Mojo Maritime France works 24/7 at the Floatgen floating wind turbine, which is one of the few prototypes installed in the world today, to replace a defective connection box which was preventing an electrical connection to marine energy converters.

Overview

SEM-REV is the first European site for multi-technology offshore testing that is connected to the French grid. It has all the equipment, offshore and on land, to develop, test and improve energy recovery systems (mainly from wind and wave sources).

The site’s operator, Ecole Centrale de Nantes, installed the subsea connection hub, to which three demonstrators can connect simultaneously on the SEM-REV site two years ago. Since then, projects have queued up to access one of the few multi-technology test sites in the world.

Challenge

However, final validation checks on the connection revealed an insulation defect on one of the phases of the 25km-long underwater cable, which had to be repaired to ensure it wouldn’t jeopardize future projects and was ready to supply energy to the French electrical grid.

It has taken eighteen months of intensive research to pinpoint the exact location, achieved thanks to advanced technologies based on electrical echometry and acoustics, implemented by teams from ENEDIS and EDF Energy.

Solution

Ecole Centrale de Nantes called upon the expertise of Mojo Maritime France - now James Fisher Renouvelables, as teams worked around the clock at the Floatgen floating wind turbine, which is one of the few prototypes installed in the world today, to replace a defective connection box which was preventing an electrical connection to wind and wave energy converters.

A large offshore construction vessel, the Ariadne, was chartered for the successful operation that lasted five days. As a result, the 8MW electrical connection is now operational and will start supplying its first kWhs in the summer of 2018.