Heerema to Deliver Flat-Over Barge for TenneT’s 2 GW Offshore Topsides

January 6, 2025, by Adnan Memija

Heerema Marine Contractors has signed a contract with the German/Dutch transmission system operator (TSO) TenneT for the delivery of a float-over barge, designed to install 2 GW offshore substations weighing more than 30,000 tonnes.

TenneT Heerema — *Source: Heerema Marine Contractors*

According to Heerema, the new float-over barge will be a vital asset in the installation of ultra-heavy topsides, such as TenneT’s 2 GW topsides.

“The Dutch and German governments, on the basis of European climate goals and the desire to become more independent from fossil fuel, have tasked TenneT to expand the national power grids in support of offshore wind energy,” said Dick Lagerweij, responsible for the 2 GW Transport and Installation contracts at TenneT.

“TenneT’s 2GW program is based on standardisation and long-term agreements which allow contractors to invest in time to support and de-risks the program. Vital part of the 2GW grid connections are the DC (Direct Current) offshore power Converters, of which TenneT is planning to install more than 14 in the North Sea. We welcome the investments of Heerema in barges in support of Transport and Installation of these DC Converters.”

The TSO plans to connect 14 HVDC offshore grid connection systems with a transmission capacity of 2 GW each in the North Sea by 2032 – seven in Germany and seven in the Netherlands.

At the end of last year, TenneT selected Denmark’s NKT to provide HVDC on- and offshore power cable systems for two projects in Germany.

The contracts, valued at approximately EUR 1 billion, are set to be completed between 2026 and 2027, encompassing cable design, engineering, production, and both onshore and offshore installation.