Ecological concept
At D4 a lot of thought has gone into ecological considerations. From the choice of materials to waste disposal to power and water supplies, great store has been set on the sustainable use of resources. As well as optimising energy efficiency, D4 gives preference to the use of renewable energy, and aims to cover 50% of future needs from renewable sources.

Use of geothermal energy
The largest diffusion storage system in Switzerland guarantees D4 an environmentally compatible energy supply. Geothermal diffusion storage is at the heart of the energy concept, enabling us to exploit geothermal energy. The system involves introducing probes into underground rocks to a depth of 160 metres. Water is then heated by the probes via a closed circulation system and used for heating and refrigeration purposes.

Solar panels supplement power supply
Alongside the diffusion storage system, the solar panel installation is an important part of the energy system.
With a total surface area of 660 m2, the panels not only provide hot water and heating but also regenerate the geothermal storage system during the summer months.