Anaconda joins wave energy hunt

Innovative design boosts hopes for UK marine power

The world’s largest snake, which hunts its prey in water, has given its name to a pioneering new device for generating electricity from waves. The Anaconda’s simple design, involving few parts, should help make it reliable and low maintenance, say its developers Checkmate SeaEnergy – while its ability to capture energy in a wide range of wave conditions means it could generate power at a much lower cost than other contenders in the nascent wave energy industry.

A closed cylinder of rubber up to 200 metres long and filled with water, tethered to the sea floor so it faces head on into the waves, the Anaconda uses the incoming wave’s upward motion to start what is termed a ‘bulge wave’ in the pressurised water trapped inside itself. This bulge then rides the front of the wave, in a similar fashion to a surfer, as it travels the length of the cylinder. At the far end is a two-chambered ‘power take-off’ section, where the ‘bulge wave’ arrives as a pulse that flows from the upper chamber to the lower one, driving a turbine as it goes. The resulting power is then fed to shore via a cable while the water returns to the system through a one-way valve.

“This is a novel concept which captures energy continuously from the wave as it passes, enabling it to capture far more energy per wave,” says project director Tom Roach, from the Checkmate Group’s Flexible Engineering division. “Being below the surface it has virtually no visual impact, and as no water is sucked in or expelled from the system it poses very little risk to sea life.”

The Anaconda is only at early stages of development, but it could be deployed off the UK coast within five years, claims Professor John Chaplin, one of the researchers leading the project. The Carbon Trust’s marine energy accelerator manager Stephen Wyatt, tasked with bringing along the most promising candidates, has high hopes for the Anaconda. “It appears to have potential to make a step change reduction in the costs of wave energy,” he says. 

“Marine power is still in its infancy,” admits a spokeswoman for The Department for Business, Enterprise & Regulatory Reform, but adds that “this is an exciting and evolving sector with the potential to make a significant contribution to the UK's energy generation mix in the medium to longer term.” To help meet its targets on renewable energy, the government is hoping to increase the installed capacity of marine technologies (wave and tidal) from next to nothing at present [see box] to some 2GW by 2020. – Julia Sussams

3 October 2008

Julia Sussams