Grid project Mörel – Ulrichen

Overview

The extra-high-voltage line between Mörel and Ulrichen will be newly constructed with a voltage of 380 kilovolt. Without connecting the transmission lines in the Valais to the 380-kilovolt grid, it will only be possible to transport around two thirds of the Valais production from hydropower once the new Nant de Drance pumped storage power plant commences operation. The construction of the SBB's new 132 kilovolt railway power line is also critical for the secure operation of the New Railway Link through the Alps (NRLA) at the Gotthard.

Improvement compared to the current situation

• The lines with lower voltage levels and the SBB railway power line will be bundled on the same pylons. This will relieve the burden on Goms.
• The new line will be built on the shaded southern slope further away from the settlement areas. The existing 220 kilovolt line will be dismantled. This currently passes through the centre of villages, especially in the region of Ernen, Ritzingen and Reckingen, impairing the development of these settlements.
• All provisions relating to limits for electromagnetic radiation are complied with, while the values in some areas are well below these limits. The noise burden is significantly reduced.

Project

Bitsch/Massaboden – Mörel section

The existing 220 kilovolt line between the Elektra Massa power plant in Bitsch and the switching substation in Mörel will be rebuilt. The pylons will be increased in height to accommodate the 132 kilovolt railway power line in order to maintain ground clearance according to the Ordinance on Electric Lines and Cables (LeV). Four completely new pylons will be built between the power plant and Termen.

The construction work for the pylon and cable installation will take place in 2019. In 2020, the pylons will be coated in green paint for protection against corrosion.

Mörel – Ernen section

In this section, the cable study for the «Binnegga-Binnachra-Hockmatta-Hofstatt» (Binna crossing) area requested by the Federal Court was submitted to the SFOE in October 2014. In its decision on 23 December 2016, the SFOE approved the overhead line version and dismissed all objections. Objections against the decision were submitted to the Federal Administrative Court.

Detailed specifications on the construction programme will follow as soon as the decision on the underground cable or overhead line version receives final approval.

Ernen – Ulrichen section

57 new pylons will be built and the existing 220 kilovolt and 65 kilovolt overhead lines will be dismantled between the Ernen and Ulrichen substations. The main work (foundation and pylon construction, rope installation) will take place between 2017 and 2020.

• The foundation will be constructed between April and November 2017. Four concrete bases will be erected at every pylon location and the foundations will be anchored in the subsoil with micropiles. The construction material will be transported into the impassable terrain primarily by helicopter, which will result in noise emissions at the construction sites.
• The installation of the pylons, which will be up to 85 metres high, will take place between April and mid 2019. The steel pylon sections will start to be delivered in the spring and will continue through to the summer of 2018 before the conductors are installed. The new 380-kilovolt extra-high-voltage line in the Ernen/Fiesch – Ulrichen section will already be able to commence operation in the second half of 2019.
• Between March and June 2019, the pylons will be coated in a green paint for protection against corrosion and to better integrate into the landscape. Swissgrid will then return the installation locations to their natural state and restore their ecological value. Swissgrid will also implement national nature conservation projects in the area of the new line route.
• In 2020, the existing 220-kilovolt line between Ernen and Ulrichen, which predominantly passes through villages, will be dismantled

Dismantling

The existing 220-kilovolt overhead line between Mörel and Ulrichen will be taken down after the new line has been commissioned. The existing 65-kilovolt Mörel – Ernen 1, Mörel – Ernen 2 and Ernen – Ulrichen overhead lines will also be dismantled.

Pylons, conductors, ground conductor and insulators

Steel lattice pylons and plastic insulators will be used for all pylons.

1,000-mm² Aldrey conductors are used for the transmission and railway power lines; twin conductors will be used in the transmission line. The 65-kilovolt line will be equipped with 600-mm² Aldrey single conductors. The ground conductor has a diameter of approx. 350 mm² and contains an integrated fibre-optic cable.

Substation Ernen

A modern 220-kilovolt substation will be built at the new location in Niederernen. The old substation in Fiesch and the line connection will be dismantled. This prevents the crossing of the Rhone and relieves the burden on the settlement area.

