From seabed to shore: Dieppe–Le Tréport offshore windfarm export cable installation reaches new milestone

Nexans has completed a key phase in the grid connection of the Dieppe–Le Tréport offshore wind farm for client RTE (Réseau de Transport d’Électricité). This milestone brings France one step closer to delivering a new large-scale renewable energy from offshore to shore.

About the project

Awarded in 2022, the contract covers the full turnkey delivery of export cables—offshore and onshore—for one of France’s largest offshore wind projects. Nexans is responsible for the design, engineering, manufacturing, installation, and protection of the 225 kV power cables, as well as long-term inspection, maintenance, and repair (IMR) services.

The wind farm, located in the English Channel, will generate up to 496 MW of renewable electricity—enough to supply approximately 850,000 people. It will play a key role in France’s broader goals for energy transition and independence.

A high-precision offshore operation

The recent installation campaign, completed this spring, involved more than 100 personnel and 15 different vessels throughout the various phases of the offshore operation. The work was led by Nexans’ cable-laying vessel CS Skagerrak and required tight coordination between offshore and onshore teams.

Key steps in the operation included:

• Preparation of the cable route and subsea nearshore trenches
• Floating of the export cable into position using temporary cable floats, guided towards shore by several powerful work boats maneuvering the cable in strong tidal currents
• Pulling the cable ashore through a pre-installed duct to the transition joint bay
• Removing the floats while ensuring position alignment with a pre-dug subsea trench
• Laying the cable into the pre-defined route, avoiding subsea obstacles such as large sand dunes and potential unexploded ordinances from WW2
• Backfilling of nearshore trenches and burial of the offshore cable into the seabed by means of jet trenching and mechanical trenching machines

Delivering value – technically and locally

The grid connection consists of two 23-km subsea cables and a 3-km long onshore section. Nexans also provides future value through its IMR services, ensuring the long-term reliability and performance of the infrastructure.

The last outstanding phase of the project, planned for August this year, is the final pull-in and connection of the export cables to the offshore substation, followed by the commissioning, completing the export cable link between the offshore wind farm and the French electric grid.

Enabling offshore wind at scale

As Europe accelerates its energy transition, large-scale offshore wind projects like Dieppe–Le Tréport are becoming essential building blocks. Nexans is proud to contribute to this transformation by delivering resilient, high-voltage cable systems that help electrify the future—safely, reliably, and sustainably.

Discover in video the key steps of the operation!

Note: texts are in French