not very expensive since the air we breathe is already 70% nitrogen!


The concept of underwater data centres might look to be difficult and expensive at first glance. However, delving deeper into the equations involved, one can surmise that this will be a very inexpensive way to increase computing power reliably and cheaply for all data centre companies.


Vincent Farrugia is a network and systems manager at Deloitte Malta. For more information please visit