Effective storage of energy at new Akershus University Hospital

Enriching project #17 144 of 31 000. Sweco has provided engineering design, planning and construction management services for Europe’s largest system for thermal energy recovery and storage at Akershus University Hospital outside Oslo.

Modern hospitals generate a large amount of surplus energy over time, particularly in ventilation systems and extra technology-intensive spaces. When there is also a large need for heating in other parts of a major hospital, a storage and recovery system is an effective solution to the energy problem.

With the help of a borehole thermal energy storage (BTES) system, Sweco has ensured that a full 57 per cent of the supplied energy for heating consists of recovered energy.

The BTES system is one of the largest of its kind in the world. To illustrate its size, an area covering two hectares of land has been used to contain the wells. All in all, around 150 kilometres of pipe have been laid to 228 wells that are filled with some 250,000 litres of antifreeze solution. Above the BTES, the field will continued to be used for cultivation of crops.

By using wells to store surplus heat from the chiller, it is also possible to spare the external environment from noise. Traditional chillers require bulky cooling towers on the roof of the building, with large fans to remove the warm exhaust air. Sweco has minimised the noise level and succeeded in avoiding the need for large and noisy root-top equipment.