As the UK is surrounded by miles of coastline and either seas or oceans, it has easy access to wave power and tidal energy. The coastline extends for over 11 000 miles and the tidal ranges are some of the greatest seen anywhere in the world. The difference in sea level between low tide and high tide in the Severn estuary, for example, is over 15 metres. It is this difference that can be exploited when tidal power is used to generate electricity. So why does the UK not have a thriving alternative energy supply that makes use of wave power?
Wave Power is Green, Power Plants Aren’t
The simple answer is fairly obvious – the natural coastline is generally very beautiful and supports a rich diversity of plant, animal and marine life. Building a huge tidal power station in an estuary would completely disrupt the ecosystem and would be environmentally extremely destructive. The damage to the natural environment generally holds back successive governments, who have decided it would make them very unpopular to build the installations necessary to supply the UK with wave power generated electricity.
In the mid 2000s it became clear that a proposed scheme to set up a tidal power generation facility in the Severn Estuary – called the Severn Barrage – was doomed never to get past the drawing board. It could have supplied a twentieth of all the electricity used in the UK by the year 2010. Although it would have cost nearly £15 million, the major problem was always its likely impact on the estuary and public objection.
Is Wave Power Feasible?
Generally, yes it is highly feasible. A test area off Orkney is helping to develop wave generators for use elsewhere in Europe – a recent testing project has been used to develop a wave farm in Portugal. There are several estuary sites in the UK where it would be possible to establish a tidal power station but, due to the environmental concerns, these have never got past the early planning stages. The UK is not the only country to have these concerns – no country in Europe, apart from France, currently has a tidal power station. The only one in existence was built off the northern coast of France back in the 1960s, in the Rance estuary. It has been steadily contributing to the French power system since then.
Alternatives to Tidal Power Stations
Researchers are trying to develop alternative technology to harness the power of the waves without completely destroying the natural environment. One possible solution is the use of submerged turbines, which are fixed to the sea bed, and so which cannot be seen. The turbines can be position in areas where the undercurrent is strong, but they do not affect the tides and they do not have a very high environmental impact. They are more difficult to set up – all the installation and maintenance work has to be done at the bottom of the sea.
Early tests have been quite positive, however, and the demonstration that a small submerged array of generators and turbines could generate easily as much energy as the proposed Severn Barrage scheme, was probably the final piece of evidence that the government needed to decide never to go ahead with the scheme in the Severn estuary.
Other research projects are still very much at the design stage but there is strong commitment both from central government and from the Scottish Assembly to put up money to encourage further development.