TenneT Gathers BorWin5, BorWin6 Offshore Platform Consulting Team

TenneT has awarded several companies and consortia with contracts for consultative engineering and construction services for the offshore transformer stations that will be part of the BorWin5 and BorWin6 offshore grid connections in Germany.

A consortium between Fichtner and SeaRenergy will deliver the services for both platforms, while DNV GL, Lloyd’s Register and TÜV Rheinland have been selected for the platform of the BorWin6 grid connection.

The scope includes design reviews to check, comment and approve designs and documents as part of a project for the delivery and construction of the offshore HVDC converter platforms. 

The project parameters will be checked and documented with regard to their compliance with contractual requirements and required technical specifications, as well as the feasibility of the transport and installation concept with regard to international norms, standards and regulations.

BorWin5, which will connect the EnBW He Dreiht offshore wind farm to the German grid, is the fourth HVDC grid connection project that TenneT will build off the coast of Borkum, following BorWin1, BorWin2 and BorWin3.

With a transmission capacity of 900 MW, the BorWin5 project will consist of the offshore converter platform, BorWin epsilon, and a total of 230 kilometers of cable, 110 kilometres of which will run from the offshore platform to land. The project is scheduled to be operational in 2025.

Last year, TenneT awarded a consortium of Siemens and Dragados Offshore with a contract to build both the onshore and offshore converter stations for the 900 MW grid connection.

With the 930 MW BorWin6 project, the transmission system operator is planning a direct current connection in the North Sea Cluster 7.

Scheduled to be commissioned by 2027, the BorWin6 offshore grid connection will collect the three-phase current generated at an offshore wind farm to be selected in the 2022 auction round.

The three-phase current will then be converted into the direct current on the BorWin kappa offshore converter platform and transported to the mainland in Büsum via an export cable approximately 189 kilometres in length.

In December 2020, TenneT issued a call for tenders for the design, manufacture, installation, and commissioning of the converter stations for the BorWin6 grid link.