Castellum's Trekanten Complex

Castellum's Trekanten Complex

Virtually eliminating CO2 emissions while increasing overall performance.

Energy Consumption Reduction
CO2 reductions
Capital Expenditure
Savings on operating expenses
Payback period

At this building complex in Danderyd, Sweden, Energy Machines' integrated energy system provides 1.2 MW energy and completely eliminates the need to purchase district heating and cooling, while reducing its total energy consumption by 85%. The property, called Trekanten 5, includes 33,000m2 with offices and restaurants.

The collaboration between Energy Machines and Kungsleden (now Castellum) began in 2017 when we implemented an integrated solution featuring a geothermal energy system based on heat pumps. The system is intelligently programmed using Energy Machines' cloud-based control software, ensuring predictable and highly efficient operations.

Since the installation, the total yearly energy consumption at Trekanten 5 has significantly dropped from 118 kWh to an impressive 20 kWh/m2. This substantial improvement translates to a remarkable reduction of 26 tons of CO2 emissions per year.

“We have become turnkey contractors and have the opportunity to convert the building to be supplied entirely with fossil-free geothermal energy. It feels great that we have gained the trust of a major player in the real estate industry, who firmly holds sustainability as a key value. With their strict requirements, we have developed something really good together, ” says Thomas Göransson, Energy Machines' business manager, Northern Sweden.

The heat pumps are connected through Borehole Thermal Energy Storage (BTES), extracting and absorbing heat and cold from 51 boreholes, each 350m deep, all year round. The system solely relies on electricity to power the pumps, eliminating the need for multiple energy sources. Instead of paying for cooling, heating, and electricity separately, the energy is obtained once, circulated, and reused within the system. As a result, the installation can achieve significant energy savings up to 3,300 MWh annually encompassing heating, cooling, and domestic hot water.

“This feels very good to us. As property owners we have a great environmental responsibility and it also goes hand-in-hand with financial benefits. We knew we had to find a new solution for cooling and that was one reason why we chose this system. The total energy consumption is greatly reduced. Since we buy green electricity, the environmental impact will be very low,” says Sven Stork, Regional Manager for Castellum (then Kungsleden), Stockholm.

Energy Machines’ technology is flexible and can be adapted to most properties. Today, hospitals, spa facilities, offices, hotels, department stores, and residential buildings are supplied with heating, cooling, and ventilation. The growing awareness of the real estate industry's environmental impact causes customer inquiries to increase constantly and significantly.

At the time of commissioning, Trekanten 5 was owned by Kungsleden AB. Kungsleden has since been acquired by Castellum AB.

Energy Central at Trekanten

Contact about this case

Thomas Göransson
Business Manager

Technologies used

Other Energy Machines