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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.
Wind energy is a lot like politics and advertising. The more it blows, the more spin you see.
-=Bang Bang=-
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?
#fuckbeta #iamslashdot #dicemustdie
TFA doesn't mention specific percentage improvements in efficiency. That was kdawson's contribution, and then only in the poorly-worded headline. TFA is claiming that the overall output of a given wind turbine could be boosted by 50% or more by altering the dynamics of the generator to make it more efficient over a wider range of wind speeds.
Basically, turbines are most efficient at a given speed, and efficiency drops off for anything outside of that, whether faster or slower. This new design attempts to address that by decreasing the amount by which the efficiency drops off at different speeds. The improvement in the efficiency curve boosts overall power output, as the turbine isn't as strictly limited to a given wind speed for peak efficiency as it was before.
You can never go home again... but I guess you can shop there.
...how something like a CVT would work for a wind turbine.
bork bork bork!
Ever read summaries? Most power generation is able to work with reasonably constant RPM's. Windmills don't have that luxury, so often are working at RPM's that are not optimum. This method (if it works) widens the optimum range.
The world is made by those who show up for the job.
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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A 100% improvement in something just means it has been improved by a factor equal to what it can already do. In other words, it's twice as efficient. If you can't understand that then you might want to think twice before posting on /. /just sayin'
CAn'T CompreHend SARcaSm?
If 1 wind turbine can output 1MW. Increasing that to 2MW would be 100% more output. It can still only be 10% efficient, but the output has doubled. 50% more efficient would be 1.5MW. Heck it could be possible to get up to 1000% more efficient (10MW), and still be at under 50% efficiency.
Maths, don't leave home with out it.
"It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt."
Just like most of the energy contained in a gallon of gasoline is not converted into forward motion, most of the energy passing by a wind turbine is not converted into electricity. It's the "low hanging fruit" in energy research. It sounds like their idea is to use more but smaller and more efficient generators that are adapted to input from variable wind speeds rather than constant input from another source, like hydroelectric dams or steam powered turbines from nuclear plants. It also says they are electronically controlled, which may eliminate the need for wasteful transfers of energy, like varying the blade pitch, mechanical clutches, etc.
Still not as effective as conservation, but unfortunately, conservation can't have an IPO, and doesn't get a lot of business press.
According to the company's website, which does have pictures of the design for anyone who is interested, this could be used with other energy sources than wind:
While this overview focuses primarily on the wind applications, VIEG Technology is expected to have a material impact on the economic viability of a wide range of renewable energy applications.
There you go. I predict this could be more applicable in tidal energy than traditional big-dam hydro, although it might be useful in small, run-of-the-river projects to make them more efficient. They might even be useful in big run-of-the-river projects, which will create over 1,000 megawatts of new electricity in the next few years in British Columbia alone.
The first thing I wondered was "what makes this design different?"
This is a nice, simple explanation of why this design can be kept efficient in a wider range of wind speeds.
Since we love to bash some of the lamer summaries, I think this one deserves a bump on the plus side.
Right, because pictures are proof. Just like the phantom console, which had pictures (http://gamedeveloper.digitalmedianet.com/articles/viewarticle.jsp?id=19801) and is totally real right now. In fact, I'm playing the invisible version as I'm typing this!
He has a point, even if 'pics' won't make much difference the vapourware will stick. There is this thing called Betz' law and it is pretty specific about how much energy you can extract from any moving medium.
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somebody is telling a stretcher here. Power goes as the cube of the wind speed. There's no point in trying to squeeze a few more percent at the low end of the range. There's just no power down there to squeeze out.
for example, at 1/2 top speed, you're getting 1/8 or 12.5% of full power at best. If it's actually 8% due to slow generator speed, no big deal. Another 4% is not worth spending much on.
That's called maximum power point tracking and is pretty old in concept and in actual use today in many thousands of wind and / or solar installations.
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I've used hydraulics. The efficiency is rather poor (remember in a wind turbine the hoses have to rotate or you need a rotating pressure joint - the thing has to face the wind, and to get good output the prop center needs to be high up meaning long hose runs.) I find it very hard indeed to believe that a PM generator with adaptive electronic control needs more maintenance than hydraulic systems, or that any cost savings outweigh the loss of efficiency over a 20 year plus lifespan. As a simple example, rail locomotives are Diesel-electric rather than Diesel-hydraulic. Hydraulics are (to the best of my knowledge) mainly useful when you want to get variable speed drives off constant speed prime movers, such as when you want the same prime mover to act as an AC generator on fixed 60 or 50Hz while also using it to power thrusters.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
So what of the things that rarely fails me is a "common sense" check on new designs, particularly when it comes to renewable energy concepts (as there are a lot of impossible inventions around).
