The Federal Inspectorate for Heavy Current Installations (ESTI) has granted the necessary building permits for the line between the Nant de Drance pumped storage power station and pylon 126. Construction of the new 380 kV overhead line has begun.
The proposed new 380 kV line to transport the electricity generated by the Nant de Drance pumped storage power station between the power station itself and Le Rosel (Martigny) is divided into three sections:
- 6.5 km of cable line between Nant de Drance and the coupling station in Châtelard: building permission was granted on 1 July 2015 and engineering work in the tunnel and the cavern are currently underway. In addition, the installation of a 380 kV substation in the cavern was approved by the ESTI and work will begin in early 2016. With regard to the 380/220 kV switching station in Châtelard, the ESTI has already granted building permission and work began in May 2015.
- 12.5 km of overhead line between the Châtelard coupling station and the La Bâtiaz power station. Building permission for a section of this line was granted on 1 July 2015 and works began in June. Permission for a short section (from pylon 127 to La Bâtiaz) has yet to be issued. The building permit for the La Bâtiaz power station is expected to be issued in autumn 2015.
- 2.4 km of line between La Bâtiaz and Le Rosel. This section is the subject of opposition in the municipality of Martigny and various alternatives have been researched. Proceedings are underway with the ESTI.
Construction of the new overhead line between Châtelard and the Bâtiaz has begun: following the clearing of the areas concerned, civil works and the installation of new pylons commenced in mid-June 2015. The new overhead line will consolidate three voltages (2x380 kV + 1x132 kV Swiss Federal Railways) on the same pylons from Châtelard to pylon 127, then two voltages (2x 380 kV) to La Bâtiaz. The 2x132 kV Swiss Federal Railways overhead line will be moved down into the Trient ravine between Le Trétien and Les Marécottes and then buried up to Vernayaz.
The overhead section between Châtelard and La Bâtiaz is scheduled for completion by mid-2017. The existing overhead line will be dismantled once the new 380 kV line has been commissioned.
The proposed new 380 kV line between Nant de Drance and Rosel is essential for transporting the electricity generated by the Nant de Drance pumped storage power station, which will be commissioned in mid-2017.