Microsoft tests underwater data centre for more efficient cooling

Today, data centres contain thousands of computer servers generating lots of heat. When the data centres get too hot, the servers crash. Thermal management is becoming an increasing important and expensive part of industrial and enterprise computing. Microsoft believe that putting the servers under cold ocean water could cool the data centres without air-conditioning. Being heavily reliant on passive cooling means the interfaces must allow excellent thermal conduction away from the heat sources to the environment.

This solution could also address the exponentially growing energy demands of computing, because Microsoft is considering harvesting electricity from the movement of the surrounding seawater. One aspect of the project that has the most obvious potential is including either a turbine or a tidal energy system to generate electricity. For years, the main cloud computing providers have been seeking sites around the world, where they can utilise green energy and take advantage of the surrounding environment.

The demand for centralised computing has been growing exponentially. Microsoft manages more than 100 data centres around the globe and is adding more rapidly. The company has spent more than $15bn on a global data centre network. In 2014, engineers in NeXT at Microsoft Research began thinking about a novel approach to accelerate the process of adding new computing power to cloud computing systems.

Microsoft produced a large, white, steel tube, 8ft in diameter, covered with heat exchangers, with its ends sealed by metal plates and large bolts. Inside is a single data centre computing rack that was bathed in pressurised nitrogen to efficiently remove heat from computing chips. This solution might lead to strands of giant steel tubes linked by fibre optic cables placed on the seafloor, or suspended beneath the surface to capture the ocean current with turbines that generate electricity.

The company recently completed a 105-day trial of the steel capsule 30ft underwater in the Pacific Ocean off the Central California coast. The trial proved more successful than expected, even running commercial data-processing projects from Microsoft’s Azure cloud computing service.

The undersea capsules are designed to be left in place without maintenance for as long as five years. That means the servers, including all the interface materials and adhesives, have to be hardy enough to last five years without needing repairs. That is longer than is currently expected of these materials and they will have to improve in order to operate for this long in the underwater capsule.

If these data centres do not need maintenance, it becomes possible to redesign their physical alignment. Servers are put in racks so they can be maintained by humans. Without maintenance, it may be possible to reorient them in a more efficient way.

By using these underwater capsules, it may be possible to shorten the deployment time of new data centres from two years to just 90 days, offering a huge cost advantage and much more flexibility.

The underwater server containers could also help make web services work faster. Much of the world’s population now lives in urban centres close to oceans. Data centres are usually built in rural locations where land is cheap. The ability to place computing power nearer to users lowers the latency experienced by users.

Such a radical idea could run into stumbling blocks, including environmental concerns and unforeseen technical issues. The researchers had worried about hardware failures and leaks. The underwater system was outfitted with 100 different sensors to measure pressure, humidity, motion and other conditions to better understand what it is like to operate in an underwater environment, where on-demand repairs are not possible.

The research group has started designing an underwater system that will be three times as large. It could be built to incorporate an ocean-based alternative-energy system. The Microsoft engineers said they expected a new trial to begin next year, possibly near Florida or in Northern Europe, where there are already extensive ocean energy projects underway.