A wave power device, the Wave Treader, that piggybacks on new or existing offshore wind installations has been unveiled by Aberdeen-based Green Ocean Energy Ltd. By using the infrastructure of the wind turbine installation the Wave Treader gives additional electrical output while using the same cabling and structure, says the company. 

The Wave Treader has now achieved proof of concept and a full size prototype could be ready for testing in 2010. Each Wave Treader machine generates approximately 500 KW which is enough electricity to power 125 homes.

Managing director of Green Ocean Energy, George Smith, who invented Wave Treader said: "We have drawn on our extensive skills and experience in the energy sector to develop this technology. The support we have received from npower through the juice fund has enabled us to take a huge step forward in preparing the device for widespread use in the offshore environment. These are exciting times for the company and we look forward to eventually seeing the device incorporated into offshore wind farms."

The Wave Treader comprises sponsons mounted on the end of arms both in front and behind the turbine’s column which is vertically mounted on the seabed. Hydraulic cylinders are attached between the arms and an interface structure and as the wave passes along the device the sponsons and arms lift and fall stroking the hydraulic cylinders. The cylinders pressurise hydraulic fluid which, after smoothing by accumulators, spins hydraulic motors and then electric generators. The electricity is exported back to the shore through the same cables used by the wind turbines.

Uniquely, Wave Treader can turn to face the direction of the wave train to ensure maximum operational efficiency. It also has active on-board adjustments to allow for the effects of tidal range.