Cable study Binna crossing

A bridge solution to the Binna crossing is being considered for cable version 1. The cable bridge is a version in the topologically difficult area of the Binna crossing with steep drops on both sides.

The cable bridge could be used as a pedestrian connection. Special consideration must be given to the magnetic field on account of the proximity of the pedestrians to the cable arrangement. An aluminium panel could be attached above the cable arrangement to shield the magnetic fields.

Project Advisory Council

The Project Advisory Council is a consultative forum that allows the active involvement of the various members and in which mutual understanding can be promoted and different concerns can be raised directly.

The Project Advisory Council was constituted on 21 November 2013 to supervise the cable study for the «Binnegga-Binnachra-Hockmatta-Hofstatt» area and was used until the submission of the cable study to the SFOE in October 2014. The Project Advisory Council was composed of the following persons:

People & environment

Landscape

The new line routing is used in the entire project perimeter south of the existing building zones and residential areas. By moving the line from the banks of the Rhône and out of the open agricultural land to the wooded hillsides, the potential conflict of the existing 220 kV line from the construction zones in several communities will be resolved. In terms of the landscape, there will be a general improvement over the existing situation.

Due to the bundling with the 132 kV railway power line and the 65 kV line on the same pylons as well as to the higher voltage, however, the pylons will be taller than the existing 220 kV line.

Electromagnetic fields

A total of 19 buildings within the study perimeter were classified as OMEN. The magnetic field was calculated for all OMENs. In 18 OMENs, the system limit value of 1 microtesla was maintained. In one OMEN, the system limit was exceeded slightly – a dispensation has been granted for this.

Forests

The majority of the pylon sites are located in the forest. Other locations are used intensively for agriculture or include semi-dry meadows and extensively grazed areas.

To implement the line, a total area of 15,288 m² of forest need to be cleared for the pylon locations. The temporary clearing of 22,572 m² is required to provide access to the building sites and pylon locations. Suppression is necessary for an area of 292,471 m².

Fauna

• Amphibians / reptiles / small mammals / fish
  No special habitats such as ponds will be affected by the construction work. No interventions in fishing waters are to be made.
• Wild Game
  During construction, care will be taken to ensure that game is not disturbed, particularly during the hunting season. As almost all pylon locations are approached by helicopter, these helicopter operations will disturb the wild game only for a limited time.
• Birds
  No serious conflicts for grouse, golden eagles and migratory birds are to be expected. By moving the lines near Mörel, the potential for conflict for the peregrine falcon has been largely defused. The autumn migration is disturbed to only a small extent, as the line runs parallel to the direction of the valley along the slope.

Vegetation and habitats

The interventions are local and cover small areas; they will not lead to the disappearance of larger habitats.

• During the construction phase: The areas of intervention in the soil include the installation locations, the pylon locations and any temporary roads that are required
• During the operating phase: The interventions remain limited to the pylon locations

Replacement measures

The following overhead lines are to be dismantled with the commissioning of the new 380 kV line:

• existing Mörel - Ulrichen 220 kV overhead line of Swissgrid
• 65 kV Ernen – Mörel 1 overhead line of Valgrid SA
• 65 kV Ernen – Mörel 2 overhead line of Valgrid SA
• 65 kV Ernen – Ulrichen overhead line of Valgrid SA
• 65 kV Heiligkreuz – Fiesch overhead line of Gommerkraftwerke AG between Binnegga and Fiesch

The three 65 kV Fiesch – Ernen – Heiligkreuz, Mörel – Ernen and Ernen – Ulrichen overhead lines will be installed underground between the Fiesch power plant, the Ernen power plant and pylon No. 1461.

As the forest cover of the reforestation area will occur naturally, alternative measures were defined in addition to a real substitute:

• Tunetsch cultivated landscape: creating a new wet biotope
• Hockmatte-Schärtegga and Binnachra-Sengg cultivated landscapes: extension of the ecological network, keeping open the in-growth areas
• keeping various dry meadows and pastures open