The world's greenest data center lies 30 meters below the ground surface of a cathedral in Helsinki, Finland. It's just part of an entire subterranean world being created for Helsinki's underground master plan.
CNN reports that Helsinki is the first city to develop such a plan, focused on building in its hard bedrock below ground. The city currently has hundreds of underground facilities and is planning to build more in order to avoid urban sprawl, free up the land, and maintain a nice cityscape.
The underground green data center cuts down on energy consumption by cooling their computers with sea water, and using the excess heat to warm Helsinki homes. Normally, nearly half of the energy used in data centers goes towards cooling down the computers. CNN reports that data centers consume at least 2% of all the world's energy.
While it seems that the data center may be green technology's poster child, Helsinki's underground coal storage facility is up for environmental debate. The four silos store enough coal to feed half of the city's annual consumption, and the company argues that it is environmentally friendly. But considering that the cleanliness of even "clean coal" is debatable, it's unclear just how environmentally friendly Helsinki's underground world really is.
WATCH this underground world: