Underground
The length of underground lines operated at voltages of 63 kV and 90 kV increased in 2018, as 193 km of new lines were added. RTE notably brought into service:
- The 90 kV Le Laitier – Rom line in Deux-Sèvres (to address the distribution of load growth across different areas and the elimination of transmission constraints observed on the Poitiers-sud network),
- The 90 kV Herie-la-Vieville – Marle line in the Aisne (strengthening of the network to accommodate new renewable generation),
- The 63 kV Boutre – Cadarache line in the Var (to boost security of electricity supply to the CEA customer site in Cadarache),
- The 63 kV Scheer – Selestat line in the Bas-Rhin (part of the plan to strengthen the grid in the centre of Alsace),
- The 63 kV Athélia – le Castellet line in the Bouches-du-Rhône and Var (to enhance security of electricity supply to the coastal area between Marseille and Toulon),
- The 63 kV Breteuil – Hargicourt – Valescourt line in the Oise (restructuring of power supply to the central part of the Oise).
The undergrounding rate for new 63 kV and 90 kV lines was 93.2% in 2018 and has averaged 97.4% over the past three years (2016-2018).
Overhead
Conductors were replaced on 138 km of 63 kV and 90 kV overhead lines. Examples included:
- The 90 kV double-circuit Juine – St-Evroult line in the Essonne,
- The 90 kV Cerizay – Mauleon line in the Deux-Sèvres,
- The 90 kV la Farradière – le Thou line in Charente-Maritime,
- The 63 kV Betting – St-Avold line in the Moselle,
- The 63 kV la Chapelle-du-Châtelard – Cize – Servas line in the Ain,
- The 63 kV Bagatelle – Bram – Castelnaudary – Valgros line in the Aude.
Nearly 14 km of new lines were brought into service during the year, including 10 km on the Argentière – Briançon link in the Hautes-Alpes, as part of the plan to boost security of electricity supply to the Haute-Durance.