A Severn Barrage between Weston-super-Mare and Cardiff would only need Government subsidies at the kind of level paid out to nuclear power, rather than more expensive energy like wind power.
Gregory Shenkman, the chairman of Hafren Power, told a parliamentary energy select committee yesterday, that the £25 billion barrage project was economically viable and would not create a hugely expensive form of renewable power.
Experts clashed over whether such a barrage would increase the risk of storm surge flooding 'downstream' of the barrier – on the Somerset Levels with the Environment Agency saying more work was needed to assess that possibility.
The 11-mile long barrage would effectively dam up the Severn Estuary and protect the Somerset and south Gloucestershire coastline to the north from any potentially damaging tidal or storm surges.
But the Environment Agency's submission to the Commons committee remained non-committal, acknowledging that the impact on flood risk was probably 'neutral' – while it decreased the risk and added protection 'inside' the barrier, it could increase the risk of sea flooding further along the coast in west Somerset and north Devon.
The Environment Agency has sought to counter claims that a barrage would help flood risks in Somerset, only telling the Government: "Further work is required to understand the effects on coastal regions far from the Severn."
That implies that as a storm surge hits the barrage and cannot proceed further, it will 'spill over' onto areas outside the barrage.
But hydroelectric power expert, Professor Roger Falconer from Cardiff University, said the detrimental effects downstream would be marginal. "The savings upstream will far outweigh the marginal flood risk downstream," he said.
While the environmental impact is yet to be resolved, the boss of Hafren was upbeat about the costs of the electricity the barrage would produce. All electricity has to be subsidised by the Government to produce it – but the barrage power would not be as expensive as previous fears, Mr Shenkman told MPs.
"We expect that the price we will be able to negotiate will fall below offshore wind, and we hope close to or perhaps at the price nuclear power is currently negotiating," he said. That would make the project economically viable, he added.
Hafren's plans would see 1,026 turbines generating power on tides as the sea rises and falls. The project may create about 20,000 construction jobs and 30,000 manufacturing and service jobs. Finance would come from private sources.