The former UK energy minister Charles Hendry is to publish a report later today (Thursday) backing the development of the Swansea Bay tildal lagoon.
The £1.3bn project would be the first of a sequence of lagoon projects that could ultimately generate around 8 per cent of the UK’s electricity, according to supporters.
Plans for a £1.3bn tidal lagoon in Swansea Bay will be backed in a government-funded review on Thursday.
The UK government still needs to agree on a deal and a marine licence would also need to be approved.
Hendry’s independent inquiry has led to a firm conclusion that the project is feasible and value for money, in terms of a prospective strike price to be agreed with government..
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" include 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 leap tides are going to be every single day for the rest of time."
Swansea Bay would act as a "pathfinder" project, allowing people to learn more about the technology and bring the cost down.
Developers, 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.
BBC reports that the guaranteed price or strike price for the deal could be around £89.90 per megawatt hour.
On price, the firms backing the technology are confident they can force down costs if they get approval for a series of lagoons around the coastline.
Commenting on the publication of the Hendry Review of tidal lagoons, Rémi Gruet, CEO of Ocean Energy Europe, said:
“The UK government has analysed tidal lagoons every which way and the conclusions are unequivocal. Tidal lagoons have a major role to play in providing UK households and businesses with reliable, clean and affordable electricity. It is time to give Swansea Bay the go-ahead and support the development of a new industry with the potential of creating thousands of jobs in the UK and across Europe.”
Ben Warren, Head of Environmental and Energy Finance at EY comments: "Any support for the Swansea Bay tidal lagoon project appears, on the face of it, to be a rare piece of positive news for the UK's renewables sector.
“Whether the UK Government is adopting a strategy of fostering a more sustainable energy industry by supporting local jobs remains to be seen, both by the final decision but, more significantly, by the purchase price the Government will agree to pay for the power produced.
“Currently, truly affordable clean energy from offshore wind and solar is being left to fend for itself while the benefits of subsidy are enjoyed by new nuclear and even fossil fuels.
“Should Swansea Bay get the go ahead it remains to be seen whether tidal energy can deliver affordable electricity in the longer-term. For now we wait to see what price the Government is prepared to pay Swansea Bay for its power, and what risks it is prepared to take on board to ensure this ambitious project gets realised.”