Location: Severn Estuary, spanning from Lavernock Point in Wales, to Brean Down in England.
Length: Approximately 10 miles.
Lifetime: 120 years minimum.
CO2 savings: 7.2 megatons per year (7200000 tons)
Percentage of total UK electricity supply: Approximately 4.8%
Habitat Loss: 10000ha
Data taken from the Consultation Summary of the Severn Tidal Power Feasibility Study Consultation, available here, from the UK Department of Energy and Climate Change.
The Severn Barrage would, on this scale, be a line from Cardiff to Weston-super-mare, a distance of approximately 10 miles.
Why build the Severn Barrage?
Quoted from a report by The Independent, a leading UK daily newspaper:
...in December ministers took on the enormous obligation, in an EU-wide deal, of sourcing 20 per cent of total UK energy demand from renewables by 2020.
The Severn Barrage would account for about 5% of this target, more than all other UK renewable sources combined.
It would take about 6 years to build (from 2010, if it is given the go ahead) and would be a major step forward in helping the UK meet its targets.
The Independent also claims that it would be the largest renewables project in the world.
Why in the Severn Estuary
The Severn Bridge, across the Severn Estuary. Photo courtesy of Amy Taylor.
It seems that the river Severn has the second largest tidal range in the world (14m/45ft).
At spring tide, "450 million litres a second pass through the Estuary" [The Rt. Hon Ed Miliband, Secretary of State for Energy and Climate Change]
If the UK were to take hydroelectric power seriously, the Severn Estuary would have to be used somehow.
Though the Severn Barrage isn't the only possible option, is it by far the largest, most ambitious, and would generate the most energy of all other possibilities.
There is, however, a problem...
Environmental impacts of the Severn Barrage
The region behind where the dam would be contains a large area of habitat for various bird species. The presence of the dam would also affect fish life in the river.
The problem environmentalists (a group of which I do not claim to be a part) face is that though they support the expansion of renewable energy in the UK, they are unhappy with the devastation the presence of this dam would cause.
The copy of The Independent sitting here next to me tells me that species affected will include salmon, dunlin, baby eels, redshank and shelduck.
I admit, I've never heard of many of these before, though I have probably eaten some. The question of whether we have a right to damage the immediate environment to better the global one is an interesting question.
Do we sacrifice a few birds and fish for the sake of that 5%? Perhaps "a few birds and fish" is unfairly underestimating the scale of devastation that will be caused?
The Severn Barrage is the most massive of several options put forward in proposals of how to harness energy from the Severn Estuary. Others include forming bays, damming different sections of the estuary, and using different technologies.
Without overloading you with detail, I'll just say that every one is smaller, would damage the immediate environment less, but would produce significantly less energy.
The question is, if we're going to build such things out there, why not make the most of such a great natural resource? Can we find a way to protect the local habitats whilst still going ahead with the barrage proposal?
I'd welcome your thoughts and comments regarding whether this project should go ahead, so please do contact me with your thoughts.
Personally, I'd be happy for this project to go ahead if more thought is given to the mitigation of local wildlife, but otherwise, the idea is an excellent one.