In Switzerland, an existing geothermal probe system was specifically expanded for the construction of a new apartment building. Two 200-meter-deep double U 40 mm geothermal probes were already present on the property, originally installed for the demolished single-family home.
During the concept phase, it became apparent that this existing system only barely met the requirements of SIA 384/6. The calculated average fluid temperature after 50 years was approximately -1.3 °C. While the system was fundamentally usable, it possessed only a small thermal reserve.
To increase operational reliability and simultaneously improve the efficiency of the heat pump, the geothermal system was supplemented with separatus energy piles. The aim was to gain additional thermal output without drilling another geothermal probe borehole.
What makes this project special is the use of building components that are already necessary. For the excavation of the multi-family building on a slope, bored piles were installed to ensure slope stability. These piles fulfill an important structural function during the construction phase. However, after completion of the construction work, they are often no longer needed permanently.
With separatus, these components gain long-term benefits. The bored piles were equipped with separatus probes and thus activated as energy piles. In this way, a temporary excavation support becomes a permanent component of the heat supply.
A total of 11 bored piles, each 9 meters long, were equipped with separatus probes. This resulted in almost 100 additional meters of drilling for the geothermal system, without requiring a single additional borehole.
The separatus energy piles complement the existing two 200-meter-deep geothermal probes. This reduces the thermal load on the existing probe field. At the same time, the operating conditions of the heat pump are improved, as higher brine temperatures can contribute to a better COP.
Thanks to the intelligent splitpipe connection technology, the individual bored piles are hydraulically connected in series. This guarantees turbulent flow, and at the same time, the distribution system only needs to be expanded by one circuit.
The addition of energy piles not only increases plant safety but also the efficiency of the overall system. This approach is particularly interesting for existing plants, projects with limited space, or replacement buildings.
This project impressively demonstrates how separatus is creating new possibilities for near-surface geothermal energy. Building components that are already being constructed for structural reasons can also be used for energy generation. This creates new heat sources without requiring additional land or drilling for ground probes.
Especially on slopes, in confined spaces, or with complex boundary conditions, this approach can be crucial. separatus increases the feasibility of geothermal projects, reduces additional costs, and creates long-term added value from existing components.
Construction is currently in full swing. The next step involves installing the probes and energy piles under the foundation slab and into the building before the slab is poured. The system is scheduled to be commissioned in early 2028. We look forward to updating this reference with further findings in due course.
The message is already clear: With separatus, excavation shoring becomes an energy source. This is how efficient construction with geothermal energy works.
