The building of a £1bn tidal lagoon in Swansea Bay has been given the go-ahead by the UK government.

Tidal Lagoon Power (TLP) says it will now negotiate how much subsidy will be paid for the energy.

That is still a big hurdle for TLP, which want five other lagoons on the west UK coast to harness power, and needs a guaranteed price for the electricity.

There are also concerns about the impact on the environment and migratory fish.

Environment correspondent Iolo ap Dafydd reports.