Grid Pradella – La Punt
«A valley that you will fall in love with» – that is how the Engadine tourism office describes the region surrounding the River Inn in the canton of Grisons. Anyone familiar with the alpine valley is sure to agree. Between the peaks you will find deep blue lakes, fragrant pine forests and romantic mountain villages with sweet-sounding names. And, right in the middle, between Pradella and La Punt, a Swissgrid extra-high-voltage line. How – ever, what sounds like an alien object in the Lower Engadine only impacts on the landscape when you take a closer look, as the line is well concealed, especially in the forested areas. If you take a second look, you will notice that the pylons between Zernez and La Punt only have conductors on one side. It looks unusual, but, as the line was built in the last century, it was enough to cover the demand for transport capacity at the time. This demand is greater today and will continue to be in the future. The expansion of the existing Pradella – La Punt line is part of Swissgrid’s Strategic Grid 2025. To ensure the security of supply in the canton of Grisons and the transportation of Engadine hydropower, Swissgrid is adding another «system» to the line. The pylons will then carry a 380-kilovolt line, each with three conductors, on both sides.
Many people ask why the line is not being installed underground if it is going to be renovated anyway. Swissgrid conducted a careful review of the underground option, which revealed that the landscape would only have benefited in some areas and the costs would have been disproportionately high. As an alternative measure for the expansion, a line with a lower voltage (110 kilovolts) was installed underground between Pradella and Bever and commissioned at the end of 2019. This marked the start of the dismantling of 1,100 pylons. This not only benefited the picturesque landscape, but also gave a number of municipalities access to broadband Internet, as a fibre-optic network was installed underground at the same time.
1,100 overhead line pylons to be removed
Grid stability and security of supply are the priority
What challenges does Swissgrid still face in constructing the Pradella – La Punt line?
As we are building on existing pylons or even replacing pylons, we need to take the line out of operation. This needs to be coordinated with the European transmission system operators well in advance, as grid stability and security of supply are the priority. We already know that we will need to pause the construction work in both stages in August, because any decommissioning during this period would risk the grid stability. This is not really a problem as we have plenty of other work to finish, which does not directly involve the line.
The project will improve the security of supply. By how much and why?
The line between La Punt and Zernez currently only consists of a single line, as the transport demand was much lower when it was constructed in the 1960s than it is today. A second 380-kilovolt line will now be added. This will let us transport much more electricity and ensure the security of supply to the canton of Grisons as well as the transportation of Engadine hydropower.
When is the line currently scheduled to be commissioned?
The extra-high-voltage line is set to be commissioned at the end of October 2022.