Swansea Bay £850m tidal lagoon plan submitted
Plans have been submitted for a £850m tidal lagoon in Swansea Bay which could provide power for 120,000 homes over 120 years.
Tidal Lagoon Swansea Bay Ltd says it is the first step towards developing technology that could meet 10% of the UK's electricity needs from the tides.
The six-mile-long U-shaped seawall will go from Swansea docks to near Swansea University's new Fabian Way campus.
It would take two years to build and create 1,850 construction jobs.
BBC Wales environment correspondent Iolo ap Dafydd reports.