Équilibre Pylon design

An innovative pylon design concept developed for the replacement of an existing line - upgrading it into a two circuits 400 kV overhead line. In addition to the new design approach, RTE also chose to involve citizens directly in the process.

Objectives:

• Develop an aesthetic design for pylons
• Work on the successful integration of pylons into the landscape
• Improve several technical aspects of the pylon structure
• Create public acceptance regarding the overhead line replacement project

 

Main information:

Willing to improve the integration of an upgraded overhead line into the surrounding landscape, and thereby to increase its social acceptance, RTE decided to directly involve the 1.7 million people affected by the line by allowing them to choose a concept of power line that would meet local constraints. This initiative enabled local stakeholders to get involved in the grid development of their region. RTE published a tender for the new overhead line concept, for which 80 designers and architects sent proposals. RTE’s technical experts chose three projects from the 80 proposals received, based on the identified local needs and constraints. After being discussed in expert commissions, where citizens could give input, the Équilibre pylon designed by Hugh Dutton emerged as the winner.

The shape of the Équilibre pylon is a reference to a balanced arrow pointing towards the sky. The pylon’s name “Équilibre” is the French word for “Balance”, suggesting good integration into nature and stability.

Équilibre is composed of a 70m high white steel pole. The mast, which is made of rolled steel plate, is rather comparable to wind turbines than to usual lattice towers.

The 30 km long 400 kV line, 16km of which will be equipped with the new pylon, began construction in November 2019 and should enter into service in Autumn of 2021. Costs are estimated to amount to 1.88 M€/km, i.e. 56.4 M€ for the complete project.

Additional information:

• The triangle configuration of Équilibre’s cables helps to reduce the distance between the phases of each circuit and diminish the strength of the magnetic field created by the structure
• RTE is the French electricity transmission network operator. Its mission includes the operation, maintenance and development of the high and extra high voltage network. RTE also guarantees the smooth operation and security of the grid