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New Generator Boosts Wind Turbine Efficiency 50%
MagnetDroid writes "A startup company based in Vancouver has developed a new kind of generator that could harvest much more energy from the wind. The design could not only lower the cost of wind turbines but increase their power output by 50 percent to as much as 100 percent, in some locations. Normally, when wind speeds drop, a turbine's engine becomes less efficient. The new engine, from ExRo Technologies, runs efficiently over a wider range of conditions. The design replaces a mechanical transmission with what amounts to an electronic one. Magnets attached to a rotating shaft create a current, but individual coils can be turned on and off electronically at different wind speeds." The company will begin field-testing a small, 5KW wind turbine by early next year.
Since when is an increase of efficiency by 100% impossible?
For arguments sake, let's say that current wind turbines are 10% efficient. This new turbine is therefore 15% to 20% efficient.
But will this make home wind turbines effective purchases? I doubt it.
I hope the design can be retrofitted into existing turbines, since there are so many deployed now.
No.
The generator is more efficient in changing wind conditions. When the wind is faster, it turns on more coils to provide greater mechanical resistance and takes more energy out of the wind. When the wind is slower, the turbine can still run because the generator can be switched to take less energy out of the wind.
This isn't a consideration for regular power plants because the amount of energy sent to the turbine is well-controlled and doesn't vary with time like wind speed does.
I claim first use of "Error No. 0B" - or "No. 0B error." It'll be the new ID 10T!
"The design could not only lower the cost of wind turbines but increase their power output by 50 percent to as much as 100 percent, in some locations."
100%? Why stop there?!
Because, due to this having not a damn fucking thing to do with perpetual motion or snide remarks regarding such, there's only so much energy that can be extracted from the wind. Getting a 1.5x to 2x boost -- over the course of a year, meaning combining periods where the windmill was operating efficiently, and those times where it was not -- is great. I don't know why you phrased your question the way you did.
Oh, and, uh.. why is this whole article about windmills? Couldn't these improvements in generator efficiency be used across the board?
Not really. The majority of turbine generators are designed to operate at a single, optimal frequency. Wind however is by its nature variable, so to get peak efficiency across various RPMs requires some extra ingenuity. Maybe this could be applied to your car's alternator, I don't know.
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About a month ago, I was travelling on I-68/I-70 in Maryland, over the Cumberland Gap, when I saw a several wind turbines in the distance. After I got over the neat factor (even though we have them here in WV), I quickly realized that with each revolution of those turbines, we could/would be cleaning up the environment that much more. That alone makes me back this program 100%. Will it reduce foreign dependency as well? Let's hope so.
But, we are all going to have to get over seeing them as ugly or migratory-bird killers for this program to work. I truly want a future where we use very little foreign energy, and we harness renewable energy sources. I say we get those new turbines into the wild as quickly as possible. T. Boone Pickens, get to work!
So let me get this straight -- it's more efficient, has fewer moving parts, has a higher power output, and is cheaper to mass produce? Buy that engineer a beer! This is a real leap forward in a machine class that hasn't made more than incremental improvements for awhile now. The spirit of Nikoli Tesla approves. Next question: Can this technology be adapted for use in the hydroelectric industry? I think it may be possible, and it would reduce maintenance costs somewhat -- maybe we could throw out the sluce gates and make water flow through the dam with fewer electromechanical parts?
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power output != efficiency
FAIL
http://greenobyl.com/ please.... think of the children!!
That's 100% of the maximum possible output of the generator. Not 100% of the energy that comes into it being converted into electricity.
The words, they MEAN things.
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The biggest problem with CVT technology is that currently it's pretty weak. CVTs in cars can only handle about 300HP (~230KW); a 5KW+ turbine would snap that like a matchstick. And one big enough to handle that turbine would sap quite a bit of efficiency.
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I haven't done anything to work this out, but I do think the effect is negligible. Most of these turbines are 200-250' tall - so on the order of a 20-30 story building. We build those all the time, without worrying about affecting weather patterns (though they may have a very local effect). But the turbines are much less disruptive to the wind than the building even - they just slow it down a bit, rather than blocking it all together. So, other than causing storms to more often go around the wind farm itself, I can't see this really affecting global or even continental weather patterns.
What if the wind blows at X 80% of the time, and gusts above X 20% of the time?
You're assuming that they're trying to squeeze more energy from the low end of the range, I think they're actually trying to catch the period gusts that are above the normal range. Increasing the resistance will make the windmill safer (and more effective) to operate at higher speeds, until a certain limit is reached where it just has to be shut down for safety.
-t.
Just out of curiousity, and I haven't RTFA yet so maybe the answer is there, but couldn't you vary the pitch of the vanes on the turbine to maintain a constant RPM in varying wind conditions, much the way a constant speed propeller on an airplane works?
They do that too, even on existing windmills. The problem is that when the wind speed is low, there's nothing you can do to make it go fast, so if you wanted to maintain constant RPM in the generator, you'd have to pitch the blades to give very low speed in high winds, which is rather counter-productive. Adjusting the resistance of the generator so it works across a wider band of RPMs, combined with adjusting blade pitch, provides much better results.
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Even taking into account the increases in efficiency this would provide, it still doesn't solve a fundamental problem - if the wind isn't blowing, power won't be generated. Certainly in this part of the country (Ontario), there are periods of time, days long, when the wind will not blow. And the province still needs the same amount of power regardless of the present wind speed. If the power can't be counted on, then backup generator stations will need to be built to generate power when the wind can't. And wind power is far more expensive than other sources of power. At least twice as expensive in most cases, if not a good deal more, from what I understand. So not only is it more expensive when it does work, but even more money will need to be spent to provide backup power when it doesn't. Aesthetics and health also must be taken into account. While some find them beautiful, to many they are an offensive blot on the landscape, particularly in serene, peaceful, or sublime areas. Their noise production is not insignificant for those living nearby. And recent studies show they can have a negative impact on human health when people are located close enough to them. So if wind power is to be used, the installation should be done in such a way that it will not destroy the beauty of the landscape we are trying to preserve, while recognizing that backup power will still need to be built.
If you do some research into wind power, you will see it is exactly the problems with putting 2MW low rev capable gearboxes at the top of towers that has led to this electrical solution. Wind turbines turn very slowly, hence the tooth loading on any gearbox, planetary or not, is enormous. Remember that at any given time the entire loading is on one or two teeth per gear, and that includes shock loads which are worsened because of the inertia of the rest of the gear train. What's more, your solution requires a 90 degree bevel drive, and these are very difficult indeed, as well as expensive, to engineer well at high powers. (The low speed gearbox problem is one reason that ships are propelled by very low speed direct drive Diesels; to get the desired low prop revolutions it is actually better and more efficient to make vast longstroke engines doing around 75rpm than to gear down physically much more compact medium speed engines. Even crankshafts 300mm in diameter sometimes break in heavy seas. Imagine the loading on a single gear tooth.)
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