- All 100 steel monopile foundation structures have now been installed across the Sofia offshore array on Dogger Bank, 195 km off the north-east coast of the UK.
- Once fully operational, the 1.4 gigawatts project will generate enough electricity to power 1.2 million typical UK homes annually.
RWE, a world leader in offshore wind, has reached a further major construction milestone at its Sofia Offshore Wind Farm, with the successful installation of the 100th and final offshore monopile foundation.
This significant achievement concludes a 14-month foundation installation campaign executed by Van Oord as part of a joint engineering, procurement, construction and installation (EPCI) contract for both wind turbine foundations and array cables.
Photo: Offshore Wind Farm Sofia, Construction Foundation 2025. Source: RWE
Sven Utermöhlen, CEO RWE Offshore Wind: 'The successful completion of monopile installation at Sofia marks a significant milestone in the delivery of this complex offshore wind construction project. This achievement is a testament to the expertise, dedication, and collaboration of the entire RWE team and our partners. Sofia will play a critical role in contributing to the UK’s clean energy transition and reinforcing energy security.'
The 1.4 gigawatts (GW) Sofia Offshore Wind Farm is located 195 kms off the UK east coast in water depths of 20-35 meters and is RWE’s largest offshore project currently under construction globally. Once fully operational, the generation output of all 100 of Sofia’s turbines will be equivalent to powering up to 1.2 million typical UK homes with electricity from wind energy.
The foundations, manufactured by EEW, are state of the art. Rather than using a monopile foundation topped with an overlapping separate transition piece, an extended single monopile is installed and secondary steel fitted offshore. This significantly reduces the total steel tonnage required to complete the project, saving on steel and associated energy resources.
The installation works started in May 2024 using Van Oord’s jack-up vessel ‘Aeolus.’ The vessel underwent a project-specific upgrade to its crane system to achieve a 1,650-tonne lift capacity, enabling it to handle Sofia’s heaviest monopiles. The precision of the installation is critical, as each of the steel cylinders will form a solid base for the massive 14 megawatts (MW) Siemens Gamesa wind 252-metres-tall turbines, half of which are being installed with recyclable blades. The first turbine was installed in March with 27 completed.
During construction, Sofia has deployed a full-scale bubble curtain noise abatement system for 34 foundations – a first for the UK. The technology, operated by Hydrotechnik Offshore, creates a barrier of bubbles that significantly reduces underwater noise during piling operations, helping to protect marine species in the Southern North Sea Special Area of Conservation (SAC).
The installation campaign was carried from the Port of Tyne - the primary storage and marshalling location for all the foundation components. Investment in the infrastructure allowed for the port to accommodate this project and positioned it as a key player for future offshore wind developments in the North East.
With foundation installation complete, Van Oord is now progressing the burial of approximately 360 kms of array cables, with completion expected later this year.
Source: RWE
