Controversial plans by the former government to build a massive tidal-power barrage across the Severn estuary have been scrapped. Energy Secretary Chris Huhne, announcing the decision this morning, said the scheme's costs were "excessive".
In theory the door remains open for private business to build a tidal-power scheme of some sort in the Severn, but a project of any size is extremely unlikely as a huge government subsidy would be required to help it to break even.
A range of plans had previously been shortlisted in a government feasibility study, the most ambitious of which would have seen a massive barrage spanning the Bristol Channel from Weston-super-Mare to Cardiff on the Welsh coast. This plan, according to the government's assessment, would produce 17 terawatt-hours each year: about 4.8 per cent of present-day UK electricity demand, or approximately half a per cent of the UK's total energy requirements.
Unfortunately, the cost of such a barrage was estimated at more than £35bn. A modern nuclear powerplant producing the same energy would cost less than £5bn, and thus private sector investors would expect the government to pay most of the costs of building the barrage if they were to make any money selling electricity from it.
Unsurprisingly, given economic developments, the long-running feasibility study has concluded that there is no reason why the government should do this.
"The study clearly shows that there is no strategic case at this time for public funding of a scheme to generate energy in the Severn estuary," said Huhne.
The plans were doubly unlikely to gain approval, as the vociferous Green movement - normally solidly behind any renewable power project - was lukewarm or actively hostile to all the larger plans, which would have seen vast amounts of important bird habitat destroyed.
Shadow Welsh Secretary Peter Hain said the cancellation was "equally disastrous for the Welsh economy and our environment," arguing that a barrage would have "created hundreds of good quality green jobs for Welsh people".
Taken all round, the Severn remains perhaps the best location in the world for tidal power, but the high cost of exploiting it and the unpopularity of doing so seem set to leave its potential untapped for the foreseeable future.