In 1993, Norwegian professional diver Rauno Koivusaari was exploring a shipwreck in the Baltic when he was almost hit by a bulkhead door that was flapping slowly back and forth in powerful underwater waves. Most divers have noticed this phenomenon, but Rauno began to wonder if this bottom wave energy could be harnessed and founded AW Energy to find out.
With a €1 million venture capital investment from Fortum, an electricity group also based in Norway, AW Energy came up with WaveRoller. The device captures kinetic energy at the sea bottom using a specially designed moving wing, which is then converted into electricity using traditional technologies. AW has so far had two 10kW prototypes installed in 'real sea environments' in Portugal, the most recent being in 2008. The prototypes have proved very successful from a technical standpoint and have won the unanimous support of local residents, marine biologists, fishermen, and politicians.
Modular wings
The WaveRoller system features hinged plates, or ‘wings’, anchored to the sea bottom, which are moved back and forth by the surge movement of the sea, and hydraulic cylinders, which collect the kinetic energy generated. This energy can then be converted into electricity by a hydraulic motor/generator system. WaveRoller technology can also be used for desalination purposes to produce drinking water.
The concept is a modular one, with each module comprising between three and five wave elements. As there is no upper limit on overall capacity, it will be easy to ramp up capacity by simply adding new modules. Maintenance is also easy, thanks to the fact that each module is mechanically independent, which also means that electrical output can be maintained while one or more modules are being worked on.
Environmental and visual impact is minimal, as WaveRoller elements do not significantly hinder the natural movement of the water, and coastal craft, such as fishing vessels, can pass over them safely.
Commercial launch planned for 2013
Now, AW Energy is readying itself for the launch of its first demonstration unit in October of this year. In an interview with New Energy Finance, CEO of AW Energy John Liljelund said that preparations for the project began last year and that the goal of the demonstration is to “manufacture and deploy the first grid-connected WaveRoller unit. A one-year test period is included in the project and the nominal capacity of the demo unit is around 300kW”. The company expects to launch its first commercial-scale device “around 2013”.
Liljelund said that the demonstration unit is “very similar to the future commercial scale unit which will have a nominal capacity of around 1.2-1.8MW, depending on the resource at the future installation sites”.
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