Wave and tidal power
The seas around the UK offer an abundant and almost inexhaustible source of energy which could be used to generate electricity from wave and tidal power.
The UK's wave and tidal power resource is huge – but the impacts on UK wildlife could be significant.
Tidal barrages are structures which dam whole estuaries and harvest the power of the tides as the water ebbs and flows. They can produce a substantial amount of renewable energy but the wildlife impacts are potentially very significant.
The RSPB has engaged with a number of proposals for a barrage across the Severn Estuary.
The Severn Estuary and the rivers that feed into it contain a wealth of wildlife, supporting more than 60,000 wintering waders and wildfowl and some rare or scarce fish species. As such it is a protected area nationally and internationally. The most recent barrage proposal was expected to lead to 80 per cent loss of internationally protected intertidal habitat and cause 100 per cent mortality of migrating fish populations in the Severn. The RSPB was not satisfied that less damaging alternatives have been properly assessed and we didn’t believe it would be possible to compensate for the wildlife damage that a barrage would cause. It was also clear that a large barrage on the Severn would be expensive compared with alternative ways of generating renewable electricity. As such we were opposed to this proposal.
The government is currently considering the role of tidal lagoons. Tidal lagoons enclose a large area of an estuary and generate energy as the tides ebb and flow in and out of the lagoon. The RSPB’s 2050 Energy Vision, shows that the UK’s energy needs can be met by energy efficiency and other renewable technologies with lower risk for nature than large scale tidal lagoons.
Tidal lagoons may be able to play a part in the UK’s energy future without harming nature but first we need to understand their wildlife impacts and put in place measures to address this. Developing a pilot project and taking enough time to learn lessons from it is one way to understand how environmentally sustainable this technology could be.
We believe electricity generated from wave and tidal stream could make an important contribution to the carbon-free energy system we need in the UK if we are to combat climate change.
Wave and tidal stream power are emerging technologies. Currently, prototypes are being developed and tested at special test centres across the UK.
Wave energy uses the energy from the rising and falling of waves to generate electricity. Tidal stream devices are underwater turbines driven by fast flowing tidal currents. Tidal stream is different from the technology used in tidal barrages. Both these technologies have the potential to be deliver clean energy at lower risk to wildlife but more funding is needed to help these technologies succeed and to understand their ecological impacts.
Our tidal energy policy
- Every development should be subject to an appropriate evaluation of its environmental impacts.
- Strategic Environmental Assessment is a useful tool which can help ensure decisions about the location of developments are made with a fuller understanding of their potential environmental impacts.
- Tidal barrages pose a very high risk to wildlife and therefore we have not been able to support any barrage proposals to date.
- A well managed tidal lagoon pilot project can help us understand how these could be developed in harmony with nature but currently other forms of renewable energy are cheaper and more wildlife friendly.