The Gotthard line Airolo - Mettlen was built in 1933 (150 kV), the voltage was increased to 220 kilovolts at the end of the 1950s. Part of the line has reached the end of its service life and needs to be renovated due to its age. For the first time, an extra-high voltage line will be bundled with a national road tunnel. At the time of its planned commissioning, the approximately 18-kilometre-long Gotthard line will be the longest underground extra-high voltage line in Switzerland.
Swissgrid's extra-high voltage line Mettlen - Airolo runs over the Gotthard and is important for transporting electricity in Switzerland from north to south. Another task that the 220-kilovolt line takes on is the removal of energy from the regional hydroelectric power plants, so the transmission network is an important element in achieving the goals of the federal government's Energy Strategy 2050.
Extra high voltage in the road tunnel – a trailblazing project
FEDRO is planning to build a new service duct under the carriageway of the new tunnel. Swissgrid plans to lay the extra-high-voltage line between Airolo and Göschenen in this service duct. The plan is a trailblazing project – combining an extra-high-voltage line with a road tunnel is a first in Europe. The laying of such a long cable is a technical challenge which will allow Swissgrid to gain valuable experience. Various federal authorities have investigated the technical feasibility and the various safety aspects of the plans. Swissgrid will comply with all safety regulations and emission limit values at the Gotthard.