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Published on February 15th, 2014 | by James Ayre


320 MW Swansea Bay Tidal Lagoon Project Moves Closer

February 15th, 2014 by  

The proposed 320 MW, $1.2 billion Swansea Bay Tidal Lagoon project is now one step closer to becoming a reality — developer Tidal Lagoon Power Ltd has now submitted the application for the first phase to the proper development authorities. The project, if approved, will be located off the coast of South Wales and will cover an area of over six miles.

Current plans are for construction to begin in 2015, and for the project to be online by 2018. If Swansea is approved, then it will be followed by four more projects in various lagoons, according to Tidal Lagoon Power — all of which would be completed by 2023, and together (7,300 MW of capacity) provide up to 10% of the UK’s domestic electricity needs.

Image Credit: Swansea Bay via Wikimedia CCImage Credit: Swansea Bay via Wikimedia CC

Given the rejection of the somewhat similar Severn Barrage tidal project just last year, it’ll be interesting to see what happens. That said, nearly the only thing that these two projects have in common is the exploitation of tidal energy — all of the specifics are quite different. In particular, most criticism of the Severn Barrage project came down to the fact that barrages have a significant effect on the environment, whereas tidal lagoons are much less intrusive.

Renewable Energy World explains:

Though the project is still waiting on the environmental go-ahead, experts state that tidal lagoon projects have much less environmental considerations than the heavily criticized Severn Barrage proposal. The 11-mile barrage would have spanned the length of the bay. Barrages allow high tide to flow in, but hold water back until the opportune moment to capture energy as the water recedes. Tidal lagoons take up 40 percent less space than a barrage and allows water currents to flow around the project.

Tidal lagoons are created by building a ring-shaped “sand-core breakwater or rock bund,” which resembles a harbor wall, typically constructed from mainly sand and rock. Turbines mounted in concrete casing are submerged and lined within the wall. When the tide moves in and out, the wall holds water back, and once it reaches a certain level, gates are opened and the water flows through the turbines, which creates electricity.

“This technology will have less impact on fish and other wildlife than the barrage proposals, which conservationists have spent several years fighting in the estuary, and which the government has repeatedly rejected,” stated Sean Christian, special sites spokesman for the bird and wildlife lobby RSPB. “However, it could still have major impacts on the estuary and its wildlife, and we will need to look at the details of each lagoon proposal closely.”

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About the Author

's background is predominantly in geopolitics and history, but he has an obsessive interest in pretty much everything. After an early life spent in the Imperial Free City of Dortmund, James followed the river Ruhr to Cofbuokheim, where he attended the University of Astnide. And where he also briefly considered entering the coal mining business. He currently writes for a living, on a broad variety of subjects, ranging from science, to politics, to military history, to renewable energy. You can follow his work on Google+.

  • jimbo

    I also live in west Wales and think this project will ultimately be a great starting point for a series of Tidal lagoons. I was in support of the Severn barrage but the government didn’t have the guts to press ahead. Ultimately, the pace will be slower at the start. Perhaps Swansea bay will be the first stepping stone to larger lagoons, used for energy storage as well A row of wind turbines on the wall would also be good. .

    • Dave2020

      It’s a misconception that a tidal lagoon can be used for storage. If the potential energy isn’t used, or stored elsewhere, within a single tide cycle, it is LOST.

      The Atlantic Array should be redesigned from the ground up; i.e. NOT using HAWTs, fixed to the sea bed, but with VAWTs, mounted on floating wave energy converters. NO electricity is generated ON these vessels. They all pump water to accumulators, which are shared with tidal installations. Then a great deal less energy storage capacity is required for ALL 3 to deliver dispatchable electricity, and curtailment is all but eliminated.

      I pray that a new government in 2015 will have the intelligence to take charge of rebuilding the UK’s electricity infrastructure so it’s fit for the 21st. century. I am ‘working’ on Peter Hain to try to effect that.

  • Dave2020

    Living a few miles from this project, I have to say my feelings are bordering on despair – that not only does it lack ambition, it is also seriously flawed in its basic design premise, of having 26 turbines driving generators, instead of storing the energy in pressurized accumulators. Dispatchable electricity is a far more valuable renewable resource, given its role in grid balancing.

    If a tidal lagoon rated at 250 MW (check the figures) doesn’t have an environmental impact less than one 32nd that of a barrage rated at 8,000 MW it’s no improvement at all, is it?

    The photo above is of The Mumbles, at the western end. The East side of the Bay (the Port Talbot steelworks) is 11kms away, so a wall of energy storage caissons could enclose an area six times the size – a lost opportunity. The breakwater ring is nearly 10kms long and can’t be linked to nearby wind/wave energy storage.

    Hafren Power propose building their Severn Barrage caissons in new dry docks in Port Talbot, but they’re also working on the false premise of having NO energy storage in their project – crazy! Again, the wrong location has been chosen. A Bristol Channel Barrage from Minehead to Breaksea Point would have a peak capacity of around 15,000 MW and it would be just 20kms long, compared to 18! It would also act as a flood protection barrier for the Somerset Levels – currently inundated by the record rainfall of 2014.

    The description from Renewable Energy World is not correct. The proposed Severn Barrage is a low-head design, generating on ebb and flood, so there is much less disruption of the natural tides. (which need to be controlled in future)

    The Swansea Bay Lagoon could be the perfect ‘first-of-a-kind’ to demonstrate the technology leap of energy storage on BOTH lagoons AND barrages – another tragic missed opportunity.

  • Ross


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