CNet news.com picked up a Reuters article on a Finland data center with waste heat recovery.

Underground data center to help heat Helsinki

In the chill of a massive cave beneath an orthodox Christian cathedral in Helsinki, Finland, a city power firm is preparing what it thinks will be the greenest data center on the planet.

Excess heat from hundreds of computer servers to be located in the bedrock beneath Uspenski Cathedral, one of Helsinki's most popular tourist sites, will be captured and channeled into the district heating network, a system of water-heated pipes used to warm homes in the Finnish capital.

"It is perfectly feasible that a quite considerable proportion of the heating in the capital city could be produced from thermal energy generated by computer halls," said Juha Sipila, project manager at Helsingin Energia.

Beneath Helsinki's Uspenski Cathedral a new data center is being built whose heat will help warm homes in the Finnish capital.

(Credit: Jrielaecher/Wikimedia Commons)

And there are other benefits for location.

The center's location in the bowels of the cathedral has an added bonus: security. It is taking over a former bomb shelter carved into the rock by the fire brigade in World War Two as a refuge for city officials from Russian air raids.