You are the ONLY person I ve found doing systematic experiments on your ideas and coming up with results that are meaningful and to a degree, accurate. I hope to see more of these backyard inventors following suit. I love your work. I'll post some of my work as soon as i get a camera. You've inspired me.
Thank you! Amazing - you were doing actual experimentation and showing your calculations and results and didn't just wait for an extraordinarily windy day to show us something spinning, but doing nothing. This is one of the most thorough and informative videos on wind turbines I've seen. Great work!
Yay! A DIY vertical axis turbine actually producing power! 5 watts is better then the 0 watts that is produced every other video I have seen. Good job.
Finally, a home brew that actually shows power output. Too many videos of wind generators without the generator. Anyone can make something spin in the wind and then claim x output. It's nice to find the few like this one that actually have the generating portion connected, so output can be observed. The more I see and learn about small wind turbines the more I like photo voltaic. There are cloudy days but with enough panels and power storage these days are not an issue. Wind on a small scale seems like the ROI just isn't there. And being mechanical, there's a much higher chance of failure. I've had panels on my roof for over 10 years, through hail and even a nearby tornado. No issues. A turbine would be most likely destroyed itself in the tornado event. I'm not saying wind power generation is a bad thing. In certain circumstances it may be ideal. The more I see video's like this with real output, the more I turn to solar. I'll admit it would be fun to try and see just how efficient I could make a wind generator, but that's more of a hobby thing and just fun to do than serious energy generation. Thanks again for the excellent video and including the power output.
Thanks, I basically picked my initial designed based on what materials I had handy. I had read that an elliptical wing was a good place to start. Actually the whole VAWT counts for swept area. The lift type blade is supposed to generate force all the way around. Drag types only do it on the downwind side.
You are correct, a lower resistance would help, also being closer to the magnets (My stator is warped.) The 'prefect load' also depends on what the turbine can actually produce. If you pull too much current, then the turbine just stalls. One of my other videos shows the Alt I was using.
Safety First, i have used ring magnets on one of mine to act like top baerings and it works, but my turbine wiegh 45lbs. anyway, good job, but now that you started you cant stop, look at me, so far i built 14 diffrent turbines and still have 3 unique ideas that i need to biuld. keep up the good work.
You might check out the Lenz2 blade. It's fairly simple and many people have good luck with it. My alt is one steel plate with magnets and coils on the other side. It's not very efficient and next time I'll go with magnets on both sides of the coils, even though its more dangerous to make.
Correct. The tip speed ratio being greater than 1 proves that. However the efficiency was pretty good considering the errors in the surfaces of the wings which are quite visible at 0:20 on in. I do like the elliptical wings because of the relative ease of construction. I think I'll try out this design and add a few tricks I've been thinking of to see what I can get out of it. I have a few ideas what I'll make it out of.
@Windroseism dims are on one of the first comments above. It did self start by rocking back and forth until it took off. The airfoil is a simple ellipse.
Yes, I have thought of it. But the computer systems I used for this are gone. All the software versions have changed, etc. It would be a lot of work to get this running again. I have other things in my life that are taking my time. (House maintenance, kids, etc.)
Eventually I will generate some power, but this is just a small test turbine to experiment with wing shapes. (The wings can be replaced by removing a few bolts.) Once I get it right, I might make a bigger one.
@Mrinfoone The wings are simple ellipses 9" x 1/2" x 24" and they are mounted 8" from the center at an angle of 0 degrees measured at the center of the wing.
Mass would help keep the speed (and power) more steady in a gusty wind, but on average it shouldn't make any difference. (Assuming it's not so heavy that the bearings are stressed.) I made this light so that if it flew apart, it wouldn't kill anyone or damage my house.
For this design I would build 4-blade, not 3-blade turbine. And I would secure it from 2 points of axle, for not losing energy caused by vibration and gyroscopic friction braking. And never expect to get 100% of wind impact energy out of your turbine. I would expect 500 W medium wind to turn 350 W generator (70%) and it should work at lower wind speeds also. The air density for average temperature where I live is about +5 C, so air density is for this temperature about 1,27 and for +10 C 1,25. 5/4 is pretty good to simplify calculations.
Also since I did this turbine, I've done lots of computer simulations and calculations on this design. It turns out that it's very easy to stall it with a resistive load, and my measurement system may have been too crude to actually find the peak powerpoint. (The peak power point and the point where it stalls to very little power are very close.)
