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”.

The Carbon Trust told us several years ago that 20% of UK’s current electricity demands could be met by wave and tidal energy. The Ocean Renewable Energy Coalition says 252 million megawatt hours a year could be generated off the coast of the US and the World Energy Council has said 1 million gigawatt hours of wave energy hits Australian shores annually.

Huge efforts are being made to tap into energy from moving water and investors are starting to take an interest. The International Wave Energy Summit is to hold a Dragon’s Den for wave energy technologies in London this year. The summit to be held on the 30th June and 1st July is offering a chance for companies to pitch their wave business to potential financial investors.

The Dragons are described by organisers “Wave Energy Today” as having “a wealth of experience and expertise in backing energy projects which you can leverage to build a great business plan“. Each contender has 5 minutes to present their wave business demonstrating technical ability and future plans to the panel of Dragons. First hand feedback is then to be given by the Wave Dragons.

In the UK to date marine technology R&D has been funded by government subsidised body The Carbon Trust. The Trust set up the Marine Energy Accelerator funding program to dish out £3.5 million over a period between 2007 and 2010. To date around half of this has been spent on wave energy Anaconda and tidal stream generator Deep Green.

Many involved in the marine industry point to cost being the current major problem with harsh sea conditions requiring tough technology and giving further problems relating to installation.

At a previous meeting with 25x’25 America’s Energy Future – a group seeking to reduce America’s carbon emissions – he said “More than three-fourths of the nation’s electricity demand comes from coastal states and the wind potential off the coasts of the lower 48 states actually exceeds our entire US electricity demand“.

Salazar’s comments follow the publication of a report by the U.S. Minerals Management Services (MMS) and the US Geological Survey about data available to investigate the potential of the outer continental shelf (OCS) for new conventional and renewable offshore energy resources. The next stage is to carry out regional public comment meetings around the country over the next few weeks in Atlantic City, New Jersey, and New Orleans, Louisiana.

Salazar said “The purpose of these meetings is to have an open, honest conversation with the American people to solicit the best information possible about an offshore energy plan…the Department’s efforts over the next six months to develop a comprehensive offshore energy plan will embrace the President’s commitment to a government that is open and inclusive and that makes decisions based on sound science and the public interest.”

Private citizens, governors and elected federal officials, interested organizations and entities, energy producers, advocacy groups, Alaska Natives and tribal organizations, science and research groups, and state and local governments are invited to attend and offer brief comments or ask questions.

The MMS has the lead role of developing wind energy on the OCS – leasing, exploration, development, production, and decommissioning. The report states that offshore winds are frequently located near high- energy demand centers – with 28 of the 48 contiguous States having a coastal boundary, including the Great Lakes. Electric-use data show that these coastal States use 78 percent of the Nation’s electricity. The executive summary confirms that developing wind energy in shallow waters of up to 30 metres could provide at least 20 percent of the electricity needs of almost all coastal states. The report also recognises the longer term potential of wave and tidal energy.

The huge 10 mile long Cardiff Weston Barrage proposal from Weston Super Mare to Cardiff could generate as much as 5% of UK electricity requirements, whereas the smaller Bridgwater Bay Lagoon project between Hinkley Point and Weston Super Mare has the potential to generate just under 1%.

Energy and Climate Change Secretary Ed Milliband said “The Severn Estuary has massive potential to help achieve our climate change and renewable energy targets…the five schemes on the shortlist are what we believe can be feasible, but this doesn’t mean we have lost sight of others”.

Milliband committed a further £500,000 to develop immature renewable energy technologies such as tidal reefs and fences.

The announcement has led to a mixed response. RSPB Head of Sustainable Development – Martin Harper said “today’s report recognises just how difficult, costly and environmentally damaging the project is likely to be” and Friends of the Earth advocate the smaller tidal lagoon schemes.

Taking a reserved approach, Andrew Lee, chief executive of advisors to the Government -The Sustainable Development Commission (SDC) said “We have an internationally important habitat and also a potential clean energy resource. How we approach this will set a precedent for every other country that’s looking at the same thing in the EU and elsewhere”.

The Severn Tidal barrage seems to experience the same pre-life as Crossrail and nuclear energy – the Government commission studies and chew the fat over and over (they are apparently discovering new insights) – but ultimately they just do not seem to have the will to make a decision about it.