Making the most of this reliable source of energy will require long-term investment, the ICE’s Autumn Prestige Debate hears.
Tidal range power could contribute significantly to the UK’s energy mix – if decision-makers had the vision to commit to big investments with long payback periods.
That was one of the key messages from experts in the field who spoke at the ICE’s recent Autumn Prestige Debate.
While they acknowledged that the initial cost is relatively high, they argued this should be set against the potential service life of a power station.
“This is going to last longer than a lifetime,” said Dr Andrew Garrad, chair of the Severn Estuary Commission, who presented on the proposed tidal scheme for the estuary.
“We should be expecting at least 120 years,” he added.
He suggested that the UK’s reluctance to embrace tidal range power might stem from the idea that “we’re simply not used to dealing with something that lasts so long”.
Garrad noted that tidal range tech is well established, so it has a long-term record of success that few other renewable generation systems can match.
Despite this, there is “political tension” among policy-makers about which ones to use to achieve the nation’s net zero goals, with some favouring less proven technologies, he said.
Garrad shared that the plan to create a tidal lagoon on the Severn Estuary could realistically meet 5% of the nation’s existing electricity demand.
He added that the scheme wouldn’t span the whole of the River Severn to minimise negative effects on shipping and the environment.
Dr Shaun Benzon, head of tidal project development at the Liverpool City Region Combined Authority, presented on the proposed tidal barrage on the River Mersey.
Opting for a barrage would take advantage of the narrowing of the estuary between Liverpool and Birkenhead on the opposite bank. This project featured prominently in the ICE’s 2025 State of the Nation report.
Both speakers set out the potential benefits of tidal range schemes.
Aside from providing predictable supplies of low-carbon electricity for many decades, they can offer flood protection, improve transport links and even become an accessible local attraction.
The Mersey barrage could provide a new river crossing for pedestrians and cyclists, for instance.
“That placemaking opportunity is unique when you consider this against other energy infrastructure schemes,” Benzon argued.
“Normally, electricity generation projects are hidden away from communities because they’re not really attractive and things you can interact with.”
The debate, chaired by the ICE’s Senior Vice President, David Porter, featured contributions from four other experts.
They were:
The panellists acknowledged the high upfront cost of tidal range projects as a key deterrent to financial decision-makers.
They agreed that financial assessments should take a longer-term view of such schemes rather than using discounted cash flow models that typically gauge returns on investment over 30 to 40 years.
The regulated asset base model, which has been used on the Thames Tideway Tunnel and Sizewell C nuclear plant, was suggested as a suitable viability assessment tool.
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