How the network evolved in 2018
  • Length of lines
  • Substation connections

    Length of lines

    With 105,857 km of lines in service, the transmission network continues to guarantee security of supply in the territories and regions while facilitating and supporting the accommodation of renewable generation.

    Highlights of 2018 included the completion of the “2 Loires” project (restructuring of power supply between Le Puy-en-Velay and St-Etienne), the creation of a 225/63 kV substation in Saône (to secure the supply of electricity to the Besançon area), and the start of work on the terrestrial portion of “IFA2” (new interconnector between France and England).

    New underground lines (newly created or overhead lines newly undergrounded) totalled 223 km, while 588 km of overhead lines were taken down (permanently or to be replaced) during the year.

    All in all, the length of the network decreased by 104 km year-on-year in 2018.


    Length of lines in service (km) Overhead Underground Total
    At 31 December 2017 99,964 5,997 105,961
    New 546 249 795
    Newly added 125 204 329
    Replaced 421 26 447
    Overhead lines buried 0 19 19
    Scrapped -588 -18 -606
    Other (placed in reserve, length adjustments…) -267 -26 -293
    At 31 December 2018 99 655 6 202 105 857
    Change 2018/2017 -309 205 -104



    The total length of underground lines in service ended the year at 6,202 km, topping the 6,000 km mark for the first time.

    At the same time, the total length of overhead lines on the transmission network continued to decrease, falling to 99,655 km.

    Closer look

    Better understanding

    Substation connections

    A total of 24 new substations were connected to the public transmission network in 2018, including 16 very high voltage substations. A 225/63 kV substation was notably commissioned in Saône, in the Doubs, to help guarantee security of supply to Besançon. The 225/90 kV Hérie-la-Viéville substation was also commissioned in the Aisne to facilitate the accommodation of renewable generation.

    Closer look

    Better understanding