Rival designs race to harness ocean energy

[Wakeupcall]

In recent months, many new ideas for harnessing the abundant but elusive energy of waves and tide have entered tests, or even full-scale use.



The world's first commercial wave "farm" only began operating last year, off the north coast of Portugal.

Each Pelamis generator is a 150-metre-long steel jointed structure, which flexes to drive hydraulic generators and produce 750 kilowatts of power.

(Image: Pelamis Wave Power)



Marine anaconda

This is a mock-up of a novel design to generate electricity from waves. The Anaconda's rubber body is flexible and filled with seawater.

Waves create travelling pressure waves inside the Anaconda, driving a generator in the tail.

See video of a 1/25th scale prototype undergoing trials.

(Image: Checkmate)



Distant turbines

This buoy is part of a trial wave power plant near Fremantle, Western Australia.

Each buoy bobs up and down as waves pass, driving seawater through pipes along the sea floor and onto land, where turbines generate electricity.

(Image: CETO)



Piston power

These buoys are designed to remain at least 6 metres underwater.

The top half of each is forced down by each passing wave, before it pops up again to its previous position.

This process compresses gas inside the buoy, driving it through an onboard generator.

(Image: AWS Ocean Energy)

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[Wakeupcall]

Renewable rig

This floating rig is currently in dry dock in the UK, awaiting deployment off the east coast later this year.

Floats are attached to each of the vertical shafts so that passing waves will pump them up and down.

This will allow linear generators connected to each shaft to produce electricity.

(Image: Trident Energy)



Tidal turbines

This platform, SeaGen, has two turbines mounted on it.

It was installed in the tidal currents of Strangford Lough, Northern Ireland, in 2008.

It supplies 1.2 megawatts of power to local houses.

(Image: SeaGen / David Erwin)



Swimming test

This 3-metre-tall scaffold, built by UK company company TidalStream, was recently tested in a pool in France.

It is designed to be scaled up by 20 times, and should be able to harness the energy of currents in tidal channels.

(Image: TidalStream)

[source]

[myksav]

They will never work!

Just getting that in before the technophobes do.

Of course, nothing like that would ever work in Irish waters and hands. Shure, we can't do anything like that, we're Irish.

[wombat]

Open hydro, based in Louth has a device for using ocean currents which works but is it commercial? There are huge difficulties associated with wavepower - the very power you want to harness makes you need very strong structures. Basically Newton's law of action and reaction are equal and opposite.