Plans for a £1.3bn tidal lagoon in Swansea Bay have been backed by a government-commissioned review.
Charles Hendry’s independent report into the technology’s viability said it would make a “strong contribution” to the UK’s energy supply.
Henry said it was cost effective and would bring “significant economic opportunity”.
The UK government still needs to agree on a deal and a marine licence would also need to be approved.
Mr Hendry said moving ahead with a pathfinder lagoon off the Swansea coast should be seen as a “no regrets” policy.
There are hopes of developing a network of larger lagoons around the UK coast, harnessing power from the ebb and flow of the sea’s tides.
Former UK energy minister Mr Hendry has been gathering evidence for nearly a year for his independent inquiry, including visits to all the potential sites and discussions with industry.
Mr Hendry said: “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.
“That’s where I think we can start a new industry and we can do it at an affordable cost to consumers.”
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.
Some parties have voiced concerns over wildlife, fishing capabilities and how cost effective the lagoons can become however the use of established technologies along with the economies of scale in building further lagoons across the UK will make the schemes a cheap source of clean Energy.
This economies of scale argument is central to one of the key questions over the so-called “strike price” – how much the UK government is prepared to pay for the energy the lagoons will generate.
But there are still environmental concerns and Natural Resources Wales (NRW) will be looking at the impact on flooding, fish, birds and marine habitats before it awards the all-important marine licence.
Gloucester-based TLP’s contention is that the Swansea project will be a test bed. But the technology 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.