Plans to generate electricity from the world's first series of tidal lagoons have been unveiled in the UK.
The six lagoons - four in Wales and one each in Somerset and Cumbria - will capture incoming and outgoing tides behind giant sea walls, and use the weight of the water to power turbines.
A £1bn Swansea scheme, said to be able to produce energy for 155,000 homes, is already in the planning system.
Energy Secretary Ed Davey says he wants to back the project.
The cost of generating power from the Swansea project will be very high, but the firm behind the plan says subsequent lagoons will be able to produce electricity much more cheaply.
It says the series of six lagoons could generate 8% of the UK's electricity for an investment of £12bn.
read more at http://www.bbc.co.uk/news/science-environment-31682529