Microsoft Is Test-Driving a Submarine Data Center

Microsoft thinks it’s found a way to cut the high energy costs of cooling data centers: By putting them under water.

Company researchers tried out the concept by placing a prototype self-contained data center pod 30-feet under water off the coast of San Luis Obispo, Calif., and running it for 105 days, according to the New York Times.

The eight-foot-around metal unit was run and monitored from Microsoft’s Redmond, Wash. campus, where researchers got feedback on its performance and status from on-board sensors.

Microsoft is billing this effort, internally called Project Natick, as the worlds’ first submarine data center. But that’s not to say companies haven’t already gotten creative trying to cut data center air conditioning and power costs.

Nautilus Data Technologies, for example, is building a floating data center, which may be used by the U.S. Navy. And remember all those reports about Google data center barges floating off of Portland, Maine and San Francisco a few years back? Well, the stories were wrong, but the idea has legs.

The advantages of water are numerous. Submarine (or floating) data centers could use tidal-fueled turbines to generate power, for example. And, ocean water is cooler than ambient air, so A/C costs would be cut to the bone. Other companies are placing their new data centers in cooler climates. Facebook’s placed one of its latest state-of-the-art data centers in Luleå, Sweden to make use of cheap, renewable hydro power and outside air for cooling.

There are obvious risks for submarine data centers. Salt water is corrosive and weather can be a problem, to name two. But, per the Times report: “…the Microsoft researchers believe that by mass producing the capsules, they could shorten the deployment time of new data centers from the two years it now takes on land to just 90 days, offering a huge cost advantage.”

Google, Facebook, Microsoft and Amazon Web Services all run massive pools of computing power in data centers around the world to run their operations

Microsoft and Amazon, in particular, have been engaged in a land grab, adding new data center locations—in India, in the U.K, in South Korea—to broaden their respective geographical reach. Maybe that battle will move to the oceans as well.

This article originally appeared on Fortune.com