Ofgem has launched a tender estimated at £3.5 billion for investors to own and operate the transmission infrastructure connecting the Hornsea 3 offshore wind farm to Britain’s electricity grid.
Tender Round 14 opened on 21 October 2026 and is expected to be the largest round under the regulator’s Offshore Transmission Owner regime, known as OFTO.
The competition covers the wind farm’s grid connection assets, including cables and offshore and onshore substations. It concerns ownership and operation of the transmission infrastructure, rather than the wind farm’s generating assets.
Hornsea 3 is under construction more than 100 kilometres offshore in the North Sea. The project is due for completion by the end of 2027 and is projected to generate electricity equivalent to the needs of 3.3 million UK homes.
Investors compete for long-term transmission revenues
Under the OFTO framework, successful bidders finance, operate and maintain transmission assets that have already been built.
In return, they receive a long-term, inflation-linked revenue stream. The arrangement gives investors responsibility for maintaining the connection between offshore generation and the onshore electricity network.
Ofgem uses a competitive tender to select the transmission owner. The regulator says competition is designed to reduce costs for consumers while maintaining performance standards.
The estimated £3.5 billion value relates to the transmission tender. It is not the construction cost of Hornsea 3 as a whole or a funding award announced at the launch.
Ofgem’s announcement did not specify the revenue period for this tender, the bidding timetable or the expected date for appointing a preferred bidder.
Beatrice Filkin, Ofgem’s director of major projects, said the connection would support electricity supplies from Hornsea 3 while offering a long-term investment opportunity.
“By running a competitive process, Ofgem is helping attract the investment Britain needs for a cleaner, more secure energy system while making sure consumers get value for money,” she said.
Hornsea 3 connection expands offshore transmission investment
The OFTO regime has attracted more than £10 billion of investment from winning bidders since its launch in 2009, covering connections for 28 offshore wind farms.
At an estimated £3.5 billion, the latest tender represents a substantial addition to that programme. Its final value will depend on the tender and the assessment of the assets being transferred.
The framework separates the long-term ownership of offshore transmission infrastructure from electricity generation. For investors, the opportunity centres on operating the connection and meeting the associated performance requirements.
For the electricity system, the cables and substations provide the route through which offshore generation reaches the onshore network. Their availability is therefore essential to delivering electricity from the wind farm to consumers.
The 3.3 million homes figure is an estimate of equivalent electricity supply. It does not mean Hornsea 3 will supply a fixed group of households or produce the same output continuously.
Tender supports wider grid expansion
Ofgem places the tender within the broader expansion of Britain’s electricity infrastructure as demand changes across transport, heating, industry and data centres.
Connecting offshore wind capacity is one part of that work. Electricity delivered to shore must also move through the onshore network to reach areas of demand.
The regulator said greater use of domestic renewable resources would strengthen energy security and reduce exposure to volatile international gas markets.
The announcement does not quantify a household bill saving from the Hornsea 3 tender. The consumer value of the OFTO process will depend on the outcome of competition, the revenue arrangements and the owner’s performance over the operating period.
Ofgem has invited prospective investors to contact it for further information about participating in Tender Round 14.