So let's break down this design:
- Works like a normal electric motor so thus we know it works *CHECK*
- Have electronic switches to open and close a circuit, which we know works *CHECK*
- We know longer circuits have more resistance than shorter ones *CHECK*
- We know changing the number of coils in an electric generator is optimal for different levels of generation *CHECK*
So it seems to be a very good design that should work very well. Their claims of 100% more efficiency are a little over the top but may work in some locations. I think it is safe to say that most locations should see an increase in efficiency with the new design over the old one.
The way they've built their motor is also a little novel but only really amounts to a way to customize the motor for different situations and thus really isn't all too interesting in the grand scheme of things.
It's kind of like a transmission. It's actually also kind of like the reverse of the adjustable displacement engines in some vehicles.
In some cars, you have an 8-cylinder engine but can use 4, 6, or 8 cylinders at various times based on the amount of power you need to generate. It doesn't take 8 5 liters of displacement to maintain highway speeds, but getting up to them quickly may. Turning off cylinders not in use saves fuel by not burning it when it's not needed. Each cylinder only draws chemical energy to make kinetic energy as needed.
If you left all the coils engaged, you might have too much resistance to generate any electricity in light winds and too much to generate it efficiently in more moderate winds. Yet if you build a turbine specifically for only light or moderate winds, you don't get any additional power once it is maxed out.
This solution uses wind, but you can't just press down on a pedal and ask for more wind (well, you could ask, but you'd be disappointed most of the time). So what it does instead is it has a magnet-in-coil generator with separately activated coils. Each coil only draws mechanical energy to make electricity as the mechanical energy is available. The rest of the coils are left as open circuits. If there's enough wind to turn the blades with half the coils on but not all of them (or too slowly to make sense with all of them), then you just open the circuits on half the coils and the other half keep generating. Only the coils in a closed circuit generate current and present meaningful resistance to the turbine. As you have more wind, you generate more power up to the maximum. The maximum number of coils doesn't impede this turbine from generating less current when some wind is still available though, because it just disconnects the spare coils until they are needed.
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.
am i the only one worried that with a boom in windfarms, the drag on the earth's rotation will increase, slowing it and lengthening the day, making me stay at work *that* much longer?
Yes, it does have an effect. There is data showing that in wind farms the average temperature is slightly higher, and of course the wind speed is lower.
Very large wind farms will probably cause local temperature increases of 1-2 degrees centigrade. This could, of course, be mitigated by planting lots of trees all around them...
Windmills don't have that luxury, so often are working at RPM's that are not optimum. This method (if it works) widens the optimum range.
Close but not quite what they're getting at. What they're doing is increasing/decreasing the resistance to keep the windmill in the optimum RPM range over a larger range of wind speeds. So at 5 mph, the blades might spin at 20 rpm and generate 2 MW. At 15 mph, with the new system the blades still spin at 20 rpm, but now generate 5 MW. As oposed to traditional generators, where it would be spinning at 30 rpm and only generating 3 MW.
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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Wind turbines do not work that way.
No kidding!!! What do you say at this point?
I'd love to see some source on this.
I understand that a hydraulic pump and hydraulic motor coupled with two lines would be modestly simple, but the repairman going out to fix the system will probably have the same hourly/salaried rate as the repairman going out to fix the generator. Windmills have been modestly simple for hundreds of years, though. Today, the power chain looks like this:
Wind --> Blades --> Shaft --> Gearing --> Generator --> Grid
With this new system, they're hoping to get it to look like this:
Wind --> Blades --> Shaft --> Generator--> Grid
With a hydraulic system using a central generator, it would look like this:
Wind --> Blades --> Shaft --> Hydraulic Pump --> 360 Swivel --> Lines --\
Wind --> Blades --> Shaft --> Hydraulic Pump --> 360 Swivel --> Lines --> Big F'in Hydraulic Motor --> Shaft --> Generator --> Grid
Wind --> Blades --> Shaft --> Hydraulic Pump --> 360 Swivel --> Lines --/
I'd have a hard time imagining that the maintenance costs would be less with more points of failure, at least from a mechanical standpoint, not to mention the costs of cleanup due to a leak.
I'm not sure if you're being sarcastic or not. There was recently an article in the local Portland, OR news about how the windfarms that have been installed in the Columbia River Basin may actually have a detrimental impact on salmon. Apparently, some parts of the electrical grid in this part of the country are operating near peak capacity. When the wind really kicks in and pushes the grid to its limits, other parts have to lower production. In our case, this means letting a lot more water spill over the dams. This, in turn, tends to introduce way too much nitrogen into the water, which harms the fishies. Or so goes the theory.
