Start of construction of underground cabling from Langacher to Sins (Canton Zug)

26.03.25 – To ensure the future energy supply, Axpo is increasing the operating voltage of its power lines in the Canton Zug from 50 to 110 kilovolts (kV). This will increase transmission capacities and reduce transmission losses. As part of this project, the existing line between the Langacher and Sins substations will be laid in the ground. Construction work will start at the end of March 2025. 

The high-voltage grid in the Canton Zug ensures the transregional energy supply for the population and economy in the Canton Zug. To guarantee a reliable and sustainable energy supply, Axpo is increasing the operating voltage of its lines in this region from 50 to 110 kilovolts (kV). As one of the last measures for the voltage conversion, Axpo is constructing a new 110-kV underground cable between the Langacher and Sins substations in the municipalities of Cham, Hünenberg and Sins. The new underground cable will replace the existing 50-kV overhead line between Cham Bibersee and Sins. The canton and the affected Zug municipalities have advocated replacing the overhead line with an underground cable. This is in line with the requirements of the cantonal development plan. Accordingly, the Zug cantonal council approved a loan for additional costs incurred by laying the cable underground. 

Complete voltage conversion

The power supply in the Canton Zug is largely provided by Axpo's supra-regional distribution grid. Axpo was already able to partially convert the voltage in the Canton Zug in 2016. The complete conversion requires the new cable line between the Langacher and Sins substations, as well as the conversion of the overhead line between the Altgass (Baar) and Langacher substations.  

At the end of January 2025, the Eidgenössische Starkstrominspektorat (ESTI) approved the plans for both projects. Axpo plans to complete the full voltage conversion in the Canton Zug by 2027. The 50 kV overhead line section between Lake Bibersee in the municipality of Cham and the cantonal border at Sins, which is no longer needed, will be dismantled after the entire voltage conversion in the Canton Zug. By this, the landscape will be relieved.

Route

The new underground cable runs from the WWZ's Langacher substation via the Langacher area to Untermühle and Sinserstrasse in Lindencham. From there, it runs along Sinserstrasse to the Matten area in the municipality of Hünenberg and on to the Reuss. The Reuss will be crossed by means of a horizontal directional drilling and the line will be connected to the existing 110 kV cable line that leads to the Sins substation of AEW. Construction work on the new cable line will start at the end of March 2025.

The decision in favour of this route was made in close consultation with the Canton Zug, the relevant authorities and interest groups.  

Adjusted traffic routing

During the construction period, there may be occasional traffic delays. Axpo has worked closely with the relevant authorities to develop a traffic regime that will ensure the smoothest possible flow of traffic. Along the cycle path on Sinserstrasse between the Hagendorn bus stop, Grobenmoos and the Matten turn-off, Hünenberg, access to the cycle path will be guaranteed at all times. 

The crossing of Maschwanderstrasse (Hünenberg) will be carried out in an open trench. During the construction period, traffic will be guided past this construction site using a traffic light system and, if necessary, a traffic service in single-lane operation.

Voltage conversion 

Axpo is gradually converting its existing supra-regional distribution grid from 50 to 110 kV. This will enable more electricity to be transported and reduce grid losses by up to 75 per cent. In this sense, the voltage conversion makes an important contribution to ecological and economical grid operation. An efficient and effective power grid is essential to ensure a reliably high and sustainable security of supply for the whole of north-eastern Switzerland, now and in the future.