Severn Estuary Tidal Power Consultation - Resource Page

Few people interested in the Severn estuary and the surrounding area can be unaware of the debate about harnessing the power of the tides. It is the biggest issue currently affecting the estuary and one which the Severn Estuary Partnership is keen to see properly debated.

The UK Government is committed to generating 20% of the nation's energy from renewable sources by 2020, while the Welsh Assembly Government target is for 4 terawatt hours of electricity to be generated from renewable sources by 2010. This latter target will require 800MW of additional installed capacity from onshore wind resources in Wales, and 200MW of additional capacity from offshore and other renewables. A tidal power project in the Severn estuary could also contribute to the UK’s commitment to meeting the European Union’s Renewable energy target along with domestic and international greenhouse gas targets. Developments in the Severn estuary, with a tidal range of 14 metres (the second largest tidal range in the world), could therefore make a major contribution to meeting both these ambitious targets, but any scheme is inevitably going to have a significant impact on habitats and wildlife. It is also claimed that some proposals could also limit the entry of shipping to the ports of Cardiff, Bristol, Gloucester, Newport and Sharpness.

A number of organisations have stressed the need for an open public debate in order to help identify the best way of capturing the enormous renewable energy resource of the Severn estuary whilst safeguarding its internationally important combination of species and habitats and bringing lasting benefits to local communities. The Government’s Severn Tidal Power Feasibility Study Consultation is therefore gathering and assessing evidence to enable Government to decide whether or not to support tidal power development in the Severn Estuary.

In July last year the Government published a list of ten possible schemes, including barrages, onshore and offshore lagoons, a tidal fence and a tidal reef. They then assessed, in high level terms, the costs, benefits and impact of potential schemes and how they might affect the environment and the region. Following this process Ministers have now recommended the following schemes for detailed analysis:

• Shoots Barrage - located near the Severn road crossings, estimated to cost £3.2bn to construct and generate 2.7TWh/year or just under 1% of UK electricity
• Beachley Barrage - slightly smaller and further upstream than the Shoots Barrage (and upstream of the Wye), estimated to cost £2.3bn and generate 1.6TWh/year
• Fleming Lagoon - an impoundment on the Welsh shore of the Estuary between Newport and the Severn road crossings, estimated to cost £4bn and generate 2.3TWh/year
• Bridgwater Bay Lagoon - an impoundment on the English shore of the Estuary between Hinkley Point and Weston Super Mare, estimated to cost £3.8bn and generate 2.6TWh/year
• Cardiff-Weston Barrage - located between Brean Down and Lavernock Point, estimated to cost £20.9bn and generate 16.8TWh/year or some 4.4% of UK electricity.
  

New Scientist Map of short list	Original long list of options

It is important to note that the Government is not seeking views in this consultation on whether or not to build a Severn barrage or other scheme. They will be asking for views on this in a second public consultation, probably in 2010, once there is detailed information on the costs, benefits and impacts of the short-listed schemes.

The five projects selected are those that the government's engineering consultants, Parsons Brinckerhoff, deemed to be based on the most proven technology. Proposals for tidal reefs and tidal fences are not included. The former would involve a series of slow-moving, fish-friendly turbines over a purpose-built causeway in the estuary while the latter would involve building only a partial barrier between Cardiff and Weston-Super-Mare. Both these proposals are acknowledged as having minimal impact on the local environment.

There have been allegations that Parsons Brinckerhoff miscalculated the costs of a tidal lagoon project championed by Friends of the Earth. The report sent by the consultants to ministers stating the tidal lagoon option would be eight times more expensive than the barrage scheme and would not generate as much power, claims denied by the designers. David Elliott, of the energy and environment research unit at the Open University, has also stated that a single big barrage would be problematic in terms of harnessing energy since it would only provide two short bursts of power every day. He considers that several smaller tidal turbines around the coast, operating at different times, would be a better solution. Likewise the RSPB is disappointed that the Cardiff-Weston barrage option is on the short list, considering that the final scheme must be the one that generates as much clean energy as possible, while minimising harm to the estuary and its wildlife. They consider that the barrage would destroy huge areas of estuary marsh and mudflats used by 69,000 birds each winter and block the migration routes of countless fish.

The Partial Impact Assessment of Severn Tidal Power prepared for the Department of Energy and Climate Change compares the five projects against the “do nothing” option, which is considered to be the generation of electricity from Combined Cycle Gas Turbines and other options for meeting renewable energy and GHG targets. It also states that there may be a regional economic cost to ports and to local fishing, additional environmental costs from the loss/damage of habitats and species, reduced ‘ecosystem services’ including negative effects on biodiversity and harm to fish stocks.

Because of these issues and others, the Sustainable Development Commission, the UK Government’s independent watchdog on sustainable development, set out three ‘sustainability tests’ which a Severn tidal power scheme should pass:

• It must be publicly led as a project and publicly owned as an asset, in order to avoid short-termist decisions and ensure the long-term public interest
• It must go ahead in full compliance with EU Habitats and Birds Directives, which will require assessment of mitigation and compensation on a scale as yet unseen in Europe
• Any tidal power scheme must not divert Government attention away from much wider action on climate change

The Severn Tidal Power Consultation phase closed on the 23rd of April. For the latest information on the second phase of the study, please visit the Department of Energy and Climate Change's Severn Tidal Power Feasibility page, or the Welsh Assembly Government's Severn Tidal Power page.

A second public consultation will be held, probably in 2010. This will still be before any final decision is made by the Government on whether to support a Severn tidal power scheme.