Cardiff Capital Region (CCR), the regional economic development body for South East Wales, is beginning an exploratory phase for a potential tidal lagoon in the region.
CCR has approved exploratory development studies for a tidal lagoon within the Severn Estuary, said to have one of the highest tidal ranges in the world, reaching up to 14.5 meters, with initial analysis suggesting that a lagoon at Aberthaw could generate around 600 MW, potentially generating approximately 1.3 TWh of renewable electricity each year, enough for approximately half a million homes.
Economic analysis estimates that the development and construction of the tidal lagoon could generate around £3.5 billion in UK economic value and support thousands of jobs.
Using City Deal funds, CCR will commit up to £6.4 million over the next three years to support the first substantive phase of the project, including an extensive exploratory study that covers environmental considerations, engineering design, modelling and commercial assessments.
The next step is to develop the evidence needed to understand whether an Aberthaw tidal lagoon is technically, environmentally, commercially and economically viable. This will include engineering and environmental co-design, hydrodynamic modelling, surveys and investigations, environmental assessment, stakeholder engagement and development of the commercial and business case.
“This represents a potentially game changing moment for renewable energy generation in the UK. The Severn Estuary has one of the highest tidal ranges in the world, with the potential to generate predictable, homegrown renewable energy that complements existing wind and solar power," said Cllr Mary Ann Brocklesby, Chair of CCR.
"If progressed, initial estimates suggest the lagoon could provide around 600MW of predictable renewable electricity – enough for around half a million homes – and operate for more than 120 years. It could also generate around £3.5bn in economic value, supporting thousands of jobs and creating significant opportunities for businesses across the supply chain. Meanwhile, wider potential benefits include long-term protection against sea-level rise along the South Wales coastline."
The Severn Estuary Commission was established in March 2024 to explore tidal energy in the Severn Estuary and to identify the most effective and environmentally responsible way of unlocking its potential.
Following recommendations from the Commission for a commercial demonstration project, the tidal lagoon project is a result of joint work between CCR and the West of England Mayoral Combined Authority (WECA). This joint work examined potential locations across the entire Bristol Channel and Severn Estuary and identified Aberthaw as offering the best overall balance of energy potential and environmental, physical and infrastructure considerations.
“Our vision is for Wales to become a world leader in marine renewables. With the second largest tidal range in the world, the Severn Estuary presents immense potential to deliver significant renewable energy generation and economic benefits for Wales," said Adam Price, Cabinet Minister for Enterprise, Connectivity and Energy.
“We will continue to work closely with partners to ensure we maximise the opportunities offered by this unique project as it progresses forward. The next phase will use environmental and engineering co-design to determine the scale and configuration for a project, ensuring environmental, marine and ecological evidence helps shape its future development while maintaining commercial viability."