The Celtic Sea Offshore Wind Opportunity
The Celtic Sea, situated between the southern coast of Wales and the southwest of England, is a new area of offshore wind development in the UK, and has the potential to deliver over 16GW of renewable energy through the deployment of offshore wind farms.
The development, construction, operation and maintenance of these wind farms could create significant opportunities for businesses in the region, leading to the creation of thousands of skilled, well-paid jobs.
Floating offshore wind (FLOW) and deepwater wind technologies mean wind farms can be deployed in deeper waters, where winds are more consistent, resulting in more consistent energy generation.
Floating offshore wind is recognised in the UK’s Modern Industrial Strategy under the Clean Energy Industries mission to create significant investment and job creation opportunities and play a vital part in meeting Wales and the UK’s Net Zero targets.
The Crown Estate, who manage the seabed, has introduced a stepping stone approach to leasing areas of the Celtic Sea for floating offshore wind development.
The first three stages are:
Stage 1: Test & Demonstration
Stage 2: LEASING ROUND 5
Stage 3: additional capacity to be leased by 2030
stage 1: Test & Demonstration projects
Test & Demonstration (T&D) projects, also referred to as stepping-stone projects, are the first piece of the puzzle when it comes to the Celtic Sea – we cannot deploy hundreds of turbines as part of large-scale windfarms without deploying a single turbine first.
These projects will ensure a stepping-stone approach for local businesses, offering them the opportunity to scale-up with industry and compete for contracts on the larger commercial-scale projects likely to be deployed in the 2030s.
There are currently five proposed Test & Demonstration projects in development, totalling more than 400 Megawatts:
TwinHub, developed by Hexicon
The 32 megawatt (MW) TwinHub project will be deployed within the existing Wave Hub site, approximately 16km off the coast of Hayle in Cornwall.
It will connect to the existing cable tails, which run into the Hayle substation, making full use of what has already been installed, and could power up to 45,000 homes.
Erebus, developed by Blue Gem Wind
100 MW project Erebus is a Blue Gem Wind development site located 35km of the coast of Pembrokeshire.
The finished wind farm could have as many as seven floating turbines, enough to power over 90,000 homes.
White Cross, developed by Flotation Energy and Cobra Group JV
White Cross is a 100MW floating offshore wind project which plans to deploy technology 52km off the North Devon coast.
There will be up to eight wind turbines mounted on floating substructures, providing enough energy to power over 135,000 households.
Llŷr 1 & 2, developed by Floventis
The Llŷr 1 and Llŷr 2 projects make use of two separate 100MW sites located south of Pembroke, on the UK’s Welsh coast.
Each will test new floating platform and mooring technologies and explore innovative designs, materials and construction approaches.
stage 2: FLOATING OFFSHORE WIND LEASING ROUND 5
In June 2025, the preferred bidders for PDA (Project Development Area) 1 and 3 were announced by The Crown Estate. Each developer has been awarded the opportunity to develop up to 1.5 GW of floating offshore wind capacity, enough to power up to 1 million homes each.
PDA 2 will be progressed through delivery arrangements which will be detailed by The Crown Estate shortly.
For more information, visit The Crown Estate’s Floating Offshore Wind Leasing Round 5 webpage.
The Crown Estate’s Floating Offshore Wind Leasing Round 5 webpage.
PDA 1
Gwynt Glas
Gwynt Glas is a 50:50 joint venture between EDF Renewables UK and ESB. The partnership is also working with DP Energy's Pembrokeshire based team, an exclusive development partner in the project, to leverage their deep knowledge of local stakeholders and continuing work with educational institutions to promote skills and economic opportunities in Wales.
PDA 3
Equinor
Equinor is an international energy company committed to long-term value creation in a low-carbon future. Equinor has been a reliable energy partner to the UK for over 40 years, providing a stable supply of oil and gas, developing the UK’s offshore wind industry, and pioneering solutions to decarbonise the UK economy.
stage 3: future developments
In 2024, The Crown Estate and Great British Energy announced a new partnership to utilise the strengths of both organisations to bring to market an additional 20-30GW of offshore wind leasing opportunity by 2030 – enough to power almost 20 million homes across the UK. Much of that new capacity is expected to be in areas of the Celtic Sea.
In its Future of Offshore Wind report launched in September 2024, The Crown Estate said 4-10GW of the 12GW spatial potential previously outlined, could be leased by 2030 and in operation from 2035 to 2040.
The Crown Estate is working closely with marine users through their Marine Delivery Routemap to ensure there is a balanced approach to future seabed leasing in the Celtic Sea.
the celtic sea timeline
2019
- Sites identified in Celtic Sea & Scotland for Demo Projects.
2022
- The Crown Estate announce intentions for the first commercial FLOW leasing round and announce the five areas they plan to research in the Celtic Sea.
2023
- Erebus, Wales’ first FLOW development is granted the necessary permissions by Welsh Government to proceed with the project.
2024
- Floating Offshore Wind Leasing Round 5 opens.
- National Grid ESO publish their recommendation on where the project development areas are likely to to connect to the UK’s electricity grid.
2025
- Floating Offshore Wind Leasing Round 5 preferred bidders announced as Gwynt Glas and Equinor.
what could the celtic sea look like in the future?
Celtic Sea Leasing Round 5 is one of the largest floating offshore wind initiatives in the world and could deliver three floating wind farms with a combined output of 4.5GW.
But what does 4.5GW look like?
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260+ floating wind turbines
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Enough power for up to four million homes
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More than 500km of cables to connect turbines to the grid
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Over 1,000 anchors and moorings
the Challenges and opportunities
Developments in the Celtic Sea offer immense opportunities to Welsh businesses and communities, with challenges still to overcome.
The Opportunities
Well-Paid Jobs
The developments in the Celtic Sea are set to create local skills and job opportunities, with the first 4.5GW of floating offshore wind predicted to create more than 5,300 jobs during the construction phase¹.
Economic Growth
Local investment could be seen through local supply chain opportunities with the first 4.5GW of floating offshore wind is predicted to generate approximately £628 million in supply chain spending and deliver £1.4bn GVA to the UK¹.
Environmental Value
Celtic Sea developments have the potential to contribute towards the CO2 emissions reduction required to meet the UK’s Net Zero targets² and unlock energy in new, previously untapped areas offshore.
The Challenges
Port Investment
Investment in the Celtic Sea ports should be seen as a key strategic priority, recognising the importance of their role in the deployment of offshore wind and the development of domestic, sustainable and short supply chains.
Grid Infrastructure
Grid capacity remains a major barrier to the long-term success of the Celtic Sea. A coordinated network design that keeps pace with future leasing rounds could fully maximise the potential of the Celtic Sea with projects delivered on time, with benefits being seen in the region.
Future Leasing Rounds
Clarity over the extent of future leasing rounds will help provide investor confidence, at present, there is too much uncertainty which creates commercial risk and prohibits investment.
Test & Demonstration Revenue Support
Targeted revenue support for the development of the Celtic Sea T&D projects and associated infrastructure is needed to support the delivery of both Celtic Sea T&D projects and essential regional infrastructure.
CSDA
The Celtic Sea Developers Alliance brings together world-leading energy and renewables developers who are driving the development and roll-out, of FLOW in the Celtic Sea.
Collectively, the CSDA can offer unparalleled insight, experience, and expertise into how to make the Celtic Sea development a success. It promotes the opportunity and acts as a single voice to influence government policy and strengthen stakeholder engagement.
Marine Energy Wales is proud to be part of the Celtic Sea Cluster, which was established to help drive market creation for floating wind, accelerate supply chain edginess and develop a strategy for enhancing regional infrastructure.
