Tidal lagoons would deliver energy security, decarbonisation of electricity generation and jobs, and could enable the UK to become a world leader in the technology, a government-commissioned review has concluded.
The review, by former energy minister Charles Hendry, was commissioned in February 2016 by David Cameron, after the then prime minister raised concerns over the estimated £1bn cost of a proposed tidal lagoon project for Swansea Bay.
Ed Davey, who championed the project during his time as secretary of state for energy, revealed that tidal lagoons had been opposed both by the civil service and Conservative MPs at that time.
The review concluded that a project under 500MW would increase household energy bills by around 30p a year over the first 30 years of its lifetime, while a larger scheme would raise them by less than 50p a year over 60 years.
‘Tidal lagoons can be an important and exciting new industry for the UK. We are blessed with some of the best resources in the world, which puts us in a unique position to be world leaders,’ Hendry said.
He urged the government to ‘seize the opportunity to move this technology forward now.’ It should establish a similar strategy to that for offshore wind, with a ‘clear sense of purpose and mission’, to enable the development of a whole industry, rather than a small niche, he said.
Hendry recommended that the first tidal project be operational for a ‘reasonable period’, so that the full impact of such projects can be understood, before a decision to build larger-scale systems is taken.
Developer Tidal Lagoon Power secured development consent for the Swansea Bay project in 2015 . It claims that the 320MW project would generate enough power to meet the annual needs of 155,000 homes and create more than 2,000 jobs in construction and manufacturing alone.
The project involves the construction of a six-mile wall around Swansea Bay in South Wales, creating a lagoon in the Severn Estuary. A bank of 16 turbines under the wall will generate energy four times a day, from outgoing and incoming tides.
Hendry’s report was welcomed by engineering and industrial organisations. Jenifer Baxter, head of energy and environment at the Institution of Mechanical Engineers, said: ‘The support of the Swansea tidal scheme could create new opportunities for turbine, efficiency and design innovations as well as connecting this power source to storage solutions, such as cryogenic or new localised transport infrastructure.’
Simon Harrison, chair of the Institution of Engineering and Technology’s energy panel, said that ongoing reductions in the cost of energy storage would facilitate tidal energy, given the predictability of its output.
Director of UK Steel, Gareth Stace, said that the report was right to highlight the boost tidal lagoons would provide for the steel industry. ‘If a project goes ahead in Swansea, the government must ensure that maximum use can be made from locally manufactured steel to ensure not just ‘jobs being created’, but ‘jobs saved for the long-term’.’
Campaign groups are also largely supportive of tidal power. Greenpeace UK's chief scientist, Dr Doug Parr, said: ‘If Swansea is successful it could prove the investment case for further major projects that could potentially generate a significant chunk of the UK's electricity needs, and help towards meeting our carbon targets, whilst creating thousands of new infrastructure jobs too.’
But Friends of the Earth and the Wildlife Trusts stressed the importance of properly assessing potential impacts on wildlife and the wider environment before any new developments are given the go-ahead.
The Hendry review states that tidal lagoons are a largely untested technology and, as such, it could not provide factual assessment of full lifecycle environmental consequences for the Swansea project. It also says that, in many cases, compensatory habitat for wildlife would need to be provided by developers. A separate tidal lagoon proposed for Cardiff Bay would require a ‘very significant amount’ of compensatory habitat, it said.
According to the Wildlife Trusts, the mudflats of the Severn Estuary are home to around 75,000 migratory birds.
The Swansea project must now apply for a marine licence from Natural Resources Wales, as well as financial subsidy under the Contracts for Difference scheme. Companies working with Tidal Lagoon Power on the project include Atkins, General Electric and Laing O’Rourke.
