Energy and marine consultancy ABL has been appointed by the German transmission system operator (TSO) 50Hertz to provide marine warranty survey (MWS) services for the Ostwind 4 offshore grid connection project in the German Baltic Sea.
Ostwind 4 is a 2 GW grid connection that includes an offshore converter platform, an onshore converter station and a 110-kilometre DC cable system.
The project will use high-voltage direct current (HVDC) technology and will mark the first deployment of a 525 kV HVDC transmission system in the German Baltic Sea. 50Hertz awarded the contract to build and install the Ostwind 4 converter stations to Drydocks World and GE Vernova in 2024. NKT will provide the onshore connections and offshore cable systems under a contract signed with 50Hertz in September 2023.
Under its new contract, ABL will provide independent marine warranty survey services for the transportation and installation of the subsea cables and offshore infrastructure, as well as the installation of the offshore converter platform and associated assets.
The company’s Hamburg-based team will review and approve technical documentation and procedures, provide marine risk and assurance services to assess the suitability of the proposed marine spread, and provide on-site attendance to witness and approve all warranted operations.
The Ostwind 4 contract follows ABL’s recent appointment to provide marine warranty survey and marine assurance services for the 976.5 MW Gennaker offshore wind farm in the German Baltic Sea. The scope of that contract includes the marine transportation and installation of the project’s foundations and other offshore infrastructure.
Ostwind 4 is located about 30 kilometres northeast of Rügen Island and will connect the 1 GW OstSee Energies offshore wind farm, developed by TotalEnergies, to the mainland. OstSee Energies is planned to be built at the O-2.2 site in the German Baltic Sea, between the Arcadis Ost 1 and Baltic Eagle wind farms, which are connected via Ostwind 2.