The preferred development zone for what could become the world's largest tidal power scheme has been identified as the stretch of the River Mersey between Bromborough in Wirral and Otterspool in Liverpool.
At a meeting next week, the Liverpool City Region Combined Authority will be asked to approve proposals for a vast tidal power project spanning a 1.5-mile section of the river, encompassing both the Liverpool and Wirral banks.
The decision would allow the project – a long-held ambition of Metro Mayor Steve Rotheram – to advance to the next phase of engineering, environmental and commercial development work, ahead of a future Development Consent Order (DCO) application.
Preferred alignment corridor selected
The preferred location, known as the alignment corridor, was selected following consultation with key stakeholders and a thorough technical appraisal of available options. The appraisal also recommended that further work focus on refining the barrage to align with navigation channels alongside the structure, as well as exploring lock-based alternatives.
No construction will commence until a DCO has been granted and a final investment decision confirmed, reports the Liverpool Echo.
Mayor Steve Rotheram said: "For as long as I can remember, people have talked about harnessing the power of the River Mersey. Identifying where the barrage could be built is a major step forward for a project that has the potential to be genuinely transformational – not just for our region, but for the country.
"At a time when events around the world can send energy prices soaring, we need to make better use of the resources we have on our own doorstep. We should be generating more of our own energy, strengthening our energy security and creating good jobs here at home."
The Mersey has one of the biggest tidal ranges in the country and we have the industrial expertise and the ambition to help do something genuinely world-leading. And with the potential to protect homes and businesses from rising sea levels too, this could be an investment in our region's future that our children, grandchildren and generations beyond them could still be benefiting from a century from now.
Public engagement and funding model
Plans are currently being drawn up for a second round of public engagement in late 2027 or early 2028, which would give local residents and communities the opportunity to have their say and help shape proposals for the scheme.
An initial public engagement exercise in 2024 generated more than 3,000 responses, with 84% backing the project and 92% supporting the need for greater renewable energy production across the Liverpool City Region.
At the same meeting next week, the Combined Authority will also be asked to adopt a Regulated Asset Base (RAB) model as its preferred funding mechanism for the project, following the completion of a Finance Model Update.
A Regulated Asset Base (RAB) funding model is a means of financing large-scale infrastructure projects, such as nuclear power stations, water networks or major transport schemes. Rather than waiting until a project reaches completion before the developing organisation begins recouping its investment, the RAB model permits it to start recovering a portion of its costs from customers during the construction phase.
This approach reduces the financial burden on both investors and the public purse, while delivering stable, regulated returns over time.
Project scale and flood protection
The Mersey Tidal Power Project, if given the green light, is planned to become the largest tidal range power plant in the world, generating up to 1 gigawatt of clean, green electricity for 120 years. The CA says it would create thousands of jobs during its construction and operation, positioning the Liverpool City Region as the "UK's epicentre for tidal manufacturing and associated supply chains."
The River Mersey boasts a tidal range — the difference between high and low tides — of up to 10 metres, the second highest in the UK, alongside a uniquely shaped estuary, leading decision-makers to believe it is ideally suited to the scheme, which would harness electricity from the difference in water levels on either side of a barrage.
In January this year, the Combined Authority revealed that following a detailed analysis of updated Environment Agency flood maps, the project would evolve into a dual infrastructure scheme, providing flood protection against rising sea levels as well as generating clean energy.
A tidal barrage is widely considered to have the potential to play a pivotal role in safeguarding homes, businesses, and critical infrastructure across the region. Councillor Angela Ball, Cabinet Member for Energy and Environment, said: "The Mersey Tidal Power Project is a once-in-a-generation opportunity to deliver clean, affordable energy while protecting our communities and the local environment from the impacts of climate change. It's an iconic solution that will benefit our region for decades to come."
Designated as a Nationally Significant Infrastructure Project under the Planning Act 2008, the Mersey Tidal Power Project is currently progressing through Phase 4 of its development, encompassing environmental assessments, engineering design, and groundwork for a Development Consent Order submission. While the Final Investment Decision is now expected in 2030, the Combined Authority says it continues to work with government and partners to accelerate progress.
