DeepOcean to Install Inter-Array Cables at RWE’s Nordseecluster Offshore Wind Farms

Wind Farm Update

August 14, 2023, by Adrijana Buljan

RWE has selected DeepOcean as the preferred supplier of inter-array cable installation for the Nordseecluster A offshore wind project, the first of the two phases of RWE’s Nordseecluster development in the German part of the North Sea. The contract could also see the subsea services provider performing the same work on the second, Nordseecluster B phase.

Under the preferred supplier agreement – and the subsequent firm contract which is subject to RWE reaching the final investment decision (FID) for the project – DeepOcean will install 185 kilometres of 66kV inter-array cables that will connect 44 offshore wind turbines at Nordseecluster A, with offshore installation expected to be carried out in 2026.

The agreement also involves the company providing three vessels to undertake the work, including an installation vessel, trenching vessel, and a walk-to-work (W2W) vessel.

The full scope of work under the contract includes project management and engineering; offshore preparation work including pre-installation cable route survey, route engineering and burial assessment, offshore trenching, boulder relocation, foundation preparatory work and offshore substation preparatory work; transport and installation of inter-array cables including burial, pull-in, monitoring and testing; as well as seabed surveys and monitoring.

RWE’s 1.6 GW Nordseecluster is a two-phase development consisting of four wind farm sites in the eastern part of the German North Sea that will together comprise a minimum of 104 wind turbines.

The two Nordseecluster A wind farms will have a combined capacity of 660 MW and the project is currently in the permit application phase. RWE secured the N-3.7 and N-3.8 sites for Nordseecluster A in 2021. The second phase, Nordseecluster B, will add 900 MW of capacity installed across two more wind farms at sites N-3.5 and N-3.6, which RWE just secured in the latest tender round held in Germany.

“We are very excited about supporting RWE’s plans for the Nordseecluster, where the merger of the four sites offers attractive economies of scale and allows the supply chain to reliably plan and leverage synergies. Awarding the contract for the initial phase with the opportunity to provide our services for Nordseecluster B will allow us to significantly reduce project execution risk. This is a risk-reducing measure that will benefit both RWE and us suppliers”, said Øyvind Mikaelsen, CEO of DeepOcean.

Earlier this year, RWE and Northland Power, which has since exited the Nordseecluster project ownership, selected Hellenic Cables as the preferred supplier of the inter-array cables for Nordseecluster.

Last month, the Greek cable manufacturer, together with Jan De Nul Group, was also awarded a contract by TenneT to deliver three HVAC offshore grid connection cables for the Nordseecluster A offshore wind farms.

Nordseecluster A is expected to enter commercial operation in early 2027 while Nordseecluster B is scheduled for commissioning in 2028/2029.

All four Nordseecluster offshore wind farms will feature Vestas 15 MW wind turbines installed on monopile foundations to be manufactured by Dajin Offshore.