Royal Haskoning: Residual data center heat in Stockholm en Finland

These days, almost all electricity that goes into a data center converts into “waste” heat and is then released in the vicinity of the data center. This waste product from the data centers could be a valuable source of heat. Only its low temperature limits the application. Luckily, by upgrading the heat and by connecting the data centers with the proper users, we can turn the “waste heat” into a useful resource. Royal HaskoningDHV has designed two large data centers in the Nordics; for both projects the waste heat from the data centers is effectively reused for other purposes. 


Yandex data centre Finland

Yandex data center Finland is located at Mäntsälä, Finland. The data center benefits from the cold ambient conditions and makes use of the direct outside air for cooling. The data center is designed for 40 MW of IT loads, with phase one – 10 MW – currently in operation.

To reuse the energy consumed by the data center, heat exchangers are installed to absorb the warm air stream. As a result, the cold water that runs through the pipes of the heat exchanger is heated up to more than 30 °C. The water is then upgraded by a heat pump station which is located next to the data center. Finally, the hot water is transported to its final destination where the data center heat can be reused.

With this smart solution, it is a win-win-win situation for all parties: Yandex data center profits from selling the “recovered heat” and reduced CO2 foot print, district heating companies are able to ensure a stable and cost effective energy source and the residents enjoy the comfort of recycled energy.


Figure 1 Yandex datacentre Finland


Telia Helsinki Data Centre

Telia Helsinki data center is located at Pitäjänmäki in Helsinki, Finland. The design capacity of the data center is 24 MW. The design has received a CEEDA Gold design-stage certification and is on its way of a LEED certification.

The data center will use exclusively “green” electricity generated from renewable energy sources and the waste heat is captured and reused which makes it “double green”. The temperature of the data center cooling process is approximately 30 °C. From there, the temperature is increased to about 70 – 80 °C by a group of two stage heat pumps. The high caloric energy is then supplied to the district heating system.

When the maximum number of 5,000 racks is fully operational, the data center will be able to warm around 20,000 flats with 200,000 MWh of delivered thermal energy annually.


Figure 2 Telia datacentre Helsinki (Parviainen Arkkitehdit)


Synchronize data centers with the district heating system

Finland has mature circumstances which are suitable for connecting data centers to the district heating system:

  • Due to its cold climate, thermal energy demand is greater than electricity demand;
  • Major cities, like Helsinki, have a well developed district heating system, which covers 90% of the heat demand.

Based on the full understanding of our customers’ business needs, Royal HaskoningDHV always explores the pioneering engineering solutions to enhance the society together.


Would you like to know more or are you interested to work on green data center projects with Royal Haskoning? Find the author’s contact details below!

Martien Arts

I am Director Mission Critical Facilities and Business Development at Royal HaskoningDHV. Feel free to contact me via