By Julian Whittle Political editor

Last updated at 11:59, Thursday, 04 February 2010

The Solway Firth has the potential to produce huge amounts of ‘green’ electricity from tidal power, says a newly-published feasibility study.

The study's findings. Click here for larger image

Nine possible schemes are identified, the biggest being an 18-mile barrage from Workington to Abbey Head, near Kirkcudbright, in Scotland.

This would cost £16 billion and have an installed capacity of 5,891 megawatts – 32 times greater than the Robin Rigg offshore windfarm.

The experts say 800 jobs would be created during the construction phase.

As well generating electricity for hundreds of thousands of homes – perhaps enough to meet three per cent of the UK’s needs – the scheme could also be a major tourist pull bringing 200,000 visitors a year.

Less-ambitious options are for three shorter barrages, two lagoons or three tidal reefs.

The study has been carried out by consultants for the Northwest Regional Development Agency, Scottish Enterprise and the Nuclear Decommissioning Authority.

David Gass, regional director of Scottish Enterprise, said: “This study is a milestone in the project, which will allow us to identify how the Solway Firth can help meet targets for renewable energy and carbon reduction.

“The development of the Solway Firth as a source of renewable energy could yield significant economic benefits.”

The study was prompted by Cumbrian businessman Nigel Catterson of the social-enterprise group nb21cand a director of Britain’s Energy Coast. He welcomed the findings.

Mr Catterson said: “We are facing some very difficult choices as far as energy is concerned. This study underlines what we’ve been saying.

“It’s taken four years to get to this stage. It will depend on the scheme, but I believe we could have something in place generating electricity anywhere from 2017 onwards.”

The Solway Firth Energy Feasibility Study has been produced by specialist consultants Halcrow, Mott MacDonald and RSK Group.

It argues that the Solway’s combination of wide tidal ranges and fast-moving water make it ideal for tidal energy.

Electricity connections to the National Grid would have to be upgraded, however.

Tidal power would help the Government to reach European targets for renewable-energy generation.

The study adds that only the larger barrage schemes appear commercially viable.

But it accepts these would do the most harm to the environment. The Solway Firth is an internationally-important habitat for birds.

The study says: “Environmental impact is unavoidable due to the sensitivity of the area. The EU habitat and birds directive will require extensive, appropriate assessment of the impact of the schemes.”

Barrages work by holding back the full height of the tide, creating a sharp difference in water levels on either side.

When the water is released, it passes through turbines generating electricity.

Lagoons work on the same principle but, unlike barrages, do not cross the estuary and so do not block fish migration.

Reefs have a smaller height differential, do not alter tide patterns as much and allow salmon to pass safely.

Mr Catterson is investigating a fourth option – spectral marine energy conversion – which does not affect the flow of the water and would have a minimal impact on habitats.

He said: “Of the established technologies, a reef is better than a barrage from an environmental point of view but doesn’t produce the same amount of energy.

“It’s always been my quest to balance our needs and the needs of nature. We should be able to do that with the technologies available.”

He cites the success of the world’s first tidal power station across the Rance estuary in Brittany, France, which opened in 1966.

He said: “Barrages aren’t as damaging as people think.

“The Rance scheme did devastate the ecology [when it opened] but some would argue that there’s a richer and more diverse ecology now than before the barrage.”

The feasibility study recommends more research is done on costs and energy projections, and on how environmental damage can be minimised.

Mr Catterson will be pressing the Northwest Regional Development Agency, Scottish Enterprise and the Nuclear Decommissioning Authority to fund this work.

Any firm proposals that follow are likely to divide opinion among environmentalists.

Green groups favour renewable energy but oppose any harm to wildlife habitats.

Jill Perry, a former campaigner with Friends of the Earth who is now the Green Party’s prospective parliamentary candidate for Copeland, said: “We favour reefs and lagoons. Barrages are just so intrusive and so damaging to wildlife.

“They damage habitats, very often they don’t live up to promises and can be an excuse to put roads on the top.”

The publication of the feasibility study yesterday coincided with a report from the energy regulator Ofgem warning that Britain faces power shortages in the years ahead.

The schemes

B1: Barrage from Workington to Abbey Head, near Kirkcudbright. Length: 28.4km. Capacity: 5,891MW. Construction cost: £16.0bn. Cost of electricity generated: £184 per MWh. Study verdict: “Largest barrage scheme with greatest energy output and environmental impact. Scale of construction and capital costs are limiting factors.”

B2: Barrage from Beckfoot, near Silloth, to Southerness Point. Length: 11.5km. Capacity: 2,703MW. Construction cost: £6.1bn. Cost of electricity generated: £175 per MWh. Study verdict: “Intermediate barrage, still with substantial environmental impact but offers some compromise.”

B3: Barrage from Bowness-on-Solway to Annan. Length: 1.9 km. Capacity: 316MW. Construction cost: £1.2bn. Cost of electricity generated: £389 per MWh. Study verdict: “Smaller barrage located at narrow section of inner estuary with reduced capital cost and energy output.”

B4: Barrage at MoricambeCORR Bay, near Skinburness. Length: 2.6km. Capacity: 113MW. Construction cost: £640m. Cost of electricity generated: £553 per MWh. Study verdict: “Barrage located out of main estuary to reduce environmental impact. Small impounded area reduces available energy.”

L1: Lagoon Rascarrel to Southerness. Length: 20.5km. Capacity: 692MW. Construction cost: £4.0bn. Cost of electricity generated: £519 per MWh. Study verdict: “Larger lagoon on north side [of the Solway] offering localised environmental impact but higher cost of generation than barrage options.”

L2: Lagoon Maryport to Beckfoot. Length: 19.3km. Capacity: 435MW. Construction cost: £3.3bn. Cost of electricity generated: £639 per MWh. Study verdict: “Southern lagoon with lower energy output of the two [lagoon] options but similar potential environmental benefits.”

R1: Reef Workington to Abbey Head. Length: 28.4km. Capacity: 1,318MW. Construction cost: £12.1bn. Cost of electricity generated: £406 per MWh. Study verdict: “Largest [reef] scheme that enables large scale of generation with lower impact than barrage.”

R2: Reef Beckfoot to Southerness Point. Length: 11.5km. Capacity: 535MW. Construction cost: £7.0bn. Cost of electricity generated: £358 per MWh. Study verdict: “Mid-range reef solution in terms of energy and environmental impact but improved cost of energy due to lower scale.”

R3: Reef Bowness-on-Solway to Annan. Length: 1.9km. Capacity: 88MW. Construction cost: £1.0bn. Cost of electricity generated: £598 per MWh. Study verdict: “Smallest reef where energy generation is limited by reduced tidal range in the shallow estuary. Potential to offer minimal environmental impact.”

First published at 11:23, Thursday, 04 February 2010
Published by http://www.newsandstar.co.uk