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Wave Driven Generators
nickovs writes "The BBC report that the worlds first commercial power station powered by ocean waves has gone on line. Built by WaveGen, who have issued this
press release, the system uses the swell from waves reaching the shore to force air through a Wells Turbine which has the neat property that it turns the same direction irrespective of which way the air flows through it.
According to WaveGen "It has been estimated that if less
than 0.1% of the renewable energy
available within the oceans could be
converted into electricity it would
satisfy the present world demand for
energy more than five times over". Now wouldn't that be nice?" Nice trick.
Indeed. The Bay of Fundy (yes, you nailed the spelling), which lies between Nova Scotia and New Brunswick (near Maine, for the Canadian geographically-challenged) is home to the highest tides in the world. Some 100 billion tons of water is pumped in and out of the Bay twice a day, every day. It is also the home of the only tidal energy plant in the Western hemisphere.
The Bay of Fundy does produce energy at the Annapolis Royal energy plant, but it only amounts to about 18-20 gigawatts, which equals out to about 1% of Nova Scotia's entire energy use. (Not a lot, in other words.) At last check, it is believed that some 3000 gigawatts of electricity could be produced worldwide through tidal power.
The main problem with tidal power though is that it requires a great difference between high and low tides, at least a 5 m difference. (The Bay of Fundy's high/low tide difference is 17 m.) There aren't too many places around the world with those kinds of tides. Plus, there's the downside that the energy can only be gathered every 12 hours because of the tides.
On the other hand, there are tons of places with waves. Hell, most of the planet is covered with water, so that makes for a lot of beaches. From what I've read, the technology is rather different from the tidal energy used at the Bay. (But then again, IANA hydroelectric expert.)
Since I'm a Nova Scotian, for some reason I know this stuff. Damn Nova Scotian Bay of Fundy propaganda.
J
That seems backwards to me. Removing kinetic energy from the ocean would lessen such effects, I would think. (Am I missing something basic here?)
It would lessen or almost eliminate erosion at the area where the waves _would have_ hit. That's gotta be good for people living there, right?
I think the only people who would bitch about this are the surfers, dude. Total bummer.
Plus if the figure quoted is acurate, 0.1% of the ocean's kinetic energy being able to power the planet - that's a pretty small amount of the total. Plus we already alter our weather in weird ways just by building cities (take a meteorology class - it's an eye-opener!).
I say go for it. It's gotta be better to be powered by that than by what we are now. Take that, windmills, biomass power plants, geothermal, and solar, and it's very technically feasible to power the whole planet without anywhere near the amount of pollution we currently produce. It's just that it's so much cheaper to do it the dirty way. *sigh*
Your concern is that removing kinetic energy from the waves will cause unwanted harm.
Can't happen.
As a wave hits the coastline, it starts to break up. Eventually, it spills over itself and the wave ends. This is the point of zero remaining kinetic energy, and the point of maximum potential energy. The wave retreats, as always.
From what I can tell, this technology uses both kinetic and potential energies to generate electricity. However, it doesn't remove any more energy than the wave would remove on its own. There is absolutely no way that the climate would be harmed by having a man-made structure remove the same kinetic and potential energy from a wave, that it would lose without man's help.
Enjoy.
-Hatta
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