Microsoft has placed a data center in the Scottish sea to determine whether it can save energy by cooling it in the sea. Data centers typically generate a lot of heat, and big providers try to move them to cooler countries to save on energy bills. Microsoft has been experimenting with subsea data centers for around five years, and previously sunk a data center on the Californian coast for five months back in 2015.

Today’s underwater data center will be deployed for five years, and includes 12 racks with 864 servers and 27.6 petabytes of storage. That’s enough storage for around 5 million movies, and the data center is as powerful as thousands of high-end desktop PCs. The data center will be powered by an undersea cable and renewable energy from the Orkney Islands. The cable will also connect the servers back to the internet.

Microsoft hopes the research project, dubbed Natick, will surface design and operational issues to inform whether it can make this a reality for more data centers around the world.