The proposed Severn Barrage could not be built until after 2020 and would cost significantly more than first thought, energy minister Lord Hunt said last week.
Hunt told the energy and climate change select committee of MPs that the scheme was “unlikely” to be built until post-2020.
Five schemes have been shortlisted by the Department of Energy and Climate Change for detailed investigation.
“The scale of the Cardiff-Weston Barrage is huge and would have great implications for grid infrastructure.”
Lord Hunt, energy minister
The schemes under consideration are the 0.625GW barrage at Beachley, costing £2.3bn; the 1.05GW Shoots barrage, costing £3.2bn; a larger 8.64GW Cardiff-Weston barrage, costing £20.9bn; and two 1.36GW lagoon proposals at Bridgewater Bay and Welsh grounds, costing £3.8bn and £4bn respectively.
“You can construct a timetable for one of the smaller schemes so it could be operational by 2020,” he said, although he said that even that would be “difficult”.
Hunt revealed that linking the largest − the Cardiff-Weston Barrage − to the national grid would be an expensive undertaking. “The scale of the Cardiff-Weston Barrage is huge and would have great implications for grid infrastructure. Costs of conversion run to £2bn at least,” he said.
An aide revealed that the £21bn cost of the Cardiff-Weston scheme would “go up” as prices were based on studies from the 1980s and 1990s and did not take account of current Treasury procurement rules.