Whoever added the tag has no clue. This IS a generator.
It generates. So loosely speaking it's a generator.
But there is a terminology distinction when you get into TYPES of things that generate. They all have coils and a field in relative motion to create the output voltage. But a "generator" creates the field with electromagnets (generally using more coils driven by an external electrical source, a side-effect of the current in the output coils, or otherwise by pulling power from the input shaft) as opposed to a "magneto" which uses permanent magnets.
For wind generators this is a significant distinction: The field coils can gobble up a lot of power - and more when the wind is lower, when you have less (or none) to spare. Paying for that up front, by shelling out for somewhat pricey permanent magnets, is (at least for small mills) far better than paying as-you-go by pulling power off the top of your output. With magnetos you get it all. Thus the recent availability of high-strength neodymium magnets has led to a revolution in magneto design.
But with magnetos you have a harder time controlling the "wild AC" from the wind-speed variation: With generators you can adjust the field to regulate them. With magnetos you're stuck with the output voltage you get, driven by the RPM. This is a problem: The power available from the wind with a given rotor size varies with the third power of the wind speed. But (assuming you don't vary the blade pitch or have a variable transmission between the turbine and the magneto) the RPM and voltage go with the first power. That means the available current goes up with the second power of wind speed and the resistive heating in the coils with the FOURTH power.
Burnout is the limit on your output. So there are a number of ways of matching a wind turbine to a load and avoiding self-destruction. Some of them work by throwing away a lot of power in high winds that it would be nice to keep.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
With magnetos the voltage goes up with the RPM. In a simple direct drive mill with no pitch adjustment the RPM (for a given efficiency) goes with the wind speed. Operating above the ideal RPM cuts your torque, too far below it also looses you torque by causing the blades to go into aerodynamic stall.
In a battery charging application there is no current, and no load torque, on the blades until the RPM is high enough that the voltage from the genny is above "cutin", the sum of the battery voltage and the diode drop. Above that wind speed the current rises, the torque resistance rises, and the RPM no longer rises as fast as the wind speed. The ratio of RPM to wind speed drops as the wind speed rises further, passing through the efficient ratio and working down toward stall and virtually complete power loss. (If the mill, wiring, and battery guts were all superconductors the mill would freewheel up to the cuting speed and then never go any higher. Due to resistance the RPM still ramps up, though more gradually than wind speed, as voltage working against resistance ramps current.)
A mill with no further way to adjust things can be "tuned" for low cutin - getting some power from low winds but stalling and losing lots of opportunity to generate high power in moderate to high winds. It can be tuned for high cutin and lots of power in storms but nothing in low and normal winds. Usually it's tuned to grab as much as practical in typical winds and lose out in low winds and storms.
A "maximum power point controller" adjusts the load to get the most out of a range of winds. Typically this consists of a "buck converer" on a mill tuned for low cutin, which lets the mill run at the efficient RPM for the wind and trades away the excess voltage for higher current, getting enough extra charging to more than pay for its own losses. It's a hunk of potentially failing electronics.
Switching coils to different current/voltage tradeoffs can do a similar variable tuning with considerably simpler circuitry and less failure risk. (A typical arrangement is delta/Y conversion of a three-phase alternator, which just about doubles the output in high winds - but causes a sudden jump in torque load on the spinning blades and a spike in current and resistive heating when it "downshifts" to delta.)
This looks like they have a LOT of coils to switch around, allowing fine enough adjustment to be more practical than delta/Y without the high-frequency electronic switching and failure modes of a buck converter.
And yes they would want to pick some small amount of power at low wind speeds (it's better than nothing) and add more coils as the wind speed rises. Power goes up with cube of wind speed but RPM, and thus magneto voltage, with the first power. So torque (produced by load currents) goes up with the square. At higher winds it's simpler to add more electromagnets dragging on the rotating permanant magnets than to increase the current in each of them with the square of the voltage rather than the first power of ohm's law.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
This is just another maximum power point controller.
Some work by using a switching regulator to change the voltage/current ratio.
Some work by switching coil arrangements on the magneto to "shift gears" for efficient operation in more than one range of wind speeds. (Delat/Y switching is an example of this, giving two "gears".)
This appears to be the second approach with a large number of "gears" in the "transmission".
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Get real; you won't see home wind turbines, at least not en masse. They have too much vibration and transmitted noise to hook up to your house plus I'm sure the neighbors might object to the aesthetics.
I'm sure most of these 223 small wind turbines are quite suitable for home use.
i'd hit it so hard, if you pulled me out you'd be the king of britain [bash.org]
A whole series of tired old canards. This post smells like industry shill to me. I'll knock over just a few, and let somebody else tackle the rest.
