Aberthaw Severn tidal lagoon gets £6.4m exploratory funding, Cardiff 2026

Key Points

• In addition, Cardiff Capital Region (CCR) has sanctioned up to £6.4m in funding towards City Deal, over a three-year period, on exploratory development studies for Severn Estuary tidal lagoon.
• The preferred location of the lagoon is offshore Aberthaw in the Vale of Glamorgan, which is where the CCR owns a 500-acre site that is formerly a power station.
• According to preliminary calculations, the lagoon may be capable of producing around 600MW of renewable electricity that can sustain around half a million households for more than 120 years.
• The lagoon is estimated to contribute around £3.5 billion of economic value in addition to job creation, supply chain opportunities and coastal protection benefits.
• The next stage involves co-design of environment and engineering in order to establish the size and configuration of the lagoon based on ecological evidence in addition to business case.
• The completion of the project will certainly need investment way beyond the capacity of the CCR budget, with the UK Government’s £28 billion National Wealth Fund and institutional investors being identified as future contributors.
• The project is a result of the recommendation by the Severn Estuary Commission and partnership between the CCR and the West of England Mayoral Combined Authority

Cardiff (Wales Times) September 2026 – uk/local/cardiff/">Cardiff Capital Region has formally approved funding for exploratory development studies into a tidal lagoon in the Severn Estuary, marking the first substantive step towards what could become one of the UK’s most significant renewable energy projects. CCR will commit up to £6.4m over the next three years, drawn from its £1.2bn City Deal, to support environmental assessments, engineering design, modelling and commercial evaluations for a preferred location off the Aberthaw coast. The work is intended to establish whether a commercial demonstration project can be delivered in an environmentally responsible, technically deliverable and commercially competitive manner, with the ambition of unlocking a wider series of lagoons across the Severn.

How much energy could the Severn tidal lagoon generate?

Initial estimates suggest a lagoon at Aberthaw could provide around 600MW of predictable renewable electricity, enough to power approximately half a million homes, and operate for more than 120 years. Proponents describe the Severn Estuary as having one of the highest tidal ranges in the world, offering a source of homegrown, predictable power that complements intermittent wind and solar generation. While the current proposal focuses on a single demonstration lagoon, wider scenarios have indicated that a series of lagoons in the estuary could collectively generate enough electricity to meet the needs of up to four million homes.

What are the expected economic and jobs impacts?

As reported by journalists covering the announcement, a lagoon at Aberthaw could generate around £3.5bn in economic value, supporting thousands of jobs and creating significant opportunities for businesses across the supply chain. CCR already owns a 500‑acre site at Aberthaw, having acquired the former Aberthaw Power Station from RWE, and is planning a green energy park that could support construction and operations related to any lagoon. Local leaders have highlighted the potential to attract investment, develop skills and strengthen local supply chains, particularly in South Wales, which has historically played a prominent role in the UK’s energy sector.

Who is backing the Severn tidal lagoon plans?

The project has emerged from joint work between CCR and the West of England Mayoral Combined Authority (WECA), following recommendations from the independent Severn Estuary Commission for a commercial demonstration project. Cllr Mary Ann Brocklesby, Chair of Cardiff Capital Region, described the approval as a “potentially game changing moment for renewable energy generation in the UK”, emphasising energy security and Wales’s opportunity to lead in marine renewables. Adam Price MS, Cabinet Minister for Enterprise, Connectivity and Energy, said the vision is for Wales to become a world leader in marine renewables and that the Severn Estuary presents “immense potential” for renewable generation and economic benefits.

UK ministers also welcomed the move. Katie White OBE MP, Minister for Climate Transition, said the project would help show how tidal technology can contribute to clean power, climate goals and future jobs. Stephen Kinnock MP, Secretary of State for Wales, said Wales has a strong track record of innovation and partnership and that CCR is harnessing those strengths to support growth, investment and clean energy. On the cross‑border side, Helen Godwin, Mayor of WECA, said the Severn Estuary is an “extraordinary natural asset” and that tidal energy can unlock billions for the economy and create new jobs and skills across the West of England, Wales and the wider UK.

What studies will the £6.4m funding support?

The approved £6.4m will fund an extensive exploratory study covering environmental considerations, engineering design, modelling and commercial assessments over three years. The next phase will use environmental and engineering co‑design to determine the scale and configuration of a potential project, ensuring that marine and ecological evidence helps shape future development while maintaining commercial viability. Dr Andrew Garrad CBE FREng, who chaired the Severn Estuary Commission, said the estuary has immense energy potential but must be developed “in the right way”, with the internationally important environment at the heart of design and development. He described CCR’s investment as an important next step in building evidence and working closely with environmental organisations.

How will the Severn tidal lagoon be funded beyond exploratory work?

Taking a lagoon through planning is expected to cost tens of millions of pounds, with construction costs well above £1bn, beyond the reach of CCR alone. If the project proceeds to the next phase, the UK Government’s £28bn National Wealth Fund could be a potential investor alongside institutional pension funds. A regulated asset base model has also been discussed, under which upfront construction costs could be partly funded through a contribution made via consumer energy bills.

CCR is financing the early‑stage work from its City Deal and has adopted an “evergreen” funding strategy, whereby capital and interest payments from projects are recycled into further investments; its contribution could see it taking an equity stake in the lagoon.

Why Aberthaw and what is the wider Severn lagoon vision?

The Severn Estuary Commission identified Aberthaw and its surrounding area as a potential location for a commercial demonstration lagoon, with the intention that a successful project would establish a precedent for further developments. As a preferred location, Aberthaw is seen as the right site to lead with while ensuring the unique environment of the coast remains central to plans. The demonstration project is intended to provide evidence that tidal range on this scale can be environmentally responsible, technically deliverable and commercially competitive, unlocking a wider series of lagoons across the Severn. Previous large‑scale proposals, including the Swansea Bay Tidal Lagoon scheme, failed to secure subsidy backing from the UK Government in 2018, and a more ambitious Severn barrage was ruled out by the commission in its report last year.

Background to the Severn Estuary tidal lagoon development

Interest in harnessing the Severn Estuary’s tidal range dates back decades, with multiple proposals for barrages and lagoons examined over the years. The Swansea Bay Tidal Lagoon scheme, once seen as a pathfinder, did not proceed after the UK Government declined subsidy support in 2018, leaving the wider Severn tidal energy concept in abeyance. More recently, the independent Severn Estuary Commission, established to explore how to unlock the estuary’s potential responsibly, recommended a commercial demonstration project as the most viable route forward, while ruling out a full Severn barrage. That recommendation, developed through joint work between CCR and WECA, has now led to the approval of £6.4m in exploratory studies focused on Aberthaw, with the aim of building the evidence base needed to attract larger public and private investment.

Prediction: how could this development affect energy consumers and local communities?

If the exploratory work confirms technical and commercial viability, the Severn tidal lagoon could affect energy consumers and local communities in several ways. For consumers, the project promises predictable, long‑life renewable generation that could contribute to a more stable, diversified electricity mix, potentially reducing reliance on more volatile fossil‑fuel generation over time. For local communities in South Wales and the wider Severn region, the development could bring thousands of jobs during construction and operation, stimulate supply‑chain businesses and support skills development in marine renewables.

However, any future financing model that involves consumer bill contributions, such as a regulated asset base approach, would mean households ultimately share some of the upfront costs, making the final impact on bills dependent on the structure of investment and returns. Environmental safeguards and co‑design processes are intended to mitigate ecological risks, but the scale of infrastructure means that detailed assessments and ongoing monitoring will be critical to maintaining public support and regulatory approval.