Last week’s publication of the National Energy System Operator’s Strategic Case for Tidal Range (2025) marks the first system-level assessment of tidal range energy in nearly a decade.
Its release should be a step forward for the sector, yet many across industry and academia have expressed concern that the modelling is based on narrow assumptions and an outdated system scenario. In particular, it relies exclusively on offshore lagoon typologies and smaller-scale nodes that don’t reflect how large-scale tidal range schemes are now designed, permitted, or financed.
These are legitimate critiques. The report’s approach risks underplaying what decades of evidence from the Severn Estuary, Mersey, and other UK feasibility studies have already demonstrated: that well-sited tidal range projects can deliver predictable, dispatchable power, grid stability, flood protection, habitat creation, and long-term economic benefit – particularly for Wales and the wider west coast.
That said, buried within the caution is something worth noting. NESO’s own analysis found that tidal range can lower wholesale electricity prices, integrate into the grid with minimal curtailment impacts, and that the Regulated Asset Base (RAB) model remains the most promising route to affordability. These findings should not be dismissed – they should be built upon with more realistic assumptions, representative site types, and closer engagement with industry expertise.
Wales’ opportunity in the next chapter
Wales holds two of the most promising tidal range regions in Britain, the Severn Estuary and North Wales coast, and a growing coalition of regional partners ready to take the next step. The question now isn’t whether tidal range fits our energy future, but how to make it deliverable in a way that strengthens both the grid and local economies.
The next phase of work should focus on:
- Collaborative remodelling. A new study co-designed with government, NESO, industry and academia to reflect real-world tidal lagoon and barrage typologies, realistic scales, and electrification-driven demand growth rather than hydrogen-heavy assumptions.
- A Wales-led pathfinder. Building on the work of the Severn Estuary and Mersey programmes, a strategic demonstration project could anchor supply chains, port infrastructure, and a long-term programme of delivery.
- Integrated policy alignment. Consistent treatment of tidal range within DESNZ, The Crown Estate and devolved administrations — recognising it as both an energy and industrial asset.
- Industry partnership. Establishing a dedicated task force to bridge national and regional delivery — turning critique into coordination.
A constructive way forward
It’s right to challenge the limitations of the NESO report. But it’s just as important to ensure the next stage is led from the regions that understand this opportunity best. Wales is ready to play that role, bringing credible evidence, strong partnerships, and a pragmatic vision for turning an untapped national resource into a lasting contribution to net zero, energy security and coastal prosperity.
Marine Energy Wales supports the Tidal Range Alliance’s is recommendations for a National Infrastructure and Service Transformation Authority Task Force to realise the wide-ranging benefits of Tidal Range projects that should be viewed as national infrastructure.