2GW offshore substations lined up for North Sea

The high-voltage direct current (HVDC) systems will each have a transmission capacity of 2GW, which could be sufficient to power 35 million households, when the wind blows.

The 2GW Program, which is being implemented by the Dutch transmission system operator TenneT,  will be helped along by marine contractor Heerema, which has been signed up along with Allseas to transport and install 14 jackets and 14 topsides for the platforms.

Heerema will deploy semi-submersible crane vessel Sleipnir, as well as an owned floatover barge, for the installation of the jackets and topsides. These unique assets are suited to installing the heavy offshore wind infrastructure associated with the 2GW program.

Sleipnir, which can run on LNG, has previously installed the Hollandse Kust Alpha and Beta jackets for TenneT in the Dutch North Sea.

She has two cranes, each with lifting capacity of 10,000t, and a reinforced deck area of 220m x 102m. As well as installing jackets and topsides, Sleipnir can install foundations, moorings and structures in deep water.

“The award of this framework agreement is an important showcase of the benefits of forming trust-based partnerships between clients and contractors,” said Jeroen van Oosten, Heerema’s chief commercial officer. “To ensure clean energy demands are met, there should be a continued focus on collaborative, forward-looking agreements that recognize the need to secure transport and installation capacity.”

TenneT operates more than 25,000 kilometres of lines and cables in the Netherlands and Germany.