By laying them underground, the lines in the alpine region are better protected from the weather and natural hazards. In addition, the villages and protected areas on the Grimsel could be freed from above-ground lines, write the Federal Office of Energy and the grid company Swissgrid in a statement on Thursday. The region is part of the UNESCO World Natural Heritage Jungfrau, Aletsch, Bietschhorn.
Swissgrid has to renew the aging overhead line on the Grimsel. At the same time, capacity is to be expanded from the current 220 to 380 kilovolts. The expansion is being carried out with a view to the federal government’s energy strategy and the associated increase in electricity production from hydropower.
Two variants are being discussed for laying the new high-voltage line underground. In the case of the first, part of the line can be routed in existing shafts, but new construction is also required.
The second variant is a combined railway and electricity tunnel. The new Grimselbahn will connect the Bernese Oberland with Obergoms. The railway side promotes the Grimselbahn because it could be used to connect the narrow-gauge network north and south of the Alps and thus well-known tourist destinations such as Montreux, Interlaken, Lucerne, Andermatt and St. Moritz.
From the “electricity” point of view, both variants are equivalent, according to Swissgrid. Depending on the variant, the cable network operator expects costs of CHF 210 to 250 million.
In both variants, a short section of around four kilometers between Oberwald and Ulrichen in the canton of Valais will be built above ground. The remaining 23 kilometers disappear under the ground. It is the longest cable in Switzerland.
The two variants will go into public participation from mid-June. A definitive variant decision should be made at the end of the year.
There are still a few hurdles to be overcome before a combined traction current tunnel can be built. The federal parliament must have regulated the financing by 2027 at the latest. And then the necessary building permits are required by 2030 at the latest.
If this does not succeed, the first variant with existing and new shafts will come into play, writes Swissgrid. The company aims to commission the new high-voltage line in the mid-2030s.