Stockholm is heating residents’ homes with the excesses created by data centres. The Stockholm Data Parks partnership is incentivising businesses to move their data centres to the city with a cheap, carbon-positive solution to their need to cool the centres, which heat up as they’re used. Currently, data centres use about 3% of the global electricity supply and account for 2% of global warming, giving them the same carbon footprint as the airline industry.
Results & Impact
More than 30 companies have connected their data centres to the city's district heating network, including Interxion, Bahnhof, Ericsson and H&M. Stockholm aims to get 10% of its heat from data centres as part of its goal to be fossil fuel-free by 2040
The City of Stockholm, Fortum Värme, Ellevio, Stokab
Stockholm is well suited to heat recovery because it runs on district heating, which pipes hot water directly to people's homes rather them all heat water individually. The data centres will be run on renewable energy, and their excess heat sold to district heating company Fortum Värme or exchanged for free cooling as a service. Stockholm Data Parks will provide companies with cooling, power and dark fibre infrastructure
Entrepreneurs, city dwellers
Cost & Value
Running since 2017
The biggest challenge was finding the right space for Stockholm Data Parks. The partners needed to find land that both accommodates the needs of clients and has the capacity to host great deal of heat and power infrastructure. Stockholm Data Parks eventually found land in the city centre that suits its current needs, but partners expect expansion to pose a challenge: “Combining all the necessary conditions in the same place is something that will continue to be difficult, as we don’t really know what different data centres will want when they move here,” said Erik Rylander
Stockholm will use excess heat from data centres to warm homes across the city, as part of the city’s push to run independent of fossil fuels by 2040.
The amount of energy used by the world’s data centres – repositories that store and distribute large amounts of data – will triple in the next decade. Currently, data centres use about 3% of the global electricity supply and account for 2% of global warming, giving them the same carbon footprint as the airline industry.
Stockholm will funnel the excess heat generated by the centres into the city’s municipal heating system. The city has partnered with district heating company Fortum Värme, power grid operator Ellevio and dark fibre provider Stokab in the Stockholm Data Parks initiative. Its goal is for the city to get 10% of its heat from data centres.
The city already has 25 years of experience in recycling excess heat from steel and paper mills, as well as other manufacturing facilities.
“The system to capture heat from data centres is already here in Stockholm, which is a big advantage compared to most other places around the globe. Heat has a value in Stockholm: if you’re a data centre located in Nevada, heat has no value, but if you’re in a climate where the temperature outside is low, your excess heat suddenly has a value. We’re ready to pay for this heat because we already have the market,” said Erik Rylander of Fortum Värme, who serves as Head of Data Centre Cooling and Heat Recovery at Stockholm Data Parks.
“At the same time, data centres will contribute to making themselves and the city more sustainable. We have a tremendous challenge environmentally when the data industry is growing at such a rate,” said Rylander.
Stockholm Data Parks hopes to incentivise large data centres to move to the city with the promise of a cost-effective, carbon-positive data storage solution. The centres will run on low-cost, renewable energy, and excess heat will be sold to Fortum Värme or exchanged for free cooling as a service. Partners will provide power and dark fibre (fibre networks that are not currently in use, but in place to future-proof networks for exponential data growth) infrastructure in addition to cooling and heat recovery.
Excess heat is typically a liability for data centres: keeping servers cool takes a lot of electricity, which makes it both costly and bad for the environment. By offering to take on this problem for data centres, Stockholm Data Parks has created a new source of revenue for the city.
More than 30 companies have already connected their data centres to Fortum Värme’s network, including Interxion, Bahnhof, Ericsson and H&M. Stockholm estimates that there are more than 10,000 buildings across the city where the heat recovery method could be used.
A data centre with a 10-megawatt capacity will produce enough heat to warm 20,000 city apartments. Recovering that heat reduces emissions by 8,000 metric tons.
Stockholm runs on district heating: providers deliver heat via hot water to multiple buildings, rather than heating one building at a time. The system is conducive to reusing heat from data centres because it operates on a large scale, heating 90% of all buildings in the city, uniquely positioning it to reabsorb data centres’ significant quantities of energy. In the past, Stockholm’s district heating ran on fossil fuels. Now, providers aim to use waste heat or biomass.
A recent change to Sweden’s tax credit laws has made the electricity price for large data centres $0.04 per kilowatt – now the cheapest in the EU – which the city hopes will further incentivise businesses to move their data centres to the city.
The biggest challenge for Stockholm Data Parks was finding the right location to house sizeable data centres. Rylander and his colleagues needed to find land that accommodates the needs of clients, and has the capacity for a great deal of heat and power infrastructure. Stockholm Data Parks eventually found a space that suits its current needs, but Rylander expects expansion to pose a challenge: “Combining all the necessary conditions in the same place is something that will continue to be difficult, as we don’t really know what different data centres will want when they move here,” said Rylander.
(Picture credit: Flickr/Ian Insch)