RWE Renewables has signed a preferred bidder agreement with Italian cable company Prysmian for the supply and installation of HVDC export cables for the 1.4GW Sofia project on the UK Dogger Bank.

The turnkey contract covers 440km of 320kV submarine export cables and 15km of 320kV land cables. The wires will run for 227km between Sofia’s offshore substation and the project's onshore converter station in Teesside.

The deal has a value over £200m but is subject to final negotiations and RWE taking a final investment decision on Sofia.

The offshore cables will be installed by new 170-metre long cable lay vessel Leonardo Da Vinci (pictured), which is currently under construction and will join Prysmian’s fleet next year.

“We are delighted to announce the selection of world leading cable supplier Prysmian as our preferred bidder for this package and confirm the project will be the first to use their latest HVDC cable technology and the cutting-edge Leonardo da Vinci,” said RWE Renewables offshore wind chief operating officer Sven Utermöhlen.

“Today’s signing is another tangible step for RWE Renewables’ Sofia as the project progresses towards a final investment decision in early 2021 and is set to make a major contribution to the UK’s climate goals.”

Onshore construction will get underway at Sofia’s onshore converter station on Teesside next year. The offshore cables will be installed and commissioned in 2024.

“We are honoured to support RWE Renewables in this important offshore wind project, providing our state-of-the-art cable technology to support UK’s sustainable energy system towards the country’s net-zero emission target,” said executive vice president of Prysmian’s project business Hakan Ozmen.

Submarine cables will be fabricated at Prysmian’s plant in Pikkala, Finland, while onshore lengths will be made at the company’s Gron plant in France.

Onshore cables will use 100 percent recyclable P-Laser insulation, with offshore lengths opting for XLPE insulation.