Tidal lagoons : a more eco-friendly form of hydro-power

Plans for a £1.3bn tidal lagoon in Swansea Bay will be backed in a government-commissioned review. The Swansea Bay project would involve 16 turbines along a breakwater but is seen as only the start - a prototype for much larger lagoons. The "fleet" includes one off the coast of Cardiff - east of where Cardiff Bay is now - Newport, Bridgwater Bay in Somerset, Colwyn Bay and west Cumbria, north of Workington.

Speaking on BBC Radio 4's Today programme, Mr Hendry said the lagoon would be a "world first" which was different to barrages elsewhere in the world as lagoons do not block the mouth of a river. "We know it absolutely works," he said. "One of the great advantages is it completely predictable for all time to come - we know exactly when the spring tides and neap tides are going to be every single day for the rest of time."

He said the best way to look at the cost was the subsidy required by the taxpayer over the lifetime of the project. This calculation gave "a very much lower figure than almost any source of power generation," he insisted. "If you look at the cost spread out over the entire lifetime - 120 years for the project - it comes out at about 30p per household for the next 30 years. That's less than a pint of milk."

Swansea Bay would act as a "pathfinder" project, allowing people to learn more about the technology and bring the cost down.

Tidal Lagoon Power (TLP) claims the Cardiff lagoon is being designed to generate enough electricity for all homes in Wales and that it would be the cheapest electricity of all the new power stations in the UK. Gloucester-based TLP's contention is that the Swansea project will test the technology but it will come into its own - and could eventually meet 8% of the UK's energy needs - when the network of more cost-effective, larger lagoons come on stream over the next 10 years.
http://www.bbc.com/news/uk-wales-38571240