The idea of an electricity generating tidal barrage across the Severn Estuary between England and Wales has been around for 160 years. Conceptually the Severn tidal barrage is a simple and green renewable energy technology in a location which has the second highest tidal range in the world (next to the bay of Fundy in Canada).
The Severn Barrage has had numerous advocates from James Lovelock and Tony Blair to the Welsh Assembly. Why is it then that every time the idea is resurrected by a new advocate it rapidly disappears from the headlines to sink back into the mudflats?
The Severn Barrage between Weston in the west of England and Cardiff in Wales would comprise of an impoundment type of structure with over 200 turbines. Professor Roger Falconer at the Water Management School of Engineering, University of Cardiff estimates that the barrage would generate around 8.6 Gigawatts of electricity at peak times and 17 TWh per year. This would provide for the electricity needs of roughly 5% of the UK population. Aside from the benefits of generating clean electricity, the barrage would also potentially reduce flood risk and reduce effluent levels.
Many organisations however bitterly oppose the project including the Royal Society for the Protection of Birds due to the lost inter-tidal mud flat habitat which is important for birds.
The UK independent Sustainable Development Commission (SDC) believe that if the barrage is to be built it should be environmentally sustainable. In order to be sustainable it must:
• be publicly led as a project and publicly owned as an asset to avoid short-termist decisions and ensure the long-term public interest
• fully comply with European Directives on habitats and birds i.e. involve the creation of compensatory habitats on an unprecedented scale
The costs of the project both with and without habitat creation are high. Estimates for building the barrage are in the region of £21 billion ($32 billion US) according to government advisers. Furthermore there would be a huge cost in finding and funding land and the creation of over 7,000 hectares of inter-tidal mudflats which would need to be provided in order to compensate for the lost bird habitat.
The SDC believe that further investigations into the environmental opportunity that might exist for combining climate change mitigation with adaptation through a habitat creation package that actively responds to the impacts of climate change over the long term should be carried out.
In January of this year 5 tidal barrage and lagoon projects for the UK Severn Estuary were chosen for a government shortlist including the long – time promoted Cardiff to Weston barrage. A consultation exercise on these proposals closed at the end of April and a second public consultation is to be held (probably in 2010), once the government has all the detailed information on the costs, benefits and impacts of the final short-listed schemes. This will also be before any decision is made by Government on whether to support a Severn tidal power scheme, and if so which one.
It therefore appears that unless land can be found for mudflat creation together with a spare $21 billion of public money, the Severn Barrage will continue to be a re-occurring “brilliant conceptual idea”.
Rupert Armstrong Evans
June 4th, 2009
Why when anyone talkes about using the power of the tide in the Severn Estuary do they always concentrate on the most controversial and environmentally damaging option, the Cardiff-Weston Barrage. There are other projects including mine, the ‘Severn Tidal Reef’ that could not only generate as much or more power but also has the support of all the main environmental groups lead by the R.S.P.B.
Isn’t it time we took a more mature attitude and cooperated to make this project work?
Vicky Portwain
June 4th, 2009
Hi Rupert
Check out the following post which does briefly mention the alternatives…
http://www.windenergyplanning.com/tidal-power-one-step-further-to-reality-in-the-uk/
How much energy is your alternative set to generate?
Vicky
Terry Portwain
June 11th, 2009
This may sound flippant, but I feel its valid: perhaps someone should point out to the RSPB that unless we embrace energy sources akin to the Severn Barrage, those mudflats that they are so keen to preserve will disappear under rising sea levels in the not to distant future.
Martin Gardner
June 16th, 2009
Terry, your point is a reasonable one, but essentially what you advocate is that the mud flats are going to be destryoed if we do nothing, therefore we may as well destroy them now to try to prevent them from being destroyed. This argument doesn’t really stack up when you consider that there are potentially other ways in which we could reduce our carbon emmissions sufficiently whilst also leaving the mud flats intact.
As for the original question, it seems to me that the answer is probably to do with political will. The energy utilities are unlikely to devote such massive funds individually or as a JV to a project which is guaranteed to attract controversy and environmental protests and any political party will be exactly the same – they will not want to become too closely associated with such a political hot potato. The public perception is not of Rupert’s more environmentally sensitive proposal, but of the much more damaging Cardiff-Weston proposal, and it will take a massive PR campaign to convince voters that an efficient project which doesn’t do too much damage to the environment can be achieved.
Bryn Howells
January 7th, 2010
How many hours per day would the barrage turbines produce electricity? Would the barrage reduce the need for power stations to generate the base load? How can the high cost of construction be justified?
wind
January 8th, 2010
I understand that the barrage would generate on the ebb-tide, operating about 5 hrs out of the 12.5 hr cycle, but using pumps to store water for peak energy demand times. The important thing is that it would offset burning coal and gas in power stations. I have not looked at the detailed figures but I’d hazard a guess that it is no more expensive that nuclear (including decommissioning)