Offshore cable repairs to ensure an uninterrupted supply of electricity

TenneT has awarded a framework agreement to Jan De Nul Group for repairs of TenneT’s offshore high-voltage cables in the German Bight. TenneT’s mission is to ensure a reliable and uninterrupted supply of electricity in its high-voltage grid and therefore, Jan De Nul Group has been appointed by the leading European electricity transmission system operator to mobilize in the event of high-voltage cable system faults or failures within the contractual period.

The scope entails repairs of all TenneT’s existing HVAC cable systems connecting individual wind farms to the offshore convertor stations or directly to the onshore grid, as well as repairs of all TenneT’s HVDC cable systems connecting the offshore convertor stations to the onshore grid. In addition, any future connections commissioned within the duration of the agreement will be added to Jan De Nul’s scope. The contract covers a period of 24 months with two optional extensions of 12 months each.

Cable Laying Vessels Isaac Newton and Willem de Vlamingh

Jan De Nul Group has already initiated the preparatory engineering works required to perform the cable repairs. In the event of a HV cable system fault or failure, Jan De Nul will immediately mobilize one of its offshore cable laying vessels, either Isaac Newton or Willem de Vlamingh.

In 2018, the Willem de Vlamingh installed HV cables to connect the Trianel Windpark Borkum and Borkum Riffgrund II wind farms to TenneT’s DolWin Gamma and Alpha offshore convertor stations. These cables are also subject of this framework agreement.

Worldwide track record

Jan De Nul Group has executed several cable installation projects in Belgium, the United Kingdom, Germany, Iceland, Egypt, Canada, Mexico, Russia, Taiwan and in the Middle East. In addition, Jan De Nul has installed multiple cable joints over the past years, including the cable joints for an urgent cable repair in 2017 in Iceland by means of the Isaac Newton.

Wouter Vermeersch, Manager Offshore Cables at Jan De Nul Group: “We are delighted for Jan De Nul Group to be selected as the cable repair contractor for TenneT’s HV cable system. This agreement continues our trusted relationship with TenneT and furthers Jan De Nul’s position as a reliable and experienced cable installation contractor.”