The biggest and lamest of the lot: "backup power will still need to be built".
What a load. Where do you think power comes from right now?! Moonbeams and happy thoughts? I'll give you a hint. We call them power plants. We have lots of them. They generate power, right now. In fact, I have this computer plugged into one at this very moment. Amazing, isn't it?
Wide deployment of windmills could allow us to avoid building other types of new power plants to handle increasing demand. Seriously wide deployment of windmills could allow us to shut down some or many coal-fired power plants. The remaining existing plants can continue to run, handling the load when wind ebbs. Extremely wide deployment, meaning continent-spanning deployment, could conceivably allow us to shut down all of the existing coal plants. The wind may not be blowing here right now, but it's probably blowing somewhere else, and it's not hard to believe that it's always blowing somewhere. The one constant of Earth's atmosphere is that it is never constant. Something is always changing, which means air is always moving.
Personally I expect there will always be some sort of non-wind non-solar base in the power grid, but I can easily imagine it being hydro and nuclear, without a single combustion-based plant in operation.
Second biggest, and still quite lame: wind power is far more expensive than other sources of power.
Economics 101: do something a lot, it gets cheaper. Mine a lot of coal? It gets really cheap. Same thing can and will happen to windmills. But this is even worse for you than it first appears. Coal plants are not ever actually cheap, no matter how many you build. Nobody builds a coal plant for less than a billion dollars, and a 600 megawatt plant costs in the neighborhood of $2 billion to build. Windmills cost roughly $1 million per megawatt. So we can build 2000 megawatts of windmills for the cost of 600 megawatts of a coal plant. And then, the source of energy is free. Coal keeps costing. Sure it may actually take all 2000 megawatts of windmills to actually produce as much power annually as a 600 megawatt coal plant, due to wind variability, but still, free wind beats not-free coal all year long. Considering that the cost per windmill will come down as more people try to get in on the market and manufacturing capacity goes up, coal loses yet again. There are extremely few organizations capable of building a multi-megawatt coal power plant, while it's downright easy to build a 2-3 megawatt windmill.
Third, negative impact on human health when people are located close enough to a wind farm.
The only worthy responses to this one are snide. We can go for the Wikipedia-esque bitchslap [Citation Needed] or we can say yeah, if you stick your head into the blade arc, it will have a negative impact on your health, ar ar ar. You choose. Either way, it sounds like crap to me, especially compared to living downwind from a coal-fired plant.
So many others, so little time. Do you even know what the word sublime means?
as far as i can tell, this technology has nothing to do with Betz' law or the theoretical efficiency of a wind turbine. in fact it has nothing to do with the design of the fan blades or rotor efficiency.
instead, the innovation here is replacing a mechanical transmission with an electric one. this allows the turbine to perform optimally under a wide range of wind speeds. this could just as easily be applied to gasoline engine power generator or other non-turbine/fluid-mechanics-related power generators.
it's like being able to switch out the transmission depending on the wind speed. we already have separate generators that operate optimally at low speeds, medium speeds, and high speeds. this is just a cheap & simple way to incorporate multiple performance ranges into a single electric transmission.
You're an idiot. Reducing our oil consumption means reducing our trade deficit, which would pretty much immediately improve our economy. Furthermore, infrastructure improvements need people to build them. Job growth will ensue.
Besides, the second something looks like it might get practical the usual suspects align against it. Hyrdo? NO! Geothermal? Already got protesters firing up over that. Wind? NIMBY! Kills birds, and so on.
Guess what? The usual suspects are you and people like you! You simultaneously blame environmentalists for hindering progress while doing the exact same thing.
Step one: We aren't about to run out of oil just yet. Putting our money into drilling will just put off the day when we have to find other sources of energy. Better just to figure out a more permanent solution now and skip the drilling. What, too reasonable for you? The only solution is to keep doing the wrong thing, but harder and more? Doesn't work in sex and it doesn't work in energy.
Step two: It's not the environmentalists that are the problem. That meme needs to die. Very few environmentalists oppose safe nuclear and alternative energies. The few that do are aren't listened to. It's the people who are more interested in pushing an ideology than seeing reasonable solutions to the problem. "drill baby drill" and all that. That said, I agree that we need to have a big program of energy infrastructure investment for the sake of the country. Better diversified than completely dependent on uranium, though.
Step three: Or, how about letting people who know that hydrogen is a stupid god damn idea make the decisions? The market is full of shysters who will spend billions to push vaporware solutions that do fuck all. Maybe the Department of Energy should have a say? Maybe spend a few tax dollars on research?
Step four: Yes, R&D is important.
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.)
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."