East Anglia THREE offshore converter station jacket beds down in North Sea

The foundation for ScottishPower Renewables’ first offshore high-voltage direct current (HVDC) converter station has been successfully installed in the southern North Sea, marking a major milestone for the £4Bn East Anglia THREE offshore wind project.

The steel jacket structure, weighing approximately 3,700 tonnes and standing 59 metres high, has been fixed to the seabed 69 kilometres off the Suffolk coast in waters 36 metres deep. The installation was carried out by Heerema Marine Contractors’ SSCV Sleipnir, the world’s largest crane vessel, following fabrication at Aker Solutions’ Verdal yard in Norway.

The converter station jacket forms a critical component of the 1.4 GW East Anglia THREE scheme, which will be the Iberdrola group’s largest single wind farm on completion and one of the largest globally. Due to enter operation in late 2026, the development will generate enough clean electricity to power more than one million homes.

Project director Pedro Fernandez described the operation as “the biggest feat of engineering we’ve ever undertaken”, highlighting the precision required to lift and place the 3,700-tonne structure on the seabed. He credited the achievement to close collaboration between ScottishPower Renewables and its supply chain partners, including Aker Solutions and Heerema.

The offshore campaign was supported by the tugs Bylgia, Skandi Handler and EEMS Wrangler, together with the guard vessel Tess. Further activity is scheduled throughout the year, including the installation of turbine foundations, progress on the topside for the converter station, and the laying of inter-array cabling to connect the turbines to the offshore platform.

East Anglia THREE is one element of ScottishPower Renewables’ wider East Anglia Hub, which has a combined planned capacity of 3.1 GW. The project is expected to make a significant contribution to the UK’s offshore wind targets while sustaining a large supply chain footprint across fabrication, marine logistics and installation services.

With this latest milestone achieved, the project moves into an intensive phase of offshore delivery that will see multiple contractors active on site in the coming months as work accelerates towards first power.

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