The UK energy regulator Ofgem has launched a tender valued at approximately £3.5 billion for the offshore transmission assets associated with Hornsea 3, one of the world's largest offshore wind farms currently under construction.

The competitive process, announced on 21 October 2026, forms part of Tender Round 14 (TR14) under the Offshore Transmission Owner (OFTO) regime and is expected to be the largest tender round since the framework was introduced in 2009.

The selected investor will be responsible for acquiring, operating and maintaining the infrastructure connecting Hornsea 3 to Great Britain's onshore electricity network, including submarine cables and offshore and onshore substations.

Under the OFTO framework, successful bidders receive a long-term, inflation-linked revenue stream in exchange for financing the acquisition and managing the transmission assets.

Hornsea 3 expected to supply electricity to 3.3 million homes

The Hornsea 3 offshore wind farm, located more than 100 kilometres off the British coast in the North Sea, is currently under construction and is expected to be completed by the end of 2027.

According to Ofgem, once operational, the wind farm is projected to generate enough electricity to supply the equivalent of 3.3 million UK homes.

The transmission infrastructure covered by the tender will enable electricity generated offshore to be transported to the onshore transmission network.

The tender concerns the ownership and operation of these transmission assets, rather than the construction or ownership of the wind farm's electricity-generating facilities.

Investors to compete for long-term transmission asset ownership

The OFTO regime was established to introduce competition into the ownership and operation of offshore electricity transmission infrastructure.

Under this framework, transmission assets are developed and constructed before their ownership is transferred to an investor selected through a competitive tender.

Successful bidders receive long-term revenues linked to inflation, subject to the obligations established under the regulatory framework, to finance, operate and maintain the infrastructure.

Ofgem considers that competition between potential owners helps control transmission costs while maintaining operational performance and reliability.

Beatrice Filkin, Ofgem's Director of Major Projects, highlighted that the transmission connection serving Hornsea 3 will enable electricity generated offshore to reach millions of British consumers.

She also explained that the competitive tender is intended to attract private investment into electricity infrastructure while supporting cost efficiency for consumers.

Ofgem has invited potential investors interested in participating in the tender to obtain further information about the process.

OFTO framework has attracted more than £10 billion in investment

Since the OFTO regime began in 2009, winning bidders have invested more than £10 billion in transmission connections serving 28 offshore wind farms, according to Ofgem.

The framework separates the ownership and operation of offshore transmission infrastructure from the generation assets themselves.

This allows specialist investors to acquire and manage transmission networks under regulated conditions, while offshore wind developers focus on the development and operation of their generation projects.

The new £3.5 billion tender represents a further application of this approach as additional offshore wind capacity is connected to Britain's electricity system.

Transmission investment to support electricity demand growth

Ofgem links the development of offshore transmission infrastructure to the wider modernization of Great Britain's electricity system.

The regulator highlights that electricity demand is expected to increase as transport, heating and industrial activities become more electrified, alongside the expansion of energy-intensive sectors such as data centres.

In this context, offshore transmission connections are necessary to integrate renewable electricity generation into the national grid and transport power from offshore wind farms to consumers.

The regulator also considers that expanding the use of domestic renewable energy resources can reduce reliance on imported fuels and exposure to fluctuations in international gas markets.

With Tender Round 14 now launched, Ofgem will oversee the competitive selection of an investor to take ownership of the transmission assets associated with Hornsea 3.