Geothermal Energy Use in Switzerland

To give an overview of geothermal energy use in Switzerland, its principle of operation and the different available technologies are described. Geothermal energy refers to the use of energy taken from the underground. The use of geothermal technologies is sustainable and produces heat that can be used instead of oil or gas to heat a house and produce warm water. In Switzerland, the consumption of geothermal energy is small and only accounts for 1.0 % of the whole consumption of energy (BFS, 2010).

The technologies in the field of geothermal energy use are various. Their applicability is dependent on the specific underground as well as the local conditions such as available space, groundwater appearance, and the environmental standards in the particular region. Moreover, there are technologies that are used in a more widely way while others are new and still in research.

Although the downhole heat exchangers, energy baskets, and underground registers account together for 73.2 %, geothermal energy baskets take on only a minor role. They represent the technology with the smallest percentage rate and are thus to be said a niche product (Geothermie, 2011b). This might be due to the fact that this technology was only brought on the market 

How Geothermal Energy Baskets work

Geothermal energy baskets are made of spiral wound polyethylene tubes that are fastened with a metal skeleton (BFE, 2005a). There are two types available: conical and cylindrical energy baskets with different dimensions (see table 3 and 4).

The chosen dimensions of the baskets are dependent on the available space and the geological conditions of the soil. After having evaluated the size, the baskets are installed in 1-1.5m soil depth and are connected with each other. The depth is chosen to 1-1.5m because the baskets need to be installed below the frost line to prevent the baskets from freezing damage (BetaTherm, 2009b). The tubes are filled with a liquid made of water and anti-freezing agents. This liquid is used to absorb the warmth of the soil. The absorbed warmth of the liquid is then passed down to a heat pump which is used as water heating system in the household.