Tidal range technology harnesses the natural rise and fall of the tide to generate electricity. It typically uses a lagoon or barrage to capture and release water, and offers a predictable and long-term energy resource. Wales is home to two of Britain's most promising tidal range opportunities in Britain; the Severn Estuary and the North Wales Coast.
Both regions offer exceptional tidal resource, alongside a strong network of supportive local authorities, industry, academia and development organisations. Yet whilst tidal stream technology is progressing towards commercial deployment, tidal range in Wales is still laying its foundations.
The technology offers enormous long-term opportunity. It is proven to be able to lower wholesale electricity prices, integrate into the grid with minimal impact, and critically, deliver predictable power.
In 2025, The National Energy System's Operator (NESO) published its first system-level assessment of tidal range technology in almost a decade. It confirmed what years of feasibility studies across the Severn Estuary, Mersey, and other UK sites have already demonstrated; well-sited tidal range projects can deliver not only energy but grid stability, flood protection, habitat creation and long-term economic benefits.
Their report marked a turning point for the sector but also exposed a critical gap between how tidal range projects are modelled at a national level, and how they are designed, permitted, and financed by developers on the ground.
Delivering tidal range
The evidence for harnessing the Severn Estuary's tidal range has been extensively examined by The Severn Estuary Commission. After a year of engagement with more than 500 people across over 200 organisations, it concluded that developing the technology in the Severn Estuary is feasible.
The Commission judged that whilst a large barrage should not be pursued at this stage, the development of a commercially viable lagoon, which could become the world's first, would generate substantial low-carbon electricity and provide a platform to fully evaluate the environmental impact of a full-scale project.
The Commission has since laid out several recommendations. They include aligning UK and Welsh Government policy, including tidal range in NESO's Strategic Spatial Energy Plan, and a Wales-led demonstration project, co-designed by engineers and environmentalists.
Crucially, The Commission calls for tidal range to be assessed on the same evidence-based terms as other major infrastructure, albeit with a different financing model.
Tidal range projects are massive infrastructure schemes, requiring enormous upfront capital expenditure. Their operational lifespans are measured in decades or centuries, and they could deliver returns for generations.
It means that conventional project finance models are not necessarily an appropriate route. NESO's modelling identified the Regulated Asset Base (RAB) model as the most promising route to affordability for tidal range schemes in the UK. It is how water, gas, electricity networks and roads are currently financed.
turning readiness into delivery
The foundations to deliver tidal range in Wales are firmly in place - world-class resource, decades of feasibility evidence, established partnerships ready to act, and a national assessment that confirms the technology's longterm potential.
The next chapter now hinges on turning readiness into delivery. It means aligning policy and financing frameworks, grounding planning in real-world experience, and supporting a pioneering Welsh project that can demonstrate delivery at scale.
Together, these steps could move tidal range from promise to practice and help shape a more resilient future for Wales' marine energy sector.
This article originally appeared in Marine Energy Wales' State of the Sector 2026 Report.
