The world’s largest thermal energy storage installation is in an underground aquifer at the Arlanda Airport in Sweden.

Sweco was responsible for project development, engineering design and rconstruction of the Aquifer Thermal Energy Storage (ATES) and all connecting systems.

The ATES system consists of two groups of wells, forming a ”warm” group in the southern part of the aquifer, and a “cold” group in the northern part. The wells are connected to a pipe system ending at the distribution center where heat and cold from the ATES system is transferred over to a distribution pipe through a large plate heat exchanger.

The system consists of 11 wells, 5 cold and 6 warm. The water flow rate is 720 m3/h and the thermal capacity is roughly 10 MW. Calculated energy savings is 4 GWh/year electricity and 10 GWh/year district heating.

Thermal Storage