The UK is to study in-depth the feasibility of harnessing energy from the Severn Estuary, which has one of the greatest tidal potentials anywhere in the world.

The two-year study will not only analyse the potential impacts of such a major tidal power scheme, but also identify a preferred project, which could consist of a single technology in one location or a combination of technologies.

The feasibility study will examine how tidal barrages and lagoons could unlock the huge potential of the Severn Estuary. It will also enable the government to decide whether it could support such a project.

“The potential scale of this project, and the impact it could have for both securing energy supplies and tackling climate change is breathtaking,” said Energy Secretary John Hutton. “The Severn Estuary has some of the best tidal potential in the world and could more than double the current UK supply of renewable electricity, and contribute significantly to targets for renewable energy and CO2 emissions reduction.”

The Severn Estuary is one of the largest estuaries in the UK. Its classic funnel shape, unique in the UK, helps give it the second highest tidal range in the world.

A recent report from the UK’s Sustainable Development Commission (SDC) indicated that a barrage scheme, involving the construction of a hydroelectric dam, could generate around five per cent of the UK’s electricity demand.

The study will be restricted to tidal range technologies and will not include tidal stream technologies. It will include a Strategic Environmental Assessment (SEA) and will culminate in a full public consultation in early 2010.

The SEA will assess broadly the environmental, social, regional, economic, and energy market impacts, costs and benefits of a power generation scheme. The SDC’s recent report indicated that the environmental impacts of such a project could be significant, and that a number of key criteria would have to be met for it to be considered truly “sustainable”.

“We must understand the cost and the impact that a project of this scale could have, not least the environmental, social and economic effects. But the need to take radical steps to tackle climate change is now beyond doubt,” said Hutton.

The feasibility study will also look at the ways in which the government could support a tidal scheme and whether the government’s climate change goals could be met in other ways.

The Severn Estuary is of National, European and International nature conservation significance – and so has been afforded the corresponding levels of legal protection. Any tidal project would there have to comply with a wide range of environmental legislation.