@Zypkin I'll admit the alternator is poor, but it was enough to bring the turbine to a crawl. I was only using one phase to test which was 46 ohms. Had the alt been the real problem, the turbine would have continued at nearly full speed. I was hoping to have to use all 3 phases to load the turbine, but it was so weak it wasn't necessary.
@Zypkin You are correct. That alt will never produce any serious power. It was my first try, and I didn't run through the equations before I made it. Still is has been good enough to test all my small turbines so far. (I haven't had one that could overpower it.)
Dorry Dean, meant to reply and accidentally removed your last comment. UA-cam gives no second chances! Anyway, voltage is all in the speed of the turbine, size of the magnets, and the number of turns in the coils. I'm using pretty big magnets, and about 175 turns * 3 coils per phase.
You did good. Some power better than no power. Adjust size to harvest something.and be a winner. Moley magnets are best though costly. Keep it up. Good show.
@215alessio That's true if the the turbine has the power to push the alt to that point. In my case the turbine was too weak so the peak power point would be more determined by the characteristics of the turbine and not the alt.
Nice job, sound engineering, well explained. I knew the electrical part being a ham as well as eletronics geek and rider of 450w ebike but didn't know the aronautical parts. I'm a big fan of VAWT esp low speed / high torque ones. I loved your comment going in about all these spinny things on youtube and the like and "do they make any power?". As a friend said about Sterling engines, ever see one doing any work? Or just spinning? I think an odd number of vanes is a plus and larger radius would slow it down but increase torque and you might be able to vary that to better match the generator. Still 5w from somthing that looks like $20 worth of parts and a PM motor is a lot more cost effective than a 5w solar panel from Harbor Freight! For very small energy production needs like to float charge / maintain a deep cycle, 5w is not that bad. Adding 5-25w of solar to make up for daytime and no wind would be nice and the wind turbine probablly spins at night. As an off-grid guy I met who runs wind and PV said, when it's sunny it may not be windy but when it's not sunny there's usually wind! 73 all de n3glv
Greetings, thanks for going a little deeper than most. There's more to it than 'it produces 'x' number of volts'! If I remember correctly, the perfect load would be equal to the resistance of the alt coils for maximum power transfer. Are you using a homemade alt? To get better efficiency, I believe you need to lower the alt coil resistance. In any case, I appreciate your efforts here. I live in the city and limited to VAWT's and I'm just starting to seriously consider alternative power.
i have a motor so im not going to bust up and count coils but its 7 volts at 15 mph, i live in Nashville tennessee and we dont get much wind but its an experamentel model for me if you go to my profile you will see a picture of the motor with the blades on, thanks and are u going to make another video about your wind turbine? thanks
Some things to consider. First your video is one of the most thorough that I've seen. You document your work well. I was wondering how you derived your measurements (8", 9", 1/2", 2'). Also where did the idea for elliptical wing cross sections come from? Your efficiency measurement I think needs adjustment. Only 1/2 of the VAWT counts for swept area, so the .25m becomes .125m. Power goes from 40 to 20watts @100%. 25% of 20 is 5 watts. And what did your turbine produce? 5 watts.
I go into more detail on that alternator in one of the other videos. Basically the magnets are on a steel plate and the coils are just backed by wood. Because of the warp in the stator it's not very efficient. Magnets on both sides is probably a better way to do it, but more complex and more dangerous. There is no cogging in this alt.
Use some gripper primer by Glidden to hold down fiberglass screen over the whole thing and it'll make it a lot stronger but that's this is a great idea especially to be a quiet windmill I'm thinking about something to bring with me on my van that I can put up for a little extra power
Very nice video. Thank you very much. I am about to start my own prototype of VAWT and I wanted to know what kind of alternator you used? As for the wings, I also don´t know what kind of profile I should use. But thank you already for the very good description video!
@sjh7132 ...46ohm looks to me a huge number for a device supposed to make power (let's be clear, it's not Urs only... it's a common range for coreless axial flux machines I saw around). As a matter of fact commercial generators have internal impedance less than 1ohm... and that's because you have to get the power out of the machine and not waste it in heat :) Anyway, I'm just tyring to help... I'm working on a ferromagnetic core axial machine, I hope I'll post my results within the summer.
Hi, I am a High School Math teacher in New York City. Would it be possilbe to see a video of how you built the turbine's blades. I have several projects including building a wind turbine in class by dfferent groups of students ( one group will build the stator, the other he turbine and another will do the calculations ) Your viedo is very instructive. Would you please made a viedo on how to shape and build the blades? Thanks.
