New underground cable line between Langacher and Sins now in operation

19.08.2026 – Axpo has commissioned a new underground cable line in Canton Zug. Measuring 5.5 kilometres, the section between Langacher (Cham) (ZG) and Sins (AG) has been in operation since this summer. The new high-voltage line replaces the existing overhead line, has a higher transmission capacity and enhances the landscape of Canton Zug as it is laid underground.

In brief:

• To ensure that electricity can continue to be transported safely and reliably to downstream energy suppliers, Axpo is switching the operating voltage in its supra-regional grid in Switzerland from 50 to 110 kilovolts.
• With the completion of the cabling project, Axpo has reached an important milestone: the new line between Langacher and Sins strengthens the security of energy supply and the performance of the grid infrastructure in Canton Zug.
• The underground laying of the new cable line and the dismantling of the overhead line are making an important contribution to conserving the local landscape in Canton Zug.

The high-voltage grid in Canton Zug ensures the supra-regional supply of energy to Zug’s people and businesses. To ensure a reliable and sustainable security of supply of energy, Axpo is increasing the operating voltage of its power lines in this region from 50 to 110 kilovolts (kV). As one of the final measures, Axpo has built a new 110 kV underground cable line over the past 15 months. It runs from the WWZ’s Langacher substation in Cham via Hünenberg to the Reuss. Tunnelling under the river was carried using a jetting method. On the other side of the river, the new line connects to the existing 110 kV line that leads to the Sins substation of AEW Energie AG. The new underground cable line will replace the existing 50 kV overhead line between Cham Bibersee and Sins, and will start operation at 50 kV for the time being.

Canton and municipalities cover additional costs

Since 2015, the Zug Cantonal Council and Parliament have, as part of the cantonal structure plan, advocated for requiring operators of high-voltage power lines to run the lines underground. With the underground laying of the line between the Langacher and Sins substations, a project of major importance for landscape conservation has now been completed. Once dismantled, the overhead line will no longer cut through sensitive natural landscapes of national importance and cantonal conservation areas. The same applies to townscapes of national importance. In addition, there are no lines running above the forest.

The fact that the overhead line is now laid underground is thanks to Canton Zug and the municipalities of Cham, Hünenberg and Steinhausen. Accordingly, the Zug Cantonal Council approved a loan for additional costs incurred as a result of the underground laying. The municipalities of Cham and Hünenberg also participated.

Now no longer required, the section of 50 kV overhead line from Cham Bibersee via Hagendorn to the cantonal border with Aargau near Sins – measuring 5.2 kilometres and with 32 pylons – will be dismantled in the coming weeks from mid-August to spring 2027. All materials will be disposed of properly or partly recycled.

On 19 August 2026, representatives of Canton Zug and the municipalities of Cham and Hünenberg as well as those involved in the project from WWZ and Axpo celebrated the commissioning of the new line.

Complete voltage conversion in Canton Zug

The power supply in Canton Zug is largely provided by Axpo’s supra-regional distribution grid. Axpo had already increased the voltage on some of its lines in Canton Zug from 50 to 110 kV in 2016. The complete voltage conversion in Canton Zug is scheduled for summer 2027. This requires the aforementioned new cable line between Cham and Sins as well as the conversion of the overhead line between the Altgass (Baar) and Langacher (Cham) substations. Both projects have now been completed.

Voltage conversion at Axpo

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.