A Scottish company, AWS Ocean Energy Ltd., that had slipped under my radar, has secured £2.128 million (US$4.16 million) in funding from the Scottish Executive. The funds will be used to develop and commercialize AWS’ Archimedes Wave Swing, claimed to be one of the few proven technologies worldwide for generating clean, renewable electricity from the ocean’s waves.
The Archimedes Wave Swing, shown left (
artist apparently took some liberty by showing it above the water surface), is submerged at least six meters below the sea surface which, as well as removing visual impact and hazards to shipping, avoids high storm impacts. Compared to most other wave energy devices, the Wave Swing also takes up a proportionately smaller area of the sea, in relation to power generated. Following a successful pilot project in Portugal, the £2.128 million will be used to develop a pre-commercial model of the device at the European Marine Energy Centre (EMEC) in Eday, Orkney.
Around 25 meters high and 12 meters in diameter, the commercial units will be rated at 1 Megawatt generating around 3,000 Megawatt hours of electricity in a typical year.
AWS believes that this work will lead directly to the construction of the first mini wave farm of Archimedes units in Scottish waters, by the third quarter of 2010, expanding within 12 months to 20 units.
The wave swing is described as follows on their web site:
The AWS wave energy converter consists of a large air-filled cylinder which is submerged beneath the waves. As a wave crest approaches, the water pressure on the top of the cylinder increases and the upper part or 'floater' compresses the air within the cylinder to balance the pressures. The reverse happens as the wave trough passes and the cylinder expands. The relative movement between the floater and the fixed lower part or 'basement' is converted directly to electricity by means of an innovative linear generator. First-generation machines will be rated at over 1MW and have a load factor in excess of 35%.
The device is intrinsically simple with only one main moving part - the floater. Ancillary systems are limited to ballast water pumps, an integral damper to absorb excessive power and modules for air supply control and lubrication. All will use existing sub-sea technology and be capable of maintenance during rough weather using ROVs.
The complete system has been tested at full-scale via a pilot plant that is installed off the coast of Portugal. Engineering for the pre-commercial demonstrator is now ongoing.
Source: Alternative Energy News
There are now several companies in the ocean power category that are developing wave power technologies and have advanced pilot or demonstration plant projects. It looks like the first commercial plants will be operating by 2010 or sooner. The AWS design looks like one of the simplest and should have a good chance at becoming a winner. Ocean power stands a chance of having less trouble getting permitting because they are much less intrusive than wind power, which should enable them to be located in some areas where strong opposition to wind power has been found. Wave power depends on wind generating waves, so there potential locations are similar to those for wind power, there are some areas that have strong currents that are also suitable for ocean power, but not this particular version. I would think that ocean power, when developed, should have similar or slightly lower cost than wind power, but that is pure speculation at this time.
As an aside, I get excited every time I here about some activity at the European Marine Energy Center at Eday, Orkney, because my Fraser ancestors emigrated from Eday to the US in about 1840. I visited Eday about six years ago and found the people there extremely cordial and total strangers gave me a day long tour of the little, 8 mile long by 2.5 mile wide island, population about 120.