The planned decommissioning of the Mühleberg nuclear power plant from 2019 will result in the removal of a large part of the energy feed-in at the 220 kV grid level in Mühleberg. To ensure security of supply in the Greater Berne area, the missing energy must primarily be imported via Northwest Switzerland. To do so, Swissgrid is modernising and reinforcing the grid infrastructure. It is increasing the voltage of the transmission line between Mühleberg (BE) and Bassecourt (JU) from 220 to 380 kV and installing a transformer in the Mühleberg substation. The Bassecourt – Mühleberg extra-high voltage line, with a length of 45 kilometres, was already approved for an operating voltage of 380 kV by the Federal Inspectorate for Heavy Current Installations (ESTI) in 1978, but is currently only operated at a voltage of 220 kV.
Construction measures on pylons and the line
The future operation of the line at a voltage of 380 kV requires construction measures to ensure compliance with the applicable limit values for the electric field as well as the Ordinance on Electric Lines and Cables. The grid project's impact on the environment and the landscape are minimal. The noise emissions are below the target figures specified by law. This ensures that the most stringent statutory precautionary values pursuant to the Noise-Protection Ordinance (LSV) are observed.