UK’s first tidal lagoon could be answer to reliable renewable energy, experts find

An independent commission has concluded that producing tidal energy in the Severn Estuary is "feasible" and could deliver predictable, renewable electricity, whatever the weather conditions.

The Severn Estuary Commission is made up of internationally recognised engineers, financiers, and scientists. They spent a year gathering evidence from hundreds of individuals and organisations to determine if generating tidal power from the Severn Estuary could work.

This renewable works by transforming the energy generated by the movement of the tides into electricity. Since the tides are constant, this source is reliable, unlike other green energy options such as wind and solar.

It’s been estimated that the estuary, which flows into the Bristol Channel between south-west England and south Wales, could produce up to 7% of the UK’s electricity needs.

To harness this energy without damaging natural habitats, the commission has recommended the development of a tidal lagoon as a commercial demonstration project.

With UK electricity demand set to more than double by 2050, the commission has called for urgent investment to make sure tidal energy can play a part in a sustainable future energy system.

Needs careful consideration

Speaking at the launch of the commission's recommendations, Professor Jim Hall, ICE President, described the findings as “a hugely significant examination” into the tidal range potential of the Severn.

“Tidal range energy is well understood. As a technology, it’s proven. As a power source, it’s predictable,” he said.

“With the highest tidal range in Europe, and the second highest in the world, tidal power in the Severn Estuary needs careful consideration.”

Professor Hall highlighted the ICE's flagship report, State of the Nation 2025, which explores the potential of tidal power.

“There’s a case to be made,” he said. “But it requires a capacity to control costs, look to the long-term, and address environmental impacts very early in the conversation, as the Severn Estuary Commission has done.”

Predictable renewable energy

The Severn Estuary Commission was set up by Western Gateway, a partnership of the 28 local authorities across South Wales and Western England.

Sarah Williams-Gardener, chair of the Western Gateway, said: “After many years of debate, we now know that the huge potential of tidal energy in the Severn can and should play a key part in our energy supply.

“We need urgent action to make the most of this opportunity. A lagoon project would not only deliver predictable renewable energy, it could also add up to £12 billion GVA to the UK economy and 220,000 job years in the construction phase.”

The commission’s recommendations report was launched at the ICE’s headquarters, One Great George Street in London on 19 March 2025. The event was supported by ICE Knowledge, ICE South West, ICE Wales Cymru and the South West Infrastructure Partnership.

The full recommendations and detailed findings on environmental, financial, socio-economic and engineering aspects of tidal range energy in the Severn Estuary are available on the commission's website.

Read the full recommendations