Electricity has been flowing along the upgraded extra-high-voltage line between Pradella and La Punt since 11 November 2022. This will eliminate a congestion point in the Swiss transmission grid. The Pradella – La Punt line is important for the security of supply in the canton of the Grisons and in Switzerland as a whole. As an alternative measure for the project, 1,100 distribution system pylons have been dismantled in the Engadin.
Swissgrid extended the extra-high-voltage line between Pradella and La Punt, which spans some 50 kilometres, in 2021 and 2022. More than 90 of the 127 pylons were replaced in the process. The electricity pylons on the Pradella – La Punt line were previously only fitted with a 380-kilovolt electricity system on one side. They now each carry a 380-kilovolt system on both sides of the pylon. This will significantly increase transport capacity, which will strengthen the security of supply both for the canton of the Grisons and for Switzerland as a whole.
Hydropower and international electricity exchange to ensure the security of supply
In the canton of the Grisons, a lot of electricity is produced by hydropower. In order for electricity to flow to the country’s consumer centres, grid congestion must be eliminated by modernising the grid and increasing transfer capacity. The transport of energy produced by hydropower in the Engadin will be considerably improved by the expansion of the line between Pradella and La Punt. But the project is also important internationally. The line represents a central link for electricity exchange between Austria, Italy and Switzerland.
The transmission system is being expanded in line with demand as part of Swissgrid’s «Strategic Grid 2025». To fulfil its key role as a pillar of the Confederation’s Energy Strategy 2050, the grid must be reliable and powerful.
Availability of broadband internet and dismantling of 1,100 pylons thanks to the new extra-high-voltage line
As an alternative measure for this expansion project, Swissgrid helped Engadiner Kraftwerke (EKW) to replace the 60 kV overhead line between Pradella and Bever with a 110 kV underground cable. This has led to the removal of 1,100 pylons from the landscape. The project has also enabled the hook-up of local municipalities to broadband internet via a fibre-optic cable that was laid at the same time.
The pylons between Pradella and Zernez will go green in 2023
The project is not quite finished yet. Next year, the pylons between Pradella and Zernez erected during the second construction stage will be given their definitive green coating. The pylons between Zernez and La Punt installed during the first construction stage had already received their green protective coating in the summer. Now the pylons fit much better into the landscape and are less visible. The coating on the pylons also protects against corrosion.
The project in figures
For this large-scale project in the Engadin, 260,000 screws and 5,000 tonnes of steel were used for the pylons, which are between 50 and 80 metres high. There are more than 600 kilometres of conductors hanging from the pylons, and around 7,500 kilometres of glass fibres for communication have been integrated into the earth cable measuring 52 kilometres, which serves as lightning protection. The green coating on the pylons requires 30 tonnes of paint, which will be applied to an area covering 100,000 square metres.