RWE has begun offshore construction for its Sofia wind farm with the laying of the first section of the high-voltage direct current export cable.
The 1.4GW wind farm will be located 195km off the coast of north east England on the North Sea’s Dogger Bank although the cable will make landfall 220km away from its offshore converter platform at Redcar in Teesside.
The wind farm will feature 100 of Siemen Gamesa’s 14MW turbines with 108m-long blades and a rotor diameter of 222m. The blades on 44 of the turbines will be recyclable. RWE is investing £3 billion in the flagship project, which is scheduled for completion in 2026.
The export cables will be laid by Prysmian’s Leonardo da Vinci vessel operating out of the Port of Middleborough. This work is expected to be completed by late 2024. The installation of the monopile foundations for the turbines and the array cables is due to begin next year.
Operation and maintenance activities will take place from RWE’s new offshore wind operations base in Grimsby, which will also support the company’s Triton Knoll offshore wind farm as well as other future project in the North Sea.
Sven Utermohlen, chief executive of RWE Offshore Wind, said: “Sofia is RWE’s largest renewable construction project to date, and its furthest from shore. The project is setting new standards in terms of addressing innovation, sustainability, and engineering challenges.
“The laying of the first section of export cable represents the culmination of 13 years of planning, preparation, and diligence, as well as a huge amount of support from suppliers and stakeholders alike.”
Sofia was originally developed by the Forewind consortium – comprising RWE, SSE, Statkraft and Equinor (then Statoil) – as one of a series of eight offshore wind projects on Dogger Bank that were expected to deliver 9GW of capacity.
The consortium scrapped two of the projects in 2014 and then another two in 2015 shortly after the secretary of state awarded a development consent order for the remaining four, each of which was expected to have a capacity of 1.2GW. RWE’s share in the development was handed to its new subsidiary Innogy as part of its formation in 2016.
In March 2017, Statkraft decided to leave the Forewind consortium, selling its 25 per cent stake to SSE and Equinor. The following August, Innogy took full control of one of the projects and subsequently renamed it Sofia. It left SSE and Equinor to develop the other three Dogger Bank projects.
Innogy secured Contract for Difference for Sofia at a strike price of £39.65/MWh (2012 prices) in the third allocation round in September 2019 after receiving consent to increase the size of the project to 1.4GW earlier in the year.
The company’s renewable assets, including Sofia, were returned to RWE in July 2020 as part of a major asset swap deal that saw Innogy sold to Eon. RWE gave the final go-ahead to the project in March 2021 and begun onshore construction three months later.
In July last year, RWE secured seabed leasing rights for two further offshore wind farms on Dogger Bank in the Crown Estate’s fourth offshore leasing round. The company said the two projects could provide up to 3GW of generation capacity.