tidal lagoon concept swansea

Cheap electricity from tidal lagoons ‘could power the UK for 120 years’

Tidal lagoons could play a large part in providing the UK with energy in the future, according to former energy minister Charles Hendry.

He recently led a review into the technology, commissioned by the Government, which could support a proposed ‘world first’ project to harness the power of the tides in the Severn Estuary by building a lagoon in Swansea Bay.

The £1.3bn project was originally granted planning permission in 2015 but further discussion was needed with the Government around the level of subsidies it would supply. 

An assessment was commissioned last year amid negotiations on the Swansea Bay project which looked into whether lagoons represent value for money and how they could contribute to the UK’s energy mix in the most effective way.

“We know it absolutely works. One of the great advantages is it is completely predictable for all time to come,” Hendry said.

“We know exactly when the spring tides and neap tides are going to be every single day for the rest of time and so, in terms of meeting security of supply, lagoons can play an important role.”

The lagoon would involve a U-shaped breakwater built out from the coast, with a bank of turbines turned by water which would harness the rise and fall of the tides to generate renewable electricity.

tidal lagoon concept

While the Government has expressed backing for lagoons, former prime minister David Cameron said his enthusiasm had been “reduced” by the costs, with much higher subsidies than nuclear or offshore wind mooted at one stage.

Tidal Lagoon Power now says the Swansea Bay scheme would require only the rate of bill-payer support currently offered to nuclear, and because the project was small it would cost households as little as 20p to 30p on average.

It would also generate thousands of jobs and boost the Welsh economy, while supplying predictable, clean electricity for 155,000 homes for 120 years.

Hendry said he had assessed how expensive the project was by spreading the cost of the subsidies over the lifetime of the project.

“If you look at it over the cost of that 120 years then you get a very much lower figure than almost any other source of power generation,” he said.

Tidal Lagoon Power claims the Swansea Bay scheme would be a proof-of-concept project opening the way for a series of lagoons around the coast, costing less due to economies of scale and meeting 8 per cent of the country’s power needs for 120 years.

Greenpeace UK’s chief scientist Doug Parr said tidal lagoon energy is the most reliable source of renewable energy for the UK and the Swansea Bay project is an opportunity to generate clean power from the tides.

He said: “Up to now, cost has been considered a barrier but the Hendry report suggests that tidal lagoons can potentially play a cost-effective role in the UK energy mix.

“And the Government should get on with it because it could be the first of a wave of tidal lagoons across the UK, and even internationally. So we can lead the world in providing a new, renewable innovation to meet our clean energy needs.

“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 some conservation groups have raised concerns about going ahead with a series of lagoons before the impacts of the Swansea scheme on wildlife are assessed.

Dr Simon Harrison, chair of the IET’s Energy Panel, said: “The recommendation to support the Swansea Bay tidal lagoon is welcome news from an electricity system perspective.  

“Although it may seem relatively expensive at first, it’s important to remember that this is a pathfinder project which, when applied at greater scale in other locations, promises long-term cost-competitive and predictable renewable energy, and a potentially exportable technology.  

“While, there are no major underlying concerns over technical viability there are many issues to explore through Swansea Bay, both technical and environmental, and the learning from this project will be essential in shaping future developments and in determining their viability.

“Tidal energy projects produce predictable electricity outputs every day, but ones that vary with the timing of the tides.   This has the potential to make a valuable contribution to the electricity system as we move more to a smart system where consumers will be able to respond to price signals by adjusting the timing of some of their demand, such as when they charge their electric car

“Tidal lagoons are large and complex construction projects, but if Swansea Bay performs well we might expect to see large scale contributions to the UK’s electricity from tidal sources by the late 2020s or 2030s.”

RenewableUK’s chief executive Hugh McNeal said: “This is a new growth sector with huge potential to bring industrial-scale economic opportunities to the UK. Each new tidal lagoon will drive down costs due to economies of scale, benefitting consumers, as well as strengthening the security of our energy supply.  

“The UK’s future energy mix will be powered by a broad range of low carbon technologies which can be delivered by British companies. This means investing today in new sources for tomorrow – including marine energy technologies such as wave, tidal stream, and tidal lagoons.”

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