The residents of Helsinki are suffering through their worst winter in nearly 30 years but help is at hand… or rather it’s inside a former bomb shelter carved from the bedrock beneath the Uspenski Cathedral. It’s here that, as part of the world’s most high-tech municipal heating system, surplus heat from hundreds of computer servers in a new data centre will be captured and pumped to heat hundreds of homes and businesses across the Finnish capital.

Helsinki residents are about to get warmer thanks to a data centre in a former bomb shelter. Nice.

According to an interesting report in the Times, Juha Sipila, the project manager for Helsingin Energia, the company behind the scheme said, “This will be the greenest and most energy-efficient data centre in the world”.

The report tells how the data centre will be cooled using seawater from the Baltic, which falls below 8C from November to May, with the excess heat pumped back into the city’s heating system — a solution that Sipila hopes will help to crack a pressing problem for the world’s IT industry.

“Data centres consume vast amounts of energy — about 3 per cent of all the electricity generated in Britain, for example. About two-thirds of the total is used simply for cooling,” says The Times, “That figure is growing steadily with the brisk expansion of so-called cloud computing, whereby the internet is evolving into a central store for data and processing for millions of businesses around the world. Global emissions of carbon dioxide from data centres are now equivalent to about a third of the total from aviation and are rising by 10 per cent per year.”

“For technology companies like Google and IBM, this is a very big issue,” Matti Roto, of Academica, a Finnish IT firm involved in the project, said. “The cost of paying for all that energy is huge — quite apart from the emissions — so it is very important to find solutions to improve efficiency.” Only about 40 per cent of the energy consumed by a typical data centre is used for computing, Roto said, with the rest needed simply to cool down the computers.

This centre’s power usage effectiveness — the central measurement of data centre efficiency — will be an unprecedented figure of less than one. The lowest figure for other centres has been 1.5. A similar project is under way in Iceland, which will use geothermal energy to power servers and cold seawater for cooling. Google has also announced plans recently to site a giant server centre in Finland.