Treading water for energy

Green Ocean Energy is preparing to unveil a scale prototype of a new wave energy device called the Ocean Treader.


Green Ocean Energy, based in Aberdeen, is preparing to unveil a scale prototype of a new wave energy device called the Ocean Treader.


The company has developed the device along with another machine called the Wave Treader.


The company said that the devices harness wave energy and convert the motion into electricity, using similar technology. 


Wave Treader attaches to an offshore wind turbine, providing combined wind and wave energy to boost the relatively low efficiency rates of stand-alone offshore wind turbines.


Ocean Treader is a stand-alone, floating device designed for offshore ocean deployment.


‘Interest in our technology has mushroomed since the results of our feasibility test into Wave Treader were announced earlier this year,’ said George Smith, managing director.


‘We are in discussions with a number of energy companies and financial backers, with a view to installing a full-scale prototype early next year.


‘Commercialisation of Wave Treader is anticipated by 2011.


‘This is a really exciting time for the renewable energy sector, with a range of new technology being pioneered,’ he added.


‘It’s great to see so many Scottish companies right at the forefront of the sector, and I look forward to discussing our technology in more depth during All Energy.’


The devices developed by the company comprise a sponson at the front, a spar buoy in the centre and a second sponson at the back.


As the wave passes along the device, the forward sponson lifts and falls, then the spar buoy lifts and falls slightly less, and finally the back sponson does the same.


The relative motion between these is harvested by hydraulic cylinders mounted between the tops of the arms and the spar buoy.


The cylinders pressurise hydraulic fluid which in turn spins motors that generate electricity.


Each device can generate up to 500kW of electricity, which Green Ocean said compares favourably with other devices in the marketplace, given their compact size.


The scale prototype is currently undergoing testing at the New and Renewable Energy Centre (NaREC) in Blyth, Northumberland, and in the wave tank at the University of Strathclyde.


The results of the latest round of testing are expected to be announced next month.