Do we need a barrage in the Severn estuary?

ANY talk of a Severn barrage involves big numbers: billions of pounds of investment, thousands of jobs, vast quantities of energy.

Hafren Power, a private company, wants to build one.

Company bosses spoke to MPs on the Energy and Climate Change Committee yesterday about their plans.

Last month they submitted written evidence about the 11-mile barrage proposal.

The 42-page dossier said private investors would pay for the £25 billion barrage, creating 50,000 jobs and generating some five per cent of the UK's electricity for at least 120 years.

That is a lot of electricity, the equivalent, said Hafren Power, of three or four nuclear reactors.

This electricity would be predictable and generated (at different rates) for just over 15 hours per day because the 1,026 turbines would spin when the tide comes in as well as goes out.

The barrage could be operational in 2020 and running full tilt five years later.

Complex cost and savings criteria were set out to MPs, which have a large bearing on such a scheme's feasibility and profitability.

Hafren Power said the scheme would require subsidies, financed by all us energy users, for the first 30 years of operation. These would run into several billions of pounds at current levels. After that point, it said the electricity produced would be a quarter of the price of coal, gas or nuclear.

The UK is expected to produce more and more energy from low-carbon sources, and Hafren Power pointed out that its barrage would be "carbon neutral" — measured by the time taken to offset the impact of construction with the clean electricity generated — in just 2.1 years.

Mitigation measures are proposed to offset the project's environmental impact on habitats and wildlife, a major stumbling block flagged up by previous studies. The scheme would have to comply with EU habitat legislation.

But will that be enough for decision-makers back home?

Hafren Power also said the barrage and a tidal lagoon proposed for Swansea Bay "are not mutually exclusive".

Tara Hooper, an environmental economist at Plymouth Marine Laboratory, contributed to evidence given to MPs by the Natural Environment Research Council.

She said the principle environmental issues were habitat loss as a result of raised water levels upstream of the barrage, the spectre of lower water quality due to sewage and agricultural run-off not flushing down the estuary as now, and changes to currents and sediment dynamics.

These issues, she said, were countered by the huge amount of energy and jobs that could be generated.

Could the energy-efficiency measures and (subsidised) solar panel installation advocated in some quarters realistically come close?

"Operating on the flood and ebb tide would mitigate the environmental impacts to some extent," said Mrs Hooper.

"It is difficult to say what the impacts will be. Modelling has been done by the University of Liverpool, but every estuary is different."

Working out the longer-term cost implications was not straightforward, she said.

In her view, it would be useful for such projects to factor in an actual value of the habitats to be lost or adversely affected.

She said a Severn barrage feasibility study was first carried out in the 1920s. Neath MP Peter Hain told his peers last month that the proposal had been "studied to death".

Mrs Hooper said: "As with all these things there are pros and cons. It is a tough decision."

A UK Government spokeswoman told the Post that it was open to "affordable, environmentally responsible projects that represent good value for consumers".

She added: "So far, we have only seen a draft and high-level outline business case from Hafren Power. Even if this proposal can meet our criteria it has a long way to go in development."