Primeo Energy presents the new substation in Therwil to the public

Substation Therwil

On Saturday, 21 September, Primeo Energie will be presenting its new substation in Therwil to the public. During the open day, visitors will have the opportunity to view the substation and the nearby heating plant and learn more about the work of Primeo Energie.


Powerful, efficient, climate-friendly: in May this year, Primeo Energie put a new substation into operation at Ringstrasse 43 in Therwil. The facility replaces the previous substation, which was taken off the grid after more than 50 years of service. This Saturday, 21 September, the public is invited to visit the new substation during an open day. Primeo Energie is also offering tours of the nearby heating centre of the Oberwil-Therwil heating network. There will be an introduction to the grid electricians, as well as barbecue specialities and drinks.


Demand for electricity will increase
The new substation is currently equipped with two transformers. Each one has a capacity of 40 megawatts. In purely mathematical terms, that's enough to power 266 VW ID.3s under full load. The substation has space for a total of three transformers. With its current 80 megawatts, it is almost twice as powerful as the old substation, which is right next to it. The increase in capacity is necessary because the demand for electrical energy will increase with population growth on the one hand and the increase in electric cars and heat pumps on the other. The increasing supply of solar power also places higher demands on the power grid – and thus on the substations.


Operating life of more than 50 years
The new substation is designed for an operating life of at least 50 years. It supplies more than 19,300 customers in the communities of Bättwil, Biederthal, Biel-Benken, Binningen, Bottmingen, Burg, Hofstetten, Leymen (FR), Mariastein, Metzerlen, Oberwil and Rodersdorf with electricity.


Climate-friendly switchgear
An important aspect in the construction of the new substation was climate protection. The switchgears do not use SF6 gas or other F-gas combinations. SF6 has excellent insulating properties but is extremely harmful to the climate. A single kilogram of SF6 is equivalent to around 23 tonnes of CO2. Its use is therefore banned or severely restricted, with a few exceptions. At the substation in Therwil, Primeo Energie uses a 145 kV switchgear system from Siemens on the high-voltage side that is operated with nitrogen and oxygen. On the medium-voltage side, a 24 kV switchgear system from ABB is used that works with normal ambient air. A substation is used to increase or decrease the voltage with the help of transformers. In Therwil, the voltage is transformed from high to medium voltage and vice versa.