The idea of building a barrage across the River Severn to generate electricity goes back at least to 1925, when an investigation concluded that, although technically possible, the project was too expensive to be viable. It seems little has changed.
The idea has been resurrected many times since then, with three separate studies completed in the 1980s alone. However, the need to avoid climate change and reduce our dependence on oil, by developing clean, renewable forms of energy has in recent years given the idea renewed impetus.
The UK is now committed under EU law to obtaining 15 per cent of its energy from renewable sources by 2020. A barrage across the Severn estuary, which has a tidal rise and fall of 14 meters, could generate 5 per cent of the UK's electricity.
Support for tidal
The Government’s main sustainability watchdog came out in support of the project in 2007 but with a caveat, ecological damage had to be limited. Whether this will be possible is a moot point and part of an ongoing study by the Government. The RSPB is among those who remain strongly opposed.
Following the Sustainable Development Commission’s qualified endorsement, the Labour government launched a fresh feasibility study and shortlisted five different Severn tidal power schemes for further scrutiny.
As recently as last autumn, the then energy minister Lord Hunt told a parliamentary select committee on energy and climate change that the Government would make a decision in 2010.
With Labour’s election defeat in May it appears that impetus may have been lost. The Department for Energy and Climate Change (DECC) confirms that the feasibility study is continuing, but won't say any more than that.
'There is no date for any announcement on what will or won't happen, or for publication of the study, and there is no preference from the Government for any one projects on the shortlist,' says a spokeswoman.
On the face of it, the new coalition Government is an enthusiastic supporter of renewable energy. Last month it promised to push the European Union to move to a higher target for cutting greenhouse gas emissions - urging it to cut emissions by 30 per cent from 1990 levels, rather than the current 20 per cent target, partly through more support for renewable energy.
On the other hand, the Government has no money. Chancellor George Osborne's emergency budget of 22 June indicated that Government departments outside of health and overseas development must cut their spending by 25 per cent over the next four years. Last autumn, Lord Hunt said the most ambitious barrage scheme could cost £21bn.
Critics argue there are better ways to generate clean power. David Newbery, director of the Electricity Policy Research Group at Cambridge University, argues the same amount of electricity could be generated cleanly at two-thirds of the price by building three new nuclear power stations. He says a barrage would be 'ludicrously expensive' and is likely to be shelved.
Subsidy 'cannot be justified'
Newbery says that the whole point of putting public money into renewable energy is to develop new technologies to a level where they become commercially viable and can be deployed all around the world - like for example photovoltaics and concentrated solar power. By contrast, the Severn barrage would use the same hydro power technology as has existed for hundreds of years, so a subsidy cannot be justified.
'It is completely useless for the rest of the world and very expensive for the UK, so it has absolutely nothing going for it,' Newbery declares.
A cash-strapped coalition may well agree. Lord Hunt told a select committee last autumn that the Government had not included the barrage in its plans to achieve 15 per cent renewables by 2020, because the jury was still out on it. He claimed existing policies to encourage wind power and other renewables would be enough to reach the 15 per cent target.
Hunt also said it was possible that the barrage would be shelved and revisited yet again in the coming decades, as the UK wrestles with carbon reduction targets beyond 2020.
With future governments committed to a 80 per cent cut in emissions by 2050, Newbery admits a Severn barrage could eventually make sense, once other options have been exhausted.
'It may be that by the year 2040, there is a [high enough] carbon price that would justify doing it,' he says. 'A Severn barrage may be cheaper than, say, covering the Sahara with concentrated solar power.'
Experts in the financing of renewable energy also have little faith a large barrage will be given the go-ahead in the short-term. 'It might require significant Government support. Given the constrained fiscal environment, that could be hard to secure,' says Ben Caldecott, head of climate change and energy policy at Climate Change Capital, which manages £1bn worth of green investments globally.
Although the Government would seek private money to build the barrage, it would almost certainly have to guarantee a rate of return in order to attract investors. This would mean subsidies and guaranteed prices for the electricity generated.
Meanwhile the energy companies and their bankers are already facing substantial demands on their cash, such as the replacement of existing power stations, investment in renewables, building smart grids and paying towards domestic energy efficiency measures.
Smaller project could go-ahead
Angus McCrone, senior analyst at Bloomberg New Energy Finance, a research company, says the formidable task of devising a funding mechanism for the barrage hasn't even begun. A barrage is also likely to take years to get through the planning system.
'I think the Conservative-led Government will be more sensitive to the planning issues [than Labour was],' he says. 'If something does go ahead, it may only be a smaller version, so it's going to take a long while and in the meantime, the emphasis will be on offshore wind,' McCrone predicts.
Although they have said nothing since forming the coalition Government, the Liberal Democrats have previously backed an alternative smaller barrage, known as the Shoots option because of its location at a fast-running stretch of the river, in 2009. They believed this would be more financially viable and less ecologically damaging, while still providing a significant amount of energy.
Stephen Williams, the Liberal Democrat MP for Bristol West who led the party's own inquiry into Severn tidal power, is still optimistic that a smaller barrage can be built.
'I hope we seize this opportunity,' he says. 'For Liberal Democrats, one of the key tests of this coalition Government will be whether we reduce our carbon footprint. We've got a fixed-term parliament, so we are able to make some far-reaching decisions. We've got to walk the talk.'
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