Offshore construction has officially started at RWE’s 1400MW Sofia Offshore Wind Farm on Dogger Bank, in the central North Sea off the coast of north-east England.
Cable contractor Prysmian’s high-tech Leonardo da Vinci vessel (pictured) will lay the first section of high voltage direct current (HVDC) export cable, ready to transport power from the wind farm back to the UK coast.
The work marks a significant milestone for the project, with Sofia representing a more than £3bn investment in the UK’s energy infrastructure by RWE. The wind farm will make a significant contribution towards the country’s net zero targets said the developer, and be capable of generating enough clean electricity equivalent to meeting the needs of over 1.2m typical UK homes.
“Sofia is RWE’s largest renewable construction project to date, and its furthest from shore,” said chief executive RWE offshore wind Sven Utermöhlen.
“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.
“Building a project of this size and scale is a great opportunity to demonstrate our expertise in delivering offshore wind energy around the globe.”
Sofia Offshore Wind Farm is 195km from the nearest point on the UK’s north east coast, and will have a single offshore converter platform, with the electricity generated transported to landfall 220km away in Redcar, Teesside.
The wind farm will use 100 Siemens Gamesa 14MW turbines (SG 14-222 DD) and is scheduled to be completed by the end of 2026. Forty-four of the project’s 100 turbines will be equipped with recyclable blades.
Operations and maintenance activities for the site will be located at RWE’s new offshore wind operations base in Grimsby, which will also support the developer’s Triton Knoll offshore site and future projects.
Prysmian’s 170-metre-long vessel will operate out of the Port of Middlesbrough and will lay two 130km sections of cable in parallel.
It will start its cable laying work from just off the Teesside coast between Redcar and Marske-by-the-Sea. One end of each of the two sections of subsea cable will be pulled underwater from the vessel through cable ducts that were installed earlier this year.
The cable will pass below the beach, sand dunes and road before emerging at the landfall construction compound. The cutting-edge vessel will then move away from the coast, laying the full length of cable along its set route towards the offshore wind farm.
Installation of two remaining 90km sections of wire is planned for 2024. By late 2024, Leonardo da Vinci will have laid four sections of ±320kV HVDC marine export cables with XLPE insulation, totalling 440km plus the accompanying communications cables.
Onshore building has been underway in Teesside since June 2021, to install the project’s onshore converter station and cable corridor. The laying of the first sections of export cable marks the start of a three-year offshore construction phase.
The ongoing offshore works will include the arrival of the project’s offshore converter platform, due to make the journey from Batam, Indonesia, to the UK in 2024. Also planned for next year is the start of installation of the 100 extended monopile foundations and array cables.
“RWE has 10 offshore wind farms already operating around the UK, and is a leading partner in the generation of clean energy that will help ensure security of electricity supply,” Said RWE’s UK country chair Tom Glover.
“This major construction milestone at Sofia further demonstrates our enviable expertise in offshore wind, which has been pioneered over 20 years in the UK.
“The UK remains of significant strategic importance to RWE.
We are continuing to drive our ambition to grow green through a strong future development pipeline, which will play a key role in delivering our own and the country’s future net zero ambitions.”
RWE has a strong UK pipeline and is involved in four of the UK’s seven offshore wind extension projects, plus two Round 4 Dogger Bank South projects. The company is also exploring offshore floating wind projects, including in the Celtic Sea region.