How the UK is building giant floating wind farms in the Celtic Sea

Ocean Winds has been given the rights to develop a floating offshore wind site in the Celtic Sea with a capacity of up to 4.5 gigawatts (GW), the government announced in its Industrial Strategy quarterly update published in April 2026. The same update confirmed a UK-Japan investment deal on clean energy projects.

What is floating offshore wind?

Most wind farms are built in shallow coastal waters, where turbines sit on fixed concrete and steel foundations anchored to the seabed. In deeper waters — beyond the continental shelf — this becomes too expensive. Floating wind works differently: turbines are mounted on platforms held in place by moored cables, rather like oil rigs. This technology allows wind farms to be built in much deeper water where the wind is stronger and more consistent.

The Celtic Sea, which spans the waters off Wales, south-west England and Ireland, is deep enough that floating platforms are the only practical option. A single site producing 4.5 GW — if fully built — would rank among the world's largest floating wind projects at this stage of the technology's development.

The political geography

Offshore wind licensing is decided by Westminster. But onshore grid connections, planning permissions for related infrastructure and how local economies benefit involve the Welsh Senedd (parliament) and, for parts of the Irish Sea, considerations that affect UK relations with Dublin. All three governments will need to work together as the project progresses.

Japan's role and industrial strategy

Japan has made floating offshore wind a strategic priority because its own deep-water coastline makes fixed-bottom technology unsuitable for most of its exclusive economic zone. Japanese trading companies and energy utilities have been actively looking for stakes in Atlantic floating wind projects. The government's quarterly update did not set out the precise terms of the UK-Japan deal, but pairing it with the Ocean Winds award suggests ministers view both as parts of the same industrial strategy.

The longer timeline

The government's Clean Energy Superpower mission aims for clean electricity across Great Britain by 2030. Floating wind projects take longer to build than fixed-bottom farms because of their complexity. Even if the Celtic Sea site is fully developed, it would likely contribute to Britain's power supply in the 2030s and beyond, rather than help meet the 2030 target.

What still needs to happen

Ocean Winds is a joint venture between EDP Renewables and ENGIE, two large European renewable energy companies. Winning seabed rights is the first step, not the last. The project must still secure a Contract for Difference — a government guarantee of a certain price for the electricity it produces — get grid connection agreements from National Grid ESO, and pass through the planning process for major infrastructure projects under the Planning Act 2008. Each of these stages carries real risks that could slow down or derail the project.

The industrial strategy question

The government frames floating wind as crucial not just for energy security, but as part of building a British clean-energy industry. Supply chain development, port investment and export opportunities are all part of the plan. Whether that vision survives the real-world finance and engineering required to actually build the farms is what developers and investors are now figuring out.