Boulonnage d'un pylone - lignard RTE
Boulonnage d'un pylone - lignard RTE

Maintaining and making adjustments to the grid

RTE manages and maintains the biggest transmission system in Europe. The durations of its power outages are among the shortest on the continent. This achievement is due to constant infrastructure maintenance. Efforts to upgrade the grid are even more impressive, ranging from digitised control and the integration of renewables through to the mitigation of its effects on the environment.

100,000 km
of overhead lines
5,000 km
of buried lines
electricity pylons

maintenance workers

 Maintaining, upgrading and rationalising the grid

Maintaining and making adjustments

Making maintenance a priority


Maintaining the transmission system is essential for ensuring that everyone has access to electricity around the clock and every single day of the week.

RTE rationalises the use of its existing infrastructure in order to improve grid performance, to prolong grid service life, to lower costs and to minimise its effects on the environment. While making sure that it is equipped to do so. For example with project OLLA (Overhead Lines Lifespan Assessment), RTE is able to estimate the level of damage of overhead power lines conductors, and thus determine when is the right time to replace them. As a result, RTE is able to ensure the reliability of its infrastructures at a lower cost.

More than 4 000 RTE workers (half of its workforce) are constantly being called upon to identify potential failures and repair any faults. Night and day, in stormy or freezing weather conditions and even on Christmas day, our 170 maintenance teams – spread across the entire country – respond incredibly quickly to restore power as swiftly as they can.

Proud of their role as providers of a public service, these women and men have built up a unique set of maintenance skills for working on live equipment: they repair equipment without de-energising it and without depriving anyone of electrical current. The storm for which the winter of 1999-2000 will be remembered involved them in a huge mechanical upgrade project that lasted for 15 years.

Read their story in "Legacy of the storm"

Maintenance is now becoming more high-tech and drones are being used to monitor infrastructure in inaccessible areas more effectively, for example.

  • Moving towards a more resilient and state-of-the-art grid


    Increasing use of renewables; unequal distribution of generation and consumption areas; average age of equipment (50 years): the transmission system is facing challenges from all sides, thereby requiring major changes.


    RTE is in the front line when it comes to fighting climate change. Increasingly violent storms, floods and heatwaves are threatening the grid, which has to become more resilient in order to maintain security of supply. In addition, RTE is actively involved in the integration of renewables whilst also doing its utmost to reduce its infrastructure’s footprint on biodiversity and the landscape.


    A new set of tools, largely digital, is being used to rationalise the way in which the grid is operated. More flexible systems such as virtual "RINGO” lines are being developed to provide round-the-clock access to high-quality and affordable electricity.

    A changing energy world

    La transition énergétique : comment assurer l’alimentation électrique de tous alors que certains moyens de production sont intermittents ? (éolien, photovoltaïque, etc.)

    Discover the flexibilities imagined for the network

    Datas about renewable in France
    Maintaining and adapting the grid

    Ten-year network development plan

    “An upgraded and revisited grid helping to successfully complete the energy transition”. Such is the title of the plan submitted by RTE in September 2019. While relying as far as possible on existing lines, this plan sets out the upgrades that the grid will require by 2035 in order for it to align with France’s multi-annual energy plan and with the changes being made to Europe’s energy mix.
    The plan rests on five cornerstones:
    - An extensive upgrade cycle.
    - Rationalised use of existing lines through the use of technology.
    - Stepping up grid digitisation to enhance system flexibility.
    - Doubling exchange capacities with neighbouring countries over a period of 15 years.
    - Developing an offshore grid to integrate wind power at a rate of 1GW/year.
    Regional renewable-energy grid integration plans (abbreviated to “S3REnR”) are rolling out renewable-energy integration capacities across the whole of France whilst stipulating the upgrades needed to accommodate them and to evenly distribute costs.

    Digital technology supporting the grid: SmartGrids

    SmartGrids rely on digital tools to rationalise the use of existing infrastructure, to combine economic logic with technical challenges, and to get the best out of Europe’s energy mix.

    RTE is investing in Research & Development to design new tools and software for enhancing the efficiency of the electricity market and for making the power system smarter. The company is also supporting a number of pilot projects that will help SmartGrids move from the trial phase to large-scale roll-out by working not only alongside all players in Europe’s power system but also alongside new partners from the digital world.


    Electricity transport: a stable cost

    Investments for the grid UE

    By comparing the amounts being considered for investment with the power output of each country, the amounts being committed to France’s ten-year network development plan (SDDR) lie firmly within the bottom end of the range: France is one of the countries that will need to invest the least.

    France, stable grid costs RTE