At the bottom of the ocean, just off the coast of Scotland’s Orkney Islands, to be specific.

As part of phase two of its initiative called Project Natick, Microsoft will leave the 40-foot-long Northern Isles data center 117 feet below the surface for 12 months. A team will monitor the facility’s humidity, performance, power consumption, sound and temperature during that time to determine if seafloor data centers could be a viable option in the future.

The goal of Project Natick is to find a sustainable way to keep very large data centers cool. The Northern Isles facility does this by pumping the cold seawater surrounding it through radiators attached to the backs of its 12 server racks. It gets the power to do this from the sustainable energy sources powering the Orkney Islands region, such as solar panels, wave energy converters, and wind and tidal turbines. A fiber-optic cable keeps it connected to the outside world.