Helen Blenkharn, RSPB Climate Change Policy Officer

Last week we posted a blog on our concerns about proposals for a Severn Barrage that are being discussed by a Government committee. The project would involve a shore-to-shore barrage across the Severn Estuary, with potentially catastrophic consequences for the world-class habitats and wildlife that exist there. Barrages such as this are an engineering feat on a huge scale, and their impacts can extend far beyond their immediate location and for many years after they’ve been built.

What isn’t always clear though, is that the RSPB supports the development of wave and tidal technologies. However, we’d like to see a balanced, step-by-step approach that allows new systems to be tested and monitored, rather than leaping into a project on such a huge scale that it excludes all other options. In the longer term, we think taking this phased approach will mean we can deliver more renewable energy without unacceptable impacts on wildlife.

A barrage isn’t the only way to harness the renewable energy potential of the Severn, or other estuaries around the UK for that matter, and there are a range of more innovative, and potentially less damaging, technologies that need to be considered. For example, tidal lagoons use the same technology but apply them in an arc from a single point on the coastline. If sited appropriately this approach could have far fewer impacts than a barrage – they’re likely to affect the tidal patterns over a smaller area and should be less of a barrier to fish. They’re also smaller in scale so should have less impact on intertidal habitats like mudflats.

There are a range of new wave and tidal devices under development, like Pelamis below which uses the motion of waves to generate electricity. Tidal stream devices are currently dominated by machinery similar to wind turbines but positioned beneath the water. They use the energy in the tides to turn the turbines and can be arranged together in a ‘tidal fence’. You can read a good introduction to the different technologies that are currently under development in a report that RegenSW and partners produced for the Bristol Channel last year.

Pelamis wave device at the European Marine Energy Centre in Orkney (copyright free)

However, it isn’t all plain sailing. The wave and tidal industry has two big problems and they’re closely linked. One is that it’s incredibly expensive to develop new technologies and roll them out on a commercial scale. They need willing investors, and that’s the second problem - lack of certainty about Government support for different renewable technologies means that investors are very hard to come by. Even if they manage to overcome both of these hurdles there’s still the difficulty of getting access to the electricity grid which can need expensive new infrastructure.

Yet the picture isn’t all doom and gloom. Over the last few weeks and months a number of big announcements suggest that the tide may be turning. Last year the Government announced the launch of two ‘marine energy parks’, one in the south west in Cornwall, and the other in the Pentland Firth and Orkney Waters in the north of Scotland. These areas have shown leadership in driving forward the development of wave and tidal technologies and both have new research and testing facilities, including  The Wave Hub in Hayle and  the European Marine Energy Centre in Orkney, which has just been granted £4.1million from the Scottish Government to boost their research.

New funding is also coming on stream. Last week the UK Government announced new funding to help drive forward growth in the UK’s marine energy industry. Two British companies, MeyGen Ltd and Sea Generation Wales Ltd were offered a share of £20 million under the Marine Energy Array Demonstrator scheme. They’ll use the money to test marine devices in arrays out at sea. And the Crown Estate has invited applications for a share of another £20 million to support the construction of projects involving several devices in an array.

In the UK we have a wealth of wave and tidal resources, and some of the best researchers in the world. It a no-brainer that we should support this developing industry and seek to establish the UK as a world leader.

Do you think the Government should be doing more to help new wave and tidal technologies get off the ground and ino the water?