New Generator Boosts Wind Turbine Efficiency 50% 315
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.
I wonder... (Score:5, Interesting)
...how something like a CVT would work for a wind turbine.
Re:This perpetual motion machine just keeps gettin (Score:3, Interesting)
Hydraulics are the answer (Score:1, Interesting)
Read somewhere that hydraulic-pumps up in the air on the turbine with hoses all leading to a central electric generation plant nearby brings down the maintenance cost considerably. Efficient generators are more expensive and require more skilled maintenance than hydraulic-pumps factoring in the loss of efficiency with the hydro delivery system.
Twain sez... (Score:3, Interesting)
"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.
Decent Summary, Thanks (Score:5, Interesting)
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.
Re:PICS OR GTFO (Score:5, Interesting)
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.
ridiculous, do the math (Score:2, Interesting)
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.
Good concept... (Score:4, Interesting)
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.
Re:Even less dependency on foreign oil (Score:4, Interesting)
Re:Nice work! (Score:1, Interesting)
Well, I think the whole idea has already been successfully implemented.
Here in germany, you can basically see two types of wind generators: Those with a small, water-drop-shaped housing and those with a housing that has a large disc right next to the generator blades.
AFAIK, the large disc-like housing contains coil and magnet pairs (sometimes permanent magnets, sometimes electro magnets) which essentially make the generator an inverted brushless DC generator. By varying parameters in the power converter, the shape and amount of load on these coils can be varied and therefore the generator can be used very close to the maximum power point.
I fail to see how this invention is any different from this 'inverted BLDC' concept.
Re:Climate change effect of Wind Turbines? (Score:4, Interesting)
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...
Re:Hydraulics are the answer (Score:3, Interesting)
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.
Not ridiculous. Just another way of matching. (Score:3, Interesting)
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.
Re:Even less dependency on foreign oil (Score:2, Interesting)
That engine there has the number 145, I assume that's the DB classification system. The DB class 145 is apparently called the TRAXX [wikipedia.org] by the manufacturer and used on freight trains too. Numbers starting with 1 denote electric engines.
Re:Even less dependency on foreign oil (Score:3, Interesting)
>have much larger, slower moving blades
I question this. Not because I'm against windmills: I'm not, and not because I know: I don't. A very large windmill moves at a much lower RPM than a small one, but that does not necessarily mean that the blade tip speed on the big one is lower than on the small one. On aircraft, 28" long props on KR1's, and the monster 4 meter long prop on the Corsair, both have the tip moving at about the same speed.
For efficiency, you want to have your prop moving as slowly as possible, but for maximum power generation you want to interact with as much air as possible. These guys [windpower.org] claim that most wind generators have the tips moving at about 64 m/s. So I'm saying [citation needed.]
Solving the energy problem (Score:2, Interesting)
> What do you suppose would happen if we invested that money into domestic
> energy sources like wind and natural gas?
We are about to find out. You won't like the answer I suspect.
> Job creation and economic growth perhaps?
Probably not. Not much chance of getting energy at a lower price per unit out of any of this 'alterantive energy' stuff anytime soon. Otherise it wouldn't be 'alternative.' 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.
> This is a national security issue in addition to being an environmental one.
Agree 100%, which is why I don't think this is a good time to gamble on what might be when the solution is so simple a caveman could do it and requires no hoping.
Step One: DRILL EVERYTHING that looks like it has a reasonable chance of profitable production. We have to have energy in the short term and handing money to our enemies is insane. Short term we need petro fuels. Ten years from now cars being sold today are going to be on our roads and they will need fuel.
Step Two: Execute the enviromentalists for treason if it takes it but blow out the obstacles to safe nuke plants. Build hundreds of pebble bed and other safe designs. Not in twenty to fifty years, in ten. Build like we were going to war. Or better analogy, build like we did when we were trying to beat the Russians to the moon. Ramp up the transmission system to handle the extra load. Do recycle the spent fuel, again shoot the bastards if they won't stop protesting. This IS a national security crisis and we need to start acting like it.
Step Three: Now that electricity is cheap and falling in price the government must DO NOTHING. Don't attempt to pick the winners and losers, let the market figure out whether using the cheap power to make hydrogen is the right path or whether better batteries for plug in electrics are the way to go. Perhaps it is something we haven't thought of yet that will be the most practical in the end. Make electricity cheap enough and the invisible hand will point the way.
Step Four: Now that we have at least a couple of hundred years before the Uranium supplies start running low we can move on to solving the problem once and for all by dumping R&D into fusion. When that runs out, hell that will just have to be somebody else's probem.
Re:Even less dependency on foreign oil (Score:4, Interesting)
A very large windmill moves at a much lower RPM than a small one, but that does not necessarily mean that the blade tip speed on the big one is lower than on the small one.
It's rotational velocity that I'm talking about, and which has been shown to reduce bird deaths.
Re:Solving the energy problem (Score:3, Interesting)
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.