Stockholm Data Parks, a partnership between the city of Stockholm; Stockholm Exergi, an energy company; Ellevio, a power grid operator; and others, aim to produce 10% of the heat required to meet Stockholm’s warming needs by 2035.
Around 1% of the world’s electricity is consumed each year by data centers, which also produce a tremendous quantity of heat that is typically wasted. Thus, in an inventive attempt to repurpose what is typically regarded as an unnecessary byproduct of computer servers’ constant number-crunching, Cities in Sweden and Norway are working to recycle the heat given off by data centers.
The majority of data centers just vent all that heat outside. However, by directing it into the underground water systems that run beneath a city or town, this heat can also be regenerated. After warming up houses, workplaces, or other facilities, the hot water returns to the data center to be heated up once again, beginning the cycle all over again.
According to Erik Rylander, the head of Stockholm Data Parks, everyone benefits when data center heat is recycled. Stockholm Exergi purchases all the waste heat that is offered by local data centers during the eight coldest months of the year and distributes it across the enormous district heating system of the city. Furthermore, Rylander said that data centers “get paid for something that is normally just a cost for them, which is cooling,” and that heat is less expensive than alternative sources.
The municipality of Bjrnafjorden in Norway is building Lyseparken, a business district, with all the necessary infrastructure for substantial data center heat recycling already in place. In a typical data center, the hundreds or thousands of servers produce a lot of heat, which must be vented out to avoid dangerously high temperatures.
On a smaller scale, companies and other organizations have been experimenting with data center heat recycling. One of these is the Amazon headquarters in Seattle, which is heated using surplus heat from a nearby data center. Over a 25-year period, the program, according to Amazon, will save electricity use by around 80 million kilowatt hours. Additionally, an adjacent office building uses the waste heat from the data center at Syracuse University.
However, according to Jon Sivert Rykkel, Bjørnafjorden business manager, in towns and cities that aren’t already set up for it, it is difficult and expensive to develop the necessary infrastructure for data center heat recycling. In order to lay the infrastructure down more cheaply, Bjrnafjorden decided to establish Lyseparken in a previously rural, undeveloped location.
Moreover, Rykkel added that the development of Lyseparken has lasted seven years, and that the project’s completion might take up to three decades.