I used the full area (height * diameter) because this type of blade should create power all the way around. (except for directly into and with the wind)
@ldelossant Those blades I hot wire cut by putting current through a wire to heat it up and pulling it through the foam. Later I built a machine to do it. (It's shown in one of my later videos). You might want to consider doing a HAWT because you can just cut those blades from PVC pipe. (in my next video) Also you might want to check out the vawts dot net site.
@walkertongdee In this video the wing is just an ellipse (squashed circle) and it's mounted with a mount angle of 0 degrees. (aoa generally is relative to the wind, which changes depending on where the wing is in it's rotation.) In other videos I use air foils. Many people build their turbines so they can adjust the angle, I never have.
@Zypkin ...a good generator should blow the coils if you short it... meaning its own impedance shall be so low to generate lot of current. To get a low impedance you need to use less copper (less turns in your coils) but since you shall keep the voltage high you must definitely reduce the air-gap stator/rotor and improve the overall design of the generator :)))
I hope you understand that the power equation is the power available in the wind, not the power you can produce. You need to add in Betz limit (16/27 or 0.5926) to find the max power you can actually achieve. So really, your turbine should be able to optimally produce around 25 watts. With efficiency factored in, 50% efficiency will lead to maybe 12 watts. Then there is inherent loss from the circuitry, so you are really looking at closer to 10 watts. Just so you know. Good video and nice idea.
@0:15 how does it have power when blades r symmetric and haven't angle attack and not airfoil. please explain. and thanks for video and all reply. congratulations!
Yes, I was a little naive when I made this first video. :-) Although when I calculate efficiency of my turbines, I use % of the power in the wind, not of the Betz limit. So the highest I could ever see is 59%. Its a little misleading to calculate based on the Betz limit, isn't it? A good turbine is 30% efficient so 12 watts could be reasonable.
Just breeze here , but I had a little sailboat, and it put out about 2 hp, so a windmill of for sails should be cheap and powerful, also an old gas moter would be good for berings and pump actions.
@craftmatic2 Solar is good. But solar only works during the day. It's also not ideal in places where you get less sun. A combination of wind and solar would be better. Where I live it's frequently cloudy. So I am looking into wind generators to go along with solar.
@sjh7132 ...right... but this wouldnt work because would also increase the thickness of the coil which, being coreless, would lose most of the magnetic field :)
the best output power is when the amps equal the voltage forming a perfect square in the voltafe amps graphic respecting the max output amperage of your coils ofcourse
+MrPSCHEUR It rotates equally well in both directions and it's kind of a random thing. Since the output is AC it doesn't make any difference electrically.
@wordpresswidget Yes I rounded. I think at the time i was estimating in my head and approximated 6.7 as 7. Yes, breaking Betz is impossible, that's what I'm saying. If I take the measured power of some lenz2 turbines and use the formula for area that you pointed me to, it would sometimes break Betz. If i use the full area (d * h) Its about 40% efficient.
I waw wondering if the wings are an airfoil shape like an airplane wing, I cant really see them and if so how did you choose the angle of attack? Would it be a good idea to be able to rotate the wings to set the attack angle? Please respond..
@Shalek That's only a problem for pure drag type turbines, and in that case a ramp or series of ramps (so it handles all wind directions) helps. Most modern blades use lift and still drive forward on most of the upwind side. See my video about the lenz blade Simulation watch?v=Mk49ZgBTX5A
Maybe your area don't be 0,25 m2. I dont know how can be calculated exactly but i think it could be less because the wind only push a half side of the turbine and the other half oppose to that pushing. Thanks for your good video, it's interesting to learn to me!
it doesn't matter, this is how turbine area is calculated so it is the same thing for all kinds of turbines and if your turbine is wasting some of it, it's accounted in turbine efficiency (for example savonius turbine where only half of area do actual work have low efficiency ~20% at most)
sjh7132 You should take the knowledge from big wind turbines that use magnets to 'break' the speed down. It is not about how fast it spins to generate electricity after all. But breaking the RPM down a notch using Electrical magnets, you can potentially produce more Watts since it produces more workload/Ampere for ya. Hard to explain since I am not English Primary language but I learned most of this stuff back in school when I studied to become electrician.
Question: Does your "swept area" calculations include the entire area of the rotor...or just the windward side producing power? Obviously the rotors going back into the wind would not only not be producing power, but would also be taking power via drag. I think that, and an unrealistic "swept area" calculation might explain your low efficiency numbers...
