Multi-Billion Pound Mersey Tidal Barrage Pitched as 120-Year UK First

Multi-Billion Pound Mersey Tidal Barrage Pitched as 120-Year UK First

If given the green light, a proposed tidal barrage across the River Mersey could become the largest infrastructure project in the North West.

The Liverpool City Region Combined Authority (LCRCA) has proposed a £multi-billion barrage designed to generate predictable renewable energy for over a century while better connecting Liverpool and Wirral.

The project proposal outlines the scale, technology, and significance of what would be the first tidal barrage in the UK. The barrage aims to contribute 700MW capacity to the region’s renewable energy mix – enough to power up to 1 million homes. It would achieve this by utilizing 28 tidal range turbines, each generating 25MW, supplemented by sluice gates for water flow management.

The LCRCA report compares the proposal to the La Rance tidal plant in France and the Sihwa facility in South Korea. At 750m long, La Rance has 24 x 10MW turbines and has been operating since 1966. Sihwa stretches 12km and has 10 x 24.5MW turbines that came online in 2014. The Mersey project would eclipse both in scale and capacity.

However, critics have questioned the environmental impact, economic feasibility, and engineering complexity. The barrage could impede shipping lanes along the Mersey and lead to silting that affects wildlife habitats. The multi-billion pound price tag also requires substantial government backing amid a cost-of-living crisis. A barrage of this magnitude has never been built in the turbulent Mersey estuary.

The LCRCA seems committed to the project as a critical pillar of regional decarbonization efforts. The authority envisions delivery by 2040, with operations lasting at least 120 years alongside new offshore wind farms expected by 2030. Realizing the plan requires national policy support for tidal range technology, dedicated public funding, updated regulatory frameworks, and cooperation with project partners like Korea’s K-Water.

Multi-Billion Pound Mersey Tidal Barrage Pitched as 120-Year UK First

The Liverpool City Region Combined Authority (LCRCA) has unveiled ambitious plans to construct a tidal power barrage across the River Mersey. The proposed project would link Liverpool and the Wirral through a monumental feat of engineering designed to harness the Mersey’s immense tidal range.

Billed by LCRCA as the largest infrastructure project in the North West, the £multi-billion Mersey barrage could provide predictable renewable energy to power up to one million homes for over a century when completed. The project’s scale and operating lifespan would make it a UK-first and bold statement of intent to combat climate change.

Liverpool City Region Combined Authority’s Proposal

The outlined Mersey Tidal Power barrage plans involve installing 28 tidal turbines, each generating 25 megawatts, alongside marine navigation locks and sluice gates within a constructed barrage across the Mersey.

With Mersey’s tidal range reaching up to 10 metres, the 680-megawatt tidal plant could generate over 500 gigawatt hours per year once operational. For context, this approaches the productivity of France’s famous La Rance tidal barrage.

The proposal claims to produce such reliable green energy near urban demand centres directly tackles issues with transmission constraints and intermittency facing expanding offshore wind. Tidal power’s predictability also buffers against reliance on imported fossil fuels.

Challenges and Critiques

Beyond aspirational computer-rendered imagery, delivering this vision requires confronting immense financial, environmental, and engineering challenges.

Constructing such a large-scale barrage could incur multi-billion pounds of costs and complex marine operations, necessitating substantial government backing. Optimistic projections promised from conceptual m

Major infrastructure projects also frequently need to materialize.

The project’s supporters must further assess and mitigate the sweeping ecological impacts of altering tidal flows in a significant estuary. The feasibility hinges on effectively balancing clean energy production with preserving fragile, threatened habitats. Careful environmental impact management prevented the cancelled Cardiff tidal lagoon from suffering Swansea’s fate.

While the Severn Estuary’s extraordinary tidal range inspires adventurous engineered solutions, attempting to tame natural forces on this scale cedes little margin for error. Supporters highlight tried and tested tidal barrage examples, yet previous multi-billion pound UK tidal proposals notoriously struggled to transition from alluring imaginary to physical reality.

Realizing the project’s ambition would require central government enthusiasm, financial support, and regulatory amendments. The project can only advance by securing planning approval and key project enablers.

LCRCA stressed the need for unambiguous government tidal range backing in energy policy and streamlined planning frameworks. Direct development funding and incentives must also improve offshore wind support. Collaborating with regulators and private partners will further de-risk the formidable undertaking.

If getting past these challenges proves successful, the authority anticipates being operational by 2040 alongside recently approved expansions of Liverpool Bay’s burgeoning offshore wind capacity. The project would then provide locally produced renewable electricity to the region for over 120 years.

The proposed Mersey barrage scheme’s scale and engineering ingenuity reflect tidal power’s enormous untapped UK potential. Supporters portray the concept as vital to fortifying national energy security and catalyzing a new renewable industry that is exportable worldwide.

Still, realizing a mega-infrastructure project defying complex maritime conditions requires reconciling towering costs and risks. Structural lifespan carries little value if financial and political inertia leaves blueprints confined to glossy pamphlets. Transitioning Liverpool’s defining waterfront from imagery into a UK tidal power trailblazer constitutes the next incredible regional engineering feat.


  • Liverpool City Region Combined Authority proposes £multi-billion Mersey tidal barrage project
  • The planned 28-turbine, 700MW barrage would power 1 million homes for 120+ years
  • Project hailed as UK’s first and vital for energy security and emissions reduction
  • Critics question the feasibility and environmental impact of large-scale estuary project
  • Success requires substantial government support and private investment
Born to Engineer Weekly

Get the latest Engineering news delivered to your inbox every Monday morning