Located at an historic crossroads of power lines, this new substation will improve the quality of electricity supply and facilitate the energy transition in the department.

The network in the upper Allier valley was built in the 1930s. One of the first to have electricity in France, the area is at the crossroads between the Lozère, Ardèche, Haute-Loire and Cantal departments. The construction by RTE of the Montgros substation and its connection to the existing substation in Langogne will start a new chapter in this story. Thanks to RTE’s €30 million investment, the electricity network in the Lozère will be stronger thanks to the existence of two 225 kV substations.

RTE notably went out of its way to protect the local landscapes and environment. All new lines were built underground, so no new towers were added.

A total of 14 km of underground cables were also added between Montgros and Langogne.

To learn more, see the report on this project in RTE’s magazine, MAG RTE&Vous.

To sustainably increase security of supply to the northern part of the Montpellier metropolitan area, RTE built a new underground line between the Quatre Seigneurs and Saumade substations. Work began on this 7.8 km link late in November 2017 and was completed in 2019. This new underground line, a project undertaken by RTE for the benefit of the local community, gave the Montpellier metropolitan area a network connecting five substations capable of backing one another up starting in the winter of 2018. This will secure safe and quality electricity for a metropolitan area that will see a rise in power demand over the coming decades as it expands.

In 2018, RTE began work to bury three power lines in the eastern part of the Montpelier metropolitan area as part of a local undergrounding initiative (MESIL) project. By the end of 2020, RTE will remove 36 towers between the A709 motorway and Domaine de Verchant, passing through the Port-Marianne districts, eliminating a total of 13 km of overhead lines. This project is part of the plan to encourage economic development in the eastern part of the metropolitan area. Work is scheduled to be completed by the end of 2020, when the new underground lines will be commissioned.

The three lines in question are the 225 kV Saumade – Tamareau link, the 225 kV Montpellier – Pont Trinquat – Saint-Christol link and the 63 kV Castelnau – Fréjorgues – Montpellier – Pastourel link.

A new 63 kV overhead/underground power line between l’Argentière and Monêtier-les-Bains was brought into service as part of the plan to upgrade the electricity network in the Haute-Durance. The new line will strengthen the existing network, which was built in the 1930s and recently weakened by sticky snow.

This substation is supporting the region’s economic development, making it possible for a titanium investment casting foundry that supplies aerospace parts to move into Mazères and for an SNCF traction substation to be connected. It is facilitating the energy transition in Ariège by allowing the accommodation of renewable energies: two photovoltaic plant projects under review could feed local distribution networks alongside existing hydropower generation. It is also helping to improve quality of supply for the 5,000 residential and business customers in the region, a number that has been rising steadily due to the region’s demographic growth.

This underground line is improving security of supply to the Basque Country and is a first in terms of combining electricity and digital technologies.

With a budget of €10 million, the objectives of the project are twofold:

• Strengthen the link between Villefranque and Mouguerre, with additional support from the installation of two new transformers (400 kV and 225 kV) at the Argia substation (Villefranque);
• Install optical fibre directly inside the cables and sensors on the outside. With this technological first, RTE will be able to gather data in real time (temperature, vibrations, etc.) and thus optimise management of the cables while preventing and anticipating potential failures. The vibration sensors will also improve security around RTE infrastructure.