+Jc Knight At first that seems obvious, but it's wrong. The blade coming up wind actually does generate power. It's just like a sail boat sailing tacking and sailing up wind at an angle. The only place the blade doesn't generate power is when it's almost straight up wind and down wind. The swept area is the entire area of the rotor.
Sorry so late in reply. In order for the upwind sail to be generating net positive thrust on the axle, the blade would have to be constantly changing it's blade angle through it's upwind sweep. Just like a retreating Helicopter blade would have to increase it's pitch (via the swashplate) to maintain net lift on that side of the rotor. (I design airfoils and wings) Did i miss something in the mechanism that accounted for that? At some point the airfoil/angle of attack to the relative wind is going to generate thrust, but if the advancing airfoil can't constantly change it's angle of attack it's going to be creating a net drag on the design. The analogy of the sailboat works because the sailor constantly changes it's angle of attack depending on the position of the relative wind, and produces thrust approximately 45 degrees between the track of the boat and the sail position. How does this VAWT do that?
There are VAWTs that do what you say, with the wing adjusting as it goes around. See SB&K or SHARP vawt. In my case the wing is fixed. But since it's running faster than the speed of the wind, the angle of attack varies through a limited angle and the wing can generate lift most of the way around. The biggest problem is getting started since when the wing is moving slowly the angle of attack goes through all 360 degrees.
I think efficiency is way overvalued as a measure of wind turbine performance. (power produced / money spent) is the figure to be maximised. A cheap and gale-resistant design will beat an efficient one, its just a matter of scaling it up in size untill it produces the power output required.
I agree, but you probably need to factor in the cost of keeping it running into the equation. Also if you live in a place where your neighbors don't want to see a turbine, more power from a smaller turbine is somewhat important.
@wordpresswidget The poster claiming the 2/3rds factor has made many assumptions. The fact that he made one or two VAWTs and used a little calc doesn't make him an expert. There are many other experts that disagree. In fact we've seen VAWTs that would be breaking Betz if you applied that 2/3rds factor to the area.
Ideally you'd measure the curves for the performance of the turbine, so you'd know power vs RPM for different wind speeds. Then you can design and alt if you know the strength and size of the magnets and the resistance of the copper that will match it. Getting the turbine measurements is the hard part. You are also safe, if you just over design the alt and make it bigger than it needs to be. It will be very efficient, but it will cost more because of the magnets and copper wire.
con las resistencias hara usted un divisor de voltaje¿¿¿¿¿¿¿¿ perdon no hablo ingles, es una idea que yo querria usar, puede explicar para traducir.......gracias
Your power problem is not in the turbine... it's in the generator! You are trying to get 20W out of a generator which resistance is 46ohm and spinning at 25V. Now, you dont specify which Tension and Impedance you measured (phase or line), however given that P=V^2/R if you short the generator (no load) you have 25*25/46 = 13.6W ...it's the best you can get: with no load... adding any load would just increase the overall impedance thus reducing the current and consequently the power.
You are the ONLY person I ve found doing systematic experiments on your ideas and coming up with results that are meaningful and to a degree, accurate. I hope to see more of these backyard inventors following suit. I love your work. I'll post some of my work as soon as i get a camera. You've inspired me.
Thank you! Amazing - you were doing actual experimentation and showing your calculations and results and didn't just wait for an extraordinarily windy day to show us something spinning, but doing nothing. This is one of the most thorough and informative videos on wind turbines I've seen. Great work!
The best video and explanation I've seen on here yet. Real Calculations for a real generator, and a good conclusion. Well done sir.
Yay! A DIY vertical axis turbine actually producing power! 5 watts is better then the 0 watts that is produced every other video I have seen. Good job.
Most well done video on VAWT, I have found so far on UA-cam.
A realistic analysis and approach, which makes this one of the best video.
Yes if you're an electrical engineer. I'm not and cant do this same testing at my house, lol.
@@diyoregonnowtexas9202 You're going to need those meters to figure out your full output at some point.
I finally found a real Engineer on the net. Good experiment thanks for including the formulas.
