The planned Facebook Danish data centre will feed hot air into the district heating system of the nearby city of Odense.
When the data centre opens in 2020, Facebook’s waste heat will be boosted by a heat pump, and delivered as hot water into the heating system run by local firm Fjernvarme Fyn. Facebook says that the heat will supply up to 100,000MWh of energy per year which can warm up to 6,900 homes. Odense is the third largest city in Denmark, with 175,000 citizens.
The Facebook announcement was the culmination of three years of preparations, the Danish Foreign Ministry said.
Facebook’s servers are cooled by air circulation, creating a stream of hot air that must be disposed of.
To reduce the energy needed to cool them, Facebook runs its servers as hot as it can, but even a hot aisle (air outlet) temperature as high as 48°C is still low for heat reuse purposes.
The hot air created in Odense will be piped past water coils which recover as much heat as possible. The temperature of that water will be boosted further by a heat pump which Facebook is building - and which will itself be powered with renewable energy.
Facebook said in a statement: “At all of our data centres, we aim to make our operations as sustainable as possible, but our ability to recycle heat from our servers is unique to our Odense data centre. This was made possible due to our close collaboration with the local district heating company Fjernvarme Fyn and its existing district heating network.”
The Odense centre, which will be just Facebook's third outside of the US, is expected to be “one of the most advanced, energy-efficient data centres in the world” and powered completely by clean and renewable energy, according to Facebook's director of data, Niall McEntegart.
District heating is well established in the Scandinavian nations. In Sweden, Stockholm has a number of data centres which are connected to a district heating system operated by heating company, Fortum Warme. The company just recently helped establish Stockholm Data Parks, a campus at Kista in Stockholm, which promises lower energy costs as well as a smaller environmental footprint.
This week, new co-location provider Multigrid connected to Stockholm Data Parks, claiming it will be the first data centre in a major European capital to attain a net energy cost of €0.03/kWh of IT-load.
Other tenants planning to open in the park include liquid-cooled data centre Borderlight and a private data centre being built by retailer H&M.
Facebook’s investment in Denmark comes shortly after Apple announced that it would build one of the world’s largest data centres in Viborg. Apple has also committed to “fund and boost” an expansive biogas research project at Aarhus University.
Foreign Minister Anders Samuelsen said: “I am very happy that Denmark has managed to attract yet another big foreign direct investment. Although only 1% of all companies in Denmark are foreign, they are responsible for 20% of all Danish jobs. For this reason, the Danish government works continuously to attract more foreign investments to Denmark."