In view of the federal government’s energy strategy, the capacity increase is necessary to transport the growing electricity production from hydropower in the canton of Valais to Central Switzerland and thus strengthen security of supply in Valais and the whole of Switzerland in the long term.
Expansion of important energy axes
To ensure Switzerland’s long-term security of supply, it is vital to implement the necessary increase to 380 kilovolts (kV) as quickly as possible. Expanding the grid in line with demand is a key aspect: distributing the energy flows over several north-south axes – e.g. via Grimsel or Gemmi – increases the transport capacity. The lines also play a role in the transfer of electricity on the north-south axis. Switzerland is not an island, but is integrated into the European transmission grid. This is important and, not least, also serves Switzerland itself, e.g. in the event of a shortage. Switzerland’s grid is only stable if the European grid is stable.
Energy production and the transmission grid in transition
The Mühleberg nuclear power plant was shut down in December 2019. As a result, there is a deficit in electricity generation in Central Switzerland amounting to almost 3,000 gigawatt hours per year. This corresponds to five percent of Switzerland’s energy production or the annual consumption of 700,000 households. In order to compensate for the electricity which is now no longer fed into the Swiss electricity grid, more electricity has to be produced in the medium term in other Swiss power plants, such as the 900 MW Nant de Drance pumped storage power plant, which is one of the most powerful in Europe, and transported to Central Switzerland.
Averting structural congestion
The Swiss transmission grid is already showing signs of structural congestion. The grid infrastructure in the canton of Valais is particularly affected. It is crucial to ensure the secure connection of the hydropower plants in the Alps with the consumer centres in Central Switzerland. Swissgrid already has to regularly instruct power plant operators to limit their production. That is why voltage increases to 380 kV are essential. This is the only way to transport the energy produced to other parts of the country, thereby ensuring security of supply throughout Switzerland.
Information on individual grid projects
Swissgrid is planning the construction of a new 380 kV line along a distance of 44 kilometres between the substations of Chippis and Mörel. The new 380 kV line runs away from the residential areas. The project is currently in the federal approval process.
The existing 220 kV line between Chippis and Mörel will be dismantled once the new line has been commissioned. This step will provide relief to residential areas, especially around Leuk-Susten, Niedergampel, Gampel, Steg, Raron and Baltschieder and Brig.
Ideally, the commissioning of the new 380 kV Chippis – Mörel line is planned for 2028. In the event of appeals and legal proceedings, commissioning may be delayed by several years.
Swissgrid has conducted a study on the underground laying of the lines for the Chippis – Mörel grid project. The objective is to take the local circumstances more closely into consideration and to better assess the technical solution and costs of underground lines. Swissgrid is currently preparing a study on behalf of the authorities to re-examine the line routing through the Pfynwald national protected area. Possible design options for an underground line between Agarn and Chippis are being examined in detail, e.g. mining the solid rock south of the Pfynwald to place the cabling behind the scree or bundling the project with the A9 motorway tunnel in the Pfynwald.
The Swiss Federal Office of Energy (SFOE) has suspended the approval process for around 6-9 months so that Swissgrid can carry out additional clarifications.
The extra-high-voltage line between Chippis and Stalden (Törbel line) will be strengthened to ensure the secure transport of energy from hydropower plants (including the Mattmark reservoir).
Today, the electricity pylons on the Chippis – Stalden line are only occupied on one side with a 220 kV power system. A second 220 kV system is now being installed on the power line.
On the section from Chippis to the crossing of the Emsbach in Agarn, the new line route will be defined in conjunction with the Chippis – Mörel grid project. The line route between Agarn and Stalden will remain unchanged.
The SFOE approved the expansion of the line between Agarn and Stalden in February 2022, giving the green light for the line conversion work.
The project comprises the voltage increase from 220 to 380 kV of the extra-high-voltage line between Chippis and Bickigen on the existing route.
