Microsoft has drowned one of its data centers 100 ft below the surface of the North Sea. Why? To save energy. Oceans are uniformly cool below a certain depth, so keeping servers under the sea helps cut down the cooling costs that make up a large chunk of the operating budget of data centers. Plus, considering that half the world’s population lives within 120 miles of the ocean, placing data centers beneath the waves near the coast reduces the back-and-forth between users and servers.