Helsinki is about to get one of the greenest data centres in the world. One of the old wartime caves has been converted to a data centre. The heat from the servers is utilized to heat houses. In exchange for the heat, Helsingin energia will provide cooling in the cave.

Now why is this not done everywhere in the world? I don’t know for sure, but I would bet that the infrastructure is not in place everywhere. So what do the Finns have, that might be lacking elsewhere?

1. A lot of tunnels, solid bedrock and some old bomb shelters to use for the servers, that used to hide  VIPs from a neighbouring superpower’s massive bomb raids?
2. A city-wide central heating system? District heating is a completely normal form of heating in Finland, but Finland is the leading country in the world using this. Basically consisting off a network of hot water, running in a mesh of super-insulated pipes, dug under the streets. The buildings are connected to this network and the water in the sitting room radiators is heated in a central heating facility. This has won several awards for the Finns, Helsinki and Helsingin Energia.
3. A central cooling system to cool the data centre. The heat is exchanged for the cool air. The central cooling system is incredibly efficient and environmentally friendly. It gets the cold from various sources that would otherwise be wasted. One of the biggest is the sea. Seawater can be used as the main cooler for 6 months of the year (winter). During the summer, the heat from the (now idling) heat pumps and other sources can be used.

All in all, an incredibly simple and clever system. Most of the documentation is encrypted in Finnish, but there is some boasting available in English, here.