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Inshore sea power

AW-Energy is one of the front-runners in the emerging wave energy industry, and its unique WaveRoller technology has a lot to offer in the quest for harnessing the power of the oceans. The company aims to have a large-scale commercial demonstration plant operational and generating electricity by 2011.

The world’s oceans represent a massive potential source of energy, and ocean energy technology accounts for the largest untapped business potential in the renewables sector. The World Energy Council, for example, has estimated that approximately 2 TW of electricity, or about double current world output, could be generated by wave energy.

A number of concepts have been developed based on making use of tidal currents and wave motion – with varying success – but AW-Energy’s patented WaveRoller is the first solution to harness the surge phenomenon found near the sea bottom at intermediate depths close to shore.

Invisible and safe

The WaveRoller system is based on the use of hinged plates or ‘wings’, anchored to the sea floor in the surge zone and which are moved back and forth by the motion of the water, together with hydraulic rams, which collect the energy generated. This energy can then be converted into electricity using a hydraulic motor/generator system. WaveRoller technology can also be used to power desalination plants to produce drinking water.

As WaveRoller units can be assembled on a modular basis, they are ideal for larger generation schemes. Operating ‘invisibly’ and safely on the sea bottom, environmental and visual impact is minimal. Units do not hinder the natural movement of the water to any significant degree and fishing vessels and other craft can pass over them safely.

AW-Energy’s unique inshore WaveRollers have the potential to be combined with offshore wind and wave energy technologies to create new types of renewable marine energy hubs.

Going multi-wing

Following prototype testing in various locations, a pilot WaveRoller plant has been built off the Portuguese coast at Peniche to test the capture efficiency of the system’s wings. This has proved very successful from a technical standpoint, and has also won the unanimous support of local residents, marine biologists, fishermen, and politicians.

AW-Energy expects to complete a multi-wing design in 2009-2010 and to have a scaled-up plant connected to the grid by around 2011 to demonstrate the capability of the concept for stable, long-term generation. The project has been granted EU funding and industrial heavy-weights such as Bosch-Rexroth and ABB will also be involved.

In parallel with the demonstration unit in Portugal, AW-Energy is looking to participate in site development activities elsewhere in Europe, as well as North and South America and Australia. As the technology approaches full-scale commercialisation, the WaveRoller looks well-placed to challenge offshore wind energy in terms of investment cost and more traditional energy sources when the CO2 factor is taken into account.

> John Liljelund
(Published in HighTech Finland 2010)