Green Ocean Energy Ltd, the Aberdeen-based renewable energy company, has developed a wave power machine which uniquely attaches to an offshore wind turbine thereby giving combined wind and wave power from one installation. The economics of both machines will be enhanced as the expensive infrastructure such as the foundation and cabling will now be shared. Tests have recently proven that the system is highly effective and the device is a step closer to commercial use.
Green Ocean Energy was able to develop the Wave Treader technology after securing funding to the tune of £60,000 from npower’s Juice fund which is a unique scheme that supports the development of wave and tidal technology.
The financial backing enabled the company to put the device through a feasibility study into its commercial application. The Wave Treader has since achieved proof of concept and a full size prototype could be ready for testing in 2010.
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 has the potential to significantly increase sustainable energy generation both in the UK and around the globe. If we’re going to reach the Government’s target of generating 20% of the UK’s energy from renewable sources by 2020 it’s essential that a range of sustainable sources are put into widespread use.”
Green Ocean Energy was established in 2005 with the aim of generating ample, clean and sustainable energy by harnessing marine energy in ways that are harmonious to the environment and economically viable.
Each Wave Treader machine generates approximately 500 KW which is enough electricity to power 125 homes.
Helen Steed of npower’s Juice fund commented: “We are delighted with the results of the Green Ocean Energy Wave Treader. The device is the first of its kind, and shows tremendous potential in utilising existing off-shore infrastructure to generate clean renewable energy. This is exactly the type of project that npower juice fund was developed for.
“Research and development are the cornerstones of the npower juice fund ethos, and provide additionality to npower juice. For every customer that joins npower juice, npower invests £10 per year per customer into the juice fund. To date npower juice fund has invested £2m into the development of marine renewable industry”
The Wave Treader has been developed using the core concept of a stand-alone wave power device called Ocean Treader which is also being developed by the company. Mounting the device on the foundation of an offshore wind turbine makes that technology more commercially viable because of the relatively low technical risk.
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.
With a design life of 25 years the machines have been designed to ensure they are highly reliable and use standard marine equipment.
The company is now looking to attract further investment to enable continual development of the company’s products.
Key Features of the Wave Treader
Projected over 500 KW rating.
Infrastructure overheads shared with Wind Turbine giving higher profitability.
Higher Yield per unit area of Sea.
50m long, 20m beam.
Very few Single Point Failure modes will lead to a high level of reliability.
Standard, Proven Marine Construction – Steel & GRP.
Major mechanical components are standard Marine Specification ‘off the shelf’ items.
25 year design life, 5 years between major refits.
Modular design means ease of component change-out.
Simple design will mean low manufacturing costs and high reliability.
Low levels of intrusion to the marine environment