Due to the popularity of the single article The Shelf posted on the Hydrogen Age at the beginning of the month, marking the launch of a new eco friendly section, we have brought you news on the latest green projects bidding to harness energy from the Severn estuary in South Wales.
Over the next 24 months ten rivals eco friendly schemes will be studied and narrowed down until one successful renewable energy scheme will be funded, harnessing the natural energy of the Severn.
Among the contenders for the project are six barrages, two lagoon proposals, a tidal fence and a tidal reef.
Environmentalist, bird charities, engineers and opposition politicians have all welcomed to array of projects that will be part of the multi million pound feasibility study, and will each state the proffered scheme.
Business Minister John Hutton spoke of the scheme – “Harnessing the power of the Severn Estuary could be an engineering project of breathtaking scale and we will look at the full range of technologies and locations.”
The ten proposals are as follows:
1. A giant outer barrage that will stretch from Minehead in Devon to Aberthaw in Glamorgen, with critics fearing the projects size could become impractical. That said the project is among the top energy providers and it is estimated it could produce 20 terawatt hours of power annually.
As well as being popular for the amount of energy the project is expected to produce, the project is favoured by conservationists as it would be better than other for bird life as well as protect Somerset from flooding such as that seen across the county in 2007. It is however expected to be an expensive project and could prove difficult to build in such deep waters.
2. The Cardiff Weston Barrage would stretch from Lavernock Point in Sully to Brean Down in Somerset and could cost an estimated £15 billion to build. The project could produce a fifth of Britain’s electricity generating 17 terawatt hours a year and is thus far the best studied option based on proven technology.
The project however is unlikely to gain the support of environmentalists as it is expected to damage rare bird breeding mudflats in the Severn estuary and disrupt shipping in the Bristol Channel.
3. The Cardiff Weston Barrage II would stretch from Lavernock Point in Sully to Hinkley in Somerset costing more than the 15 billion predicted for the first Cardiff Weston Barrage. Avoiding breeding grounds this option may be preferred; however it is based on unproven technology but includes more turbines which would produce more power.
4. The Inner shoots Barrage would be located near the second Severn crossing costing 10% of the Cardiff Weston Barrage at £1.5 billion. It would provide 2.5 terawatt hours of electricity annually, a seventh of the second barrage.
At a cheaper cost to both investors and the environment it may be a popular option, however the energy produced isn’t as clean as that in other proposals.
5. The Beachley Barrage will stretch from Beachley to Aust near the first Severn Bridge and is similar to the inner barrage.
6. The Tidal Fence will stretch from Lavernock Point in Sully to Brean Down in Somerset and cost £3.5 billion, producing 1.3 GW of electricity, 1% of Britain’s needs.
There are questions about the unproven tidal stream power, and critics say it is not ideally suited to the Severn estuary.
7. The Fleming lagoon would be constructed between three sites two up against the Welsh coast, one against the English coast. With an unclear price an estimated 6.5 terawatt hours of electricity would be produced but the scheme is backed by Friends of the Earth who say the scheme is less environmentally destructive.
The drawback to this scheme seems to be the fact it is founded upon as yet unproven technology.
8. Tidal lagoons if chosen could be situated in several places in the Estuary or Swansea Bay, with the cost believed to be comparable to offshore wind power. This option is potentially cheaper and would cause less damage to bird habitats than other schemes.
9. There is a Tidal reef proposal but as yet the details of the scheme are very vague, but it would be based on tidal stream technology that would cause less damage to bird habitats. This scheme doesn’t however take advantage of the massive tidal range of the Severn Estuary.
10. The Severn Lake Scheme would stretch from Lavernock Point in Sully to Brean Down in Somerset at a cost of £650 million. Cheaper that other scheme the Severn Lake Scheme is estimates to generate up to 20% of the UK’s power, but there are doubts about the efficiency of the scheme.