The UK is ideally placed to capture the power available from tidal currents in Europe. Scotland is a leader in the research & development needed to tap this enormous potential and is gearing up to export scientific knowledge & technology to regions round the world. Aberdeen’s Robert Gordon University recently challenged 60 students from schools around the UK to design a solution for providing electricity to a fictitious island off the coast of Scotland, as part of a project to turn on young people to science.…
As well as looking at traditional sources of power, they studied three alternatives – including tidal energy – to understand the role renewables could play in the future.
But the focus of Professor Ian Bryden’s work is not science fiction. Formerly the head of RGU’s Sustainable Energy Research Group, now Professor of Renewable Energy at the University of Edinburgh, Ian Bryden has been developing solutions for the real world, including a device which could harness the power of the tides around Scotland to generate an estimated 15-22 terawatt hours every year – enough to meet six per cent of the UK’s total energy needs.
Tidal currents could also provide a clean source of power to many other countries, and the “Snail” built by Bryden’s team in Aberdeen could be the first tidal-power solution to be widely adopted worldwide for commercial electricity production.
“It started as an intellectual exercise,” says Bryden. “Our challenge was to build an economical, working device by solving the most difficult problem in tidal power – how to anchor energy-extraction machines to the seabed.”
According to Bryden, the Snail can be transported on a flat-bed truck, then towed to its location by a tug, and stay on the seabed – without using ballast or drilling a hole in the seabed. “There are huge drag and lift forces in the ocean, but by using reversible hydrofoils, we use those same forces, plus friction, to keep the Snail fixed in position,” he explains.
The Snail is just a small part of the work going on in the Centre for Research in Energy and the Environment at RGU, but it does provide a practical example of the kind of machines that the team can develop, by first addressing fundamental scientific issues. In Bryden’s view, technologists as well as investors could easily make costly errors by putting too much emphasis on energy converters, instead of the science – which could make the turbines work better without ‘reinventing the wheel’.
Presently capable of generating 100-150 kilowatts of power, future versions of the Snail could produce up to one megawatt or as little as 10kW, and would work best in regions where the currents are strongest – e.g. the Pacific. Another big advantage is that Snails could be located very easily in deep or shallow water, unlike devices secured to the seabed, which are more suitable for depths of 25-50 metres. This means the “small-is-beautiful” devices could be used in more places worldwide.