A long-awaited official report on the network impacts of delivering Tidal Range energy is based on “flawed assumptions and outdated modelling”, according to the Tidal Range Alliance (TRA) which believes the globally tried and tested technology must be part of the UK’s future energy mix.
The (TRA) has issued a highly critical response to the National Energy System Operator (NESO) and Arup’s report today warning that its conclusions fall short.
Kate Gilmartin, CEO of the British Hydropower Association which co-ordinates the TRA (pictured above) , said: “This report is based on flawed assumptions and should be urgently rescoped with industry and academia.”
Unlike Arup’s earlier study for the Severn Estuary Commission, which confirmed the technical and economic viability of Tidal Range schemes, the NESO analysis overlooks decades of evidence.
The Severn report identified optimal tidal sites that balance high energy yield with environmental protection, found over 60% potential UK supply-chain content, and highlighted wider benefits including flood defence, habitat creation, regional regeneration, and predictable, dispatchable power that strengthens the grid and complements wind and solar.
The reports errors/omissions include:
- Using offshore lagoons rather than real-world land-connected lagoons or barrages.
- Modelling of only 700 MW node, far smaller than realistic large-scale schemes (2–3 GW)
- Focussing on the Hydrogen Evolution Pathway within NESO’s Future Energy Scenarios (FES) uses pessimistic hydrogen-dominant scenarios instead of electrification, which is not representative of net-zero policy direction.
However, one key finding in the NESO report is that Tidal Range can lower wholesale energy prices, although this is stated as having the perverse impact of pushing up the subsidy costs under the Contracts for Difference scheme, this neglects the multiple variables of the future grid composition, storage and flexibility.
The report also suggests that there needs to be further research and that the RAB is the most cost-effective way to deliver Tidal Range.
Gilmartin adds:“Unfortunately, the biggest barrier to Tidal Range is getting the Department for Energy Security and Net Zero (DESNZ) to give Tidal Range thoughtful evaluation, based on the body of knowledge built up through the Severn Estuary Commission, the Mersey tidal project and the Welsh Tidal Lagoon challenge.
“While the regions spend time, resources and money to evaluate the value of Tidal Range to their local economies, building on the expectation from the Devolution Bill that Mayors and devolved Governments can be masters of their own destinies – DESNZ is not matching this motivation with credible policy conversations steeped in well researched and accurate reports. The regions see Tidal Range as a key factor to growing an industrial strategy, jobs and skills not just an energy asset.
“As an island nation, with a large and untapped strategic resource that could bring forward assets lasting over 120 years offering timetabled generation, next to population centres that will consume this volume of energy, this cannot be kicked down the road again.”
The TRA points out that the UK needs to develop a diverse mix of energy infrastructure that will provide grid resilience for generations to come.
The TRA has urged the Government to bring industry and stakeholders together in a Tidal Range task force, that builds on the work of the Severn Estuary commission and does not rely on flawed and outdated studies.