The existing 220-kilovolt line between the substations in Bickigen (municipality of Wynigen, canton of Bern) and Mettlen (municipality of Eschenbach, canton of Lucerne) has reached the end of its service life. Swissgrid is replacing the line in order to ensure the continued existence of this important transport axis in the Swiss transmission grid and to guarantee a reliable supply of electricity in the regions of Berne and Lucerne in the long term.
The 220-kilovolt line between the substations in Bickigen (municipality of Wynigen, canton of Bern) and Mettlen (municipality of Eschenbach, canton of Lucerne), which is 53 kilometres long, is the oldest line in the Swiss transmission grid. It was built in 1928 as a 132-kV line and upgraded in 1951 for operation at 220 kilovolts. Now the line needs to be replaced. This was shown by a comprehensive survey, during which all 178 electricity pylons and their concrete foundations, insulators and conductors were analysed and documented.
Swissgrid will replace the 220-kV Bickigen – Mettlen line in two stages:
Swissgrid operates the Swiss extra-high-voltage grid over a length of 6,700 km. It ensures that electricity gets to where it is needed safely, efficiently and in an environmentally friendly manner at all times. A strong and modern grid is required to ensure that Switzerland will continue to have a reliable supply of electricity in the future. The line between Bickigen (canton of Bern) and Mettlen (canton of Lucerne) is the oldest line in the Swiss extra-high-voltage grid. It was built in 1928 and has reached the end of its service life. Swissgrid is therefore planning to replace the line – to guarantee a secure supply of electricity in Central Switzerland and beyond.
At the end of March 2025, Swissgrid submitted an application to the Swiss Federal Office of Energy to initiate the sectoral plan procedure. The Transmission Lines sectoral plan (SÜL) is the Swiss government’s superordinate planning and coordination tool for the construction and expansion of transmission lines. The SÜL procedure consists of two steps:
In the Bickigen – Mettlen project, there was insufficient scope for several planning areas. Swissgrid therefore developed a single proposal for the planning area in consultation with the participating cantons of Bern and Lucerne. The planning area takes into account technical, ecological and regional planning factors. The aim was to avoid sensitive areas but to include all the necessary connection points.
Within the planning area, Swissgrid worked out possible corridor variants for the route of the new line. These working corridors are geographical areas of a width of around 400 to 2,000 metres. They show where the line could run in the future. A support group led by the Swiss Federal Office of Energy (SFOE) will decide which option will be pursued and submitted to the Federal Council for approval as part of the official sectoral plan procedure. The municipalities and the local population can also comment on the project and voice their concerns. All the details of the sectoral plan procedure can be found here.
Swissgrid has divided the planning area for the new 220-kV line into three sections. Possible corridors have been developed for each section, which will now be examined and discussed with a support group as part of the sectoral plan procedure. The aim is to find the best possible route for the new line.
| Section 1: Bickigen – Willisau | Two overhead line corridors (above the ground) were suggested for the Bickigen – Willisau section. Their location differs with regard to the municipality of Huttwil – one runs north, the other south of it. |
| Section 2: Willisau – Hellbühl | In the Willisau – Hellbühl section, four partly overlapping corridor variants for an overhead line are under discussion. They run either north or south of the municipalities of Menznau, Ruswil and Neuenkirch. |
| Section 3: Hellbühl – Mettlen | Two variants were developed for the Hellbühl – Mettlen section: a purely overhead line and a combination of an overhead line and an underground cable (below the ground) over a length of around three kilometres. Their location differs in relation to Rothenburg and Neuenkirch – one runs north of the current line, the other closer to Rothenburg along the existing route. |
As part of the SÜL for the Bickigen – Mettlen project, the routing of the 380-kV Innertkirchen – Mettlen line on the section between Mettlen and Hellbühl (Littau) is also being reviewed. This is because the Innertkirchen – Mettlen and Bickigen – Mettlen lines to the west of Rothenburg run closer and closer together. From Rothenburg onwards, they are bundled on two parallel routes as far as Mettlen.
Laying new underground cables in the Swiss transmission grid only remains possible to a very limited extent. This is the result of the Swissgrid cable study, which shows that the physical properties of underground cables make stable grid operation and the rectification of disturbances much more difficult. An uncontrolled increase in the proportion of underground cables in the extra-high-voltage grid would have a negative impact on Switzerland’s security of supply. For future grid projects, the possibility of installing an underground cable should therefore be considered from an overall perspective.
The project will reduce the impact on residential areas – in the municipalities of Rothenburg and Neuenkirch in particular, there will be a significant improvement on the current situation. The plan is to install the new line as far away as possible from residential areas. The existing line will be completely dismantled once the new 220-kilovolt line has been commissioned.
Next, a support group appointed by the SFOE will discuss the corridors evaluated by Swissgrid and assess the effects in terms of regional planning, the environment, technology and costs. The support group’s recommendation will then be subject to the official consultation procedure with the authorities and the public. The Federal Council is expected to define the corridor, and therefore also choose the technology for the new line, by mid-2027. Swissgrid will then establish the specific construction project and submit the planning approval application to the competent authority, the Swiss Federal Inspectorate for Heavy Current Installations (ESTI). This will be followed by a public consultation on the construction project.
The following schedule is based on the current planning status and represents the best possible scenario, without taking into account potential legal proceedings.
| Start of sectoral plan procedure | March 2025 |
| Public consultation procedure | Spring 2026 |
| Federal Council decision on corridor and technology | Mid-2027 |
| Development of construction project | Mid-2027 to end of 2028 |
| Planning approval procedure | 2029 to 2030 |
| Construction of the new 220-kV line | 2031 to 2034 |
| Dismantling of the existing 220-kV line | 2035 |
Swissgrid is organising two public information events. Find out more about the project and put your questions directly to the project team:
Grid project Innertkirchen – Mettlen