The planned construction measures are necessary in order to comply with the currently valid ordinances and limit values. The heights of individual pylons will be raised and their foundations reinforced, insulators replaced or conductors tightened.
The Swiss Federal Office of Energy (SFOE) granted planning approval in February 2022. Appeals against the decision have now been lodged with the Federal Administrative Court. This is expected to delay the voltage increase of the Bickigen – Chippis line by another two years. Commissioning is planned by 2027.
The project involves constructing a new 380 kV extra-high-voltage line along a distance of 30 kilometres between Mörel-Filet and Ulrichen. The line will also carry a 132 kV railway power line for SBB and a 65 kV line for Valgrid.
On the section between Mörel-Filet and Ernen, the pylons will be installed and the foundation heads concreted in the next construction stage. The new pylons are already being erected with green paint so that they blend in better with the landscape.
The new 380 kV line is already in operation on the section between Ernen and Ulrichen. The old line has been dismantled, thereby noticeably reducing the visual impact on the localities of Ernen, Rekingen and Gluringen.
According to the current project planning status, the commissioning of the line section between Mörel-Filet and Ernen is scheduled for the end of 2023. The dismantling of the current 220 kV Swissgrid line and the 65 kV Valgrid lines will take place from 2024.
The 220 kV line will be rebuilt between the Electra Massa power plant in Bitsch and the switchgear in Mörel-Filet. The construction work for the pylon and cable installation is expected to be carried out in 2023.
The extra-high-voltage line between Innertkirchen (BE) and Ulrichen (VS) over a distance of around 27 kilometres is being replaced and, at the same time, the voltage is being increased from the current 220 kilovolts (kV) to 380 kV.
The Swiss Federal Office of Energy (SFOE) has set up a monitoring group to discuss the planning corridors proposed by Swissgrid and evaluate them in terms of their impact on space, the environment, technology and costs. The monitoring group’s recommendation then moves to the public collaboration stage. The plan is for the Federal Council to reach a decision on the planning corridor and the transmission technology between Innertkirchen and Ulrichen by the end of 2022.
The monitoring group’s recommendation to the SFOE consists of an underground cable between Innertkirchen and Oberwald and an overhead line between Oberwald and Ulrichen. There are two alternatives for the underground cabling between Innertkirchen and Oberwald which will cover a distance of around 23 kilometres.
- In Variant 1, the extra-high-voltage line will be routed from Innertkirchen to Handegg in a new cable tunnel that is yet to be built. Between Handegg and the Grimsel 2 power plant, the line will be laid in existing tunnels belonging to Kraftwerke Oberhasli AG (KWO). Between the Grimsel 2 power plant and Oberwald, the line will be again be routed in a new tunnel that is still to be built.
- In Variant 2, the extra-high-voltage line will be laid in the multifunctional Grimselbahn tunnel. The railway tunnel under discussion is to run from Innertkirchen to Oberwald. The extra-high-voltage line is planned in a cable tunnel running parallel to the railway tunnel.
With both alternatives, the line crosses the valley floor underground in Oberwald. A transition structure is planned on the south side of the valley. From there, the extra-high-voltage line runs over a length of 4.5 kilometres as an overhead line to Ulrichen as far as the existing line over the Nufenen Pass. Both options are equivalent from the point of view of transfer capacity.
Swissgrid and the Swiss Federal Office of Energy will be holding a public information event about the project in Oberwald (VS) on Thursday, 2 June 2022.
A modern substation will be built at the new location in Niederernen by the end of 2023. The old substation in Fiesch and the line connection will be dismantled. This will avoid the need to cross the valley and reduce the visual impact on the residential area.
The gas-insulated switchgear represents the core of the new 220 kV Ernen substation. In addition, a second 220/65 kV transformer will be installed to increase regional security of supply. Valgrid is building a new 65 kV substation at the Niederernen site.
Swissgrid has modernised the switchgear in Bitsch. Construction work began in April 2020 and the project was completed in April 2022.