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Will the UK have its first tidal lagoon power plant?

Written by Ben Hingley | 19-Feb-2014 16:40:27

Plans for the world's first man-made,  energy-generating lagoon were submitted for planning approval on 7th February 2014.  Swansea Bay Tidal Lagoon would be the largest tidal power plant in the world.  The project would see a 9.5 km long sea wall built to capture enough renewable energy from incoming and outgoing tides to power over 120,000 homes for 120 years.

Mark Shorrock, CEO of Cheltenham-based Tidal Lagoon Power Ltd, the company behind the project, said  “The UK has the second highest tidal range in the world and today we are submitting an application for a development that will prove that this resource can be harnessed in a way that makes economic, environmental and social sense. Tidal lagoons offer renewable energy at nuclear scale and also the investment of hundreds of millions of pounds in UK industries and coastal communities. Our intention is to supply 10% of the UK’s domestic electricity by building at least five full-scale tidal lagoons in UK waters by 2023, before the UK sees any generation from new nuclear.”

The proposal for a tidal lagoon in Swansea Bay would bring energy-generating capacity of 240MW averaging 14 hours of generation every day and clean, reliable and predictable power for over 120,000 homes (enough to power 70% of Swansea Bay's annual domestic electricity use) for 120 years

Consultation with the local community found that 86% of Swansea Bay residents were in favour of the project, which would provide an amenity for the local community and a unique venue for sports, education and arts. The project includes the creation of a 10 kilometre sea reef, the reintroduction of the native oyster into Swansea Bay, an offshore building including visitor and education facilities, and a national triathlon and watersports centre.

The Swansea Bay lagoon would be built as a standard sand-core breakwater or rock bund, similar to many seen in coastal defence schemes and harbour walls.  The generating turbines would be mounted inside concrete housings and be permanently submerged so visually people would see a ring-shaped harbour wall with a section of concrete casing.

As the sea outside the breakwater rises and is held back, a difference in water levels is created, and once a sufficient height is reached sluice gates are opened and water flows into the lagoon through turbines to generate electricity.  This process occurs in reverse on the ebb tide, as sea levels start to fall and a tidal head is created by holding water back within the lagoon. In this way the tides can flow through the turbines four times daily to generate power.  The Severn Estuary holds the second highest tidal range in the world and the developers claim that this tidal range offers significant potential for the extraction of renewable energy.

If given the go-ahead, construction of the Swansea Bay lagoon would begin in the first half of 2015, with first power being generated in 2018.  Surely this is an exciting and bold project that could bring real benefits both financially and socially to the local community and to the UK as a whole.  It is certain that there will be many people who will object to this project but the possible gains must surely mean that the government has to take this project seriously and not dismiss it out of hand just because it is breaking new ground.