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What do an oscillating water column, "tapchan," and a pendulor device have in common?
They're all methods of producing wave power, and they all hold promise to bring us the potential two terawatts (1 terawatt = 1 trillion watts) of electricity that renewable energy analysts say exist beneath the ocean surface.
What is wave power?
Quite simply, wave power
What is it used for?
Wave energy today is used mostly in desalination plants, power plants and water pumping
How is the energy produced?
In all kinds of ways. The devices mentioned earlier are some of the biggest examples of onshore systems: the pendulor device is a rectangular box that has one end open to the sea, over which a hinged flap swings back and forth, providing power to a hydraulic pump and generator. A "tapchan" is a tapered channel system that connects to an above-sea level reservoir and as the channel narrows, the height of the waves increases, causing the waves to spill over into the reservoir. From there, water is fed through a turbine. An oscillating water column, meanwhile, is partially submerged into the ocean. It stores a layer of water inside below a layer of air, so that as waves enter, the level of the water column fluctuates, which in turn causes the pressure of the air column to fluctuate (which, yes, explains the name). When the wave retreats, the reduced pressure sends air through the turbine
There are plenty of other methods being developed and tested around the world, including devices as simple as the Anaconda wave power converter, a British model that consists of a 200-meter rubber tube, submerged in the ocean, with a turbine at one end that is propelled as passing waves create waves within the tube itself.
Existing technologies have a long way to go before wave power can live up to its full potential, but we're getting there, and it'll be well worth the effort.
Where is wave power possible?
Portugal's [url='http://www.treehugger.com/files/2009/03/portugal-pelamis-wave-power-project-dead-in-the-water.php']Agu
