Photo: Aethra vessel; Photo source: Asso.subsea

First inter-array pre-trenching campaign completed at Saint-Brieuc OWF

The pre-trenching campaign along the inter-array cable routes in the northern part of the French Saint-Brieuc offshore wind farm has been completed, Ailes Marines reported, adding that the work was done five weeks ahead of schedule.

The Aethra vessel, chartered by the inter-array cable supplier Prysmian, left the site on 14 August after completing all the work planned for the northern area as part of the first phase of construction activities and carrying out preparatory operations for the work scheduled to take place next year.

The vessel will return to the site in 2022 for the second phase of the offshore construction work.

Ailes Marines, a subsidiary of Spanish Iberdrola, announced in December 2020 that it would bury all the inter-array cables to allow for fishing activities within the project site, following discussions with the CDPMEM22 (the Departmental Committee for Maritime Fisheries and Marine Farming), the Maritime Prefecture, and the Prefecture of Côtes-d’Armor.

The new inter-array cabling plan, which guarantees maritime safety for future sea users in the wind farm area, was approved on 24 March and the trenching work began in June.

Shortly after starting the work at the Saint-Brieuc site, the trenching support vessel Aethra was forced to leave due to protests from the local fishermen in the project area. The vessel returned to the site as soon as the situation was under control.

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The ongoing activities – including the drilling and pile installation operations being done by the Aeolus vessel – are currently concentrated in the offshore wind farm’s northern part so that fishing activities can continue in the southern part.

At the beginning of this month, the developer requested from the CDPMEM22 and the Maritime Prefecture to continue with the drilling activities at three new positions located in the northern part of the project site.

After the request was transcribed into a prefectural decree regulating the uses of the area by the Maritime Prefecture, the Aeolus vessel positioned itself on the new locations to carry out the work.

The 496 MW offshore wind farm, located in the Bay of Saint-Brieuc in Brittany, 16.3 kilometres from the Breton coast, will comprise 62 Brieuc’s Siemens Gamesa 8 MW turbines.

Once operational in 2023, the wind farm will produce 1,820 GWh of electricity per year.