Finally, a home brew that actually shows power output. Too many videos of wind generators without the generator. Anyone can make something spin in the wind and then claim x output. It's nice to find the few like this one that actually have the generating portion connected, so output can be observed. The more I see and learn about small wind turbines the more I like photo voltaic. There are cloudy days but with enough panels and power storage these days are not an issue. Wind on a small scale seems like the ROI just isn't there. And being mechanical, there's a much higher chance of failure. I've had panels on my roof for over 10 years, through hail and even a nearby tornado. No issues. A turbine would be most likely destroyed itself in the tornado event. I'm not saying wind power generation is a bad thing. In certain circumstances it may be ideal. The more I see video's like this with real output, the more I turn to solar. I'll admit it would be fun to try and see just how efficient I could make a wind generator, but that's more of a hobby thing and just fun to do than serious energy generation. Thanks again for the excellent video and including the power output.
Thanks, someone who actually tests their turbine. So many youtube videos say "of course it's efficient, it just goes like crazy."
Thanks, I basically picked my initial designed based on what materials I had handy. I had read that an elliptical wing was a good place to start.
Actually the whole VAWT counts for swept area. The lift type blade is supposed to generate force all the way around. Drag types only do it on the downwind side.
Love your approach. Your video is very complete. I am still with optimizing, scaleing up of the turbine. Thanks for sharing this.
You are correct, a lower resistance would help, also being closer to the magnets (My stator is warped.) The 'prefect load' also depends on what the turbine can actually produce. If you pull too much current, then the turbine just stalls. One of my other videos shows the Alt I was using.
Safety First, i have used ring magnets on one of mine to act like top baerings and it works, but my turbine wiegh 45lbs.
anyway, good job, but now that you started you cant stop, look at me, so far i built 14 diffrent turbines and still have 3 unique ideas that i need to biuld.
keep up the good work.
You might check out the Lenz2 blade. It's fairly simple and many people have good luck with it.
My alt is one steel plate with magnets and coils on the other side. It's not very efficient and next time I'll go with magnets on both sides of the coils, even though its more dangerous to make.
Correct. The tip speed ratio being greater than 1 proves that. However the efficiency was pretty good considering the errors in the surfaces of the wings which are quite visible at 0:20 on in. I do like the elliptical wings because of the relative ease of construction. I think I'll try out this design and add a few tricks I've been thinking of to see what I can get out of it. I have a few ideas what I'll make it out of.
Coming from a student testing wind turbines, this is a great video.
Thank you. One of the best turbine videos I have been able to find. Good info.
Thanks for the offer. I don't have anything big currently planned but I'll keep you in mind.
@Windroseism dims are on one of the first comments above. It did self start by rocking back and forth until it took off. The airfoil is a simple ellipse.
Genius man, thank you very much for your detailed description of your experiment. Thank you!
Have you thought of redoing your evolution design with the proper viscosity and try that out?
That would be a great idea.
Author, please address this question
Yes, I have thought of it. But the computer systems I used for this are gone. All the software versions have changed, etc. It would be a lot of work to get this running again. I have other things in my life that are taking my time. (House maintenance, kids, etc.)
Just found this channel, this would be extremely interesting .
Post the code somewhere,so someone else can fix it
Eventually I will generate some power, but this is just a small test turbine to experiment with wing shapes. (The wings can be replaced by removing a few bolts.) Once I get it right, I might make a bigger one.
@Mrinfoone The wings are simple ellipses 9" x 1/2" x 24" and they are mounted 8" from the center at an angle of 0 degrees measured at the center of the wing.
Mass would help keep the speed (and power) more steady in a gusty wind, but on average it shouldn't make any difference. (Assuming it's not so heavy that the bearings are stressed.)
I made this light so that if it flew apart, it wouldn't kill anyone or damage my house.
Impressively thorough. Thank you.
Thats incredible. Most efficient speed. Wow
For this design I would build 4-blade, not 3-blade turbine. And I would secure it from 2 points of axle, for not losing energy caused by vibration and gyroscopic friction braking. And never expect to get 100% of wind impact energy out of your turbine. I would expect 500 W medium wind to turn 350 W generator (70%) and it should work at lower wind speeds also. The air density for average temperature where I live is about +5 C, so air density is for this temperature about 1,27 and for +10 C 1,25. 5/4 is pretty good to simplify calculations.
Also since I did this turbine, I've done lots of computer simulations and calculations on this design. It turns out that it's very easy to stall it with a resistive load, and my measurement system may have been too crude to actually find the peak powerpoint. (The peak power point and the point where it stalls to very little power are very close.)
You are objective, with super math skills, you could have been a pharmacist, maybe you are. Keep doing good things, thank you, Gene the zman
@Zypkin
I'll admit the alternator is poor, but it was enough to bring the turbine to a crawl. I was only using one phase to test which was 46 ohms. Had the alt been the real