Ofgem has shortlisted five bidders to compete for ownership and operation of offshore transmission links for three North Sea windfarms off the UK’s east coast.

The bidders are vying for assets that connect offshore wind farms East Anglia THREE, Inch Cape and Dogger Bank C into Great Britain’s power grid.

Ofgem added that the 13th tender round features its largest field of bidders since 2019, highlighting growing investor interest in the offshore transmission owner (OFTO) regime.

With a combined estimated value of £3.5bn, the pre-built connections – which consist of onshore and offshore cables, converter stations and substations – connect clean power generated by North Sea wind to the grid providing the ability to power millions of homes and boost the UK’s energy security. 

The shortlisted bidders are:

• Diamond Transmission Partners, formed by Diamond Transmission UK  
• Equitix, formed by Equitix Investment Management  
• Gravis Sosteneo Consortium, a bidder group formed of Gravis Capital Management and Sosteneo Fund II HoldCo S.à.r.l.  
• John Laing, a bidder group formed of Laing Investments Management Services and John Laing. 

• Transmission Capital Partners, a bidder group formed of International Public Partnerships, Transmission Capital Partners Partnership and Transmission Investment Holdings 

The five bidders will now be invited to submit their formal tenders ahead of Ofgem selecting a preferred bidder for each project, who will ultimately be issued with a transmission licence to operate one or more of the three OFTOs.

Since its launch in 2009, the OFTO regime has seen winning bidders invest over £10bn in links connecting 28 offshore wind farms. As the race to achieve clean power intensifies, Ofgem anticipates bringing as much as £6bn of OFTO assets to market each year in the run up to 2030. 

Later this year Ofgem plans to launch Tender Round 14. While the specific assets have not yet been confirmed, Ofgem encourages parties interested in participating in future OFTO competitions to get in touch for information and support.

Beatrice Filkin, Ofgem’s director of major projects, said: “Recently, we’ve seen how geopolitical events can impact both energy security and investments.  Ofgem’s OFTO regime not only helps boost British energy security but also offers investors a safe and steady asset for their portfolios.

“Through the OFTO regime, Ofgem is attracting vital investment into the UK to support growth and deliver a stable, secure energy system powered by clean electricity, while also ensuring consumers get a good deal.”

East Anglia THREE  is located 69km from the East Anglian coast in the southern North Sea. The wind farm could generate up to 1.4GW with the potential to power more than 1.3m homes. The array forms part of the East Anglia Hub windfarms.

Inch Cape is one of Scotland’s largest offshore wind farms. It comprises 72 turbines located 15km off the Angus Coast in the North Sea and has a generation capacity of almost 1.1GW.

Dogger Bank C is located 196km offshore and has a generation capacity of 1.2GW. It forms part of the world’s largest windfarm (also comprising Dogger Bank A and Dogger Bank B) which will have an installed capacity of 3.6GW capable of powering up to six million homes a year.  

Major projects and issues shaping the future of the country’s infrastructure sector will go under the spotlight at the Delivering Infrastructure 2050 conference being held in London on 30 June 2026.

Organised by the Association for Consultancy and Engineering (ACE), Ofgem’s Beatrice Filkin (pictured above) is among the line-up of speakers who will be sharing their insight of the sector at the event.

A  senior energy infrastructure professional serving as director of major projects at Ofgem, the UK’s energy regulator, Filkin oversees delivery of large‑scale energy transmission and storage initiatives to support the energy transition and clean power goals.

Click here to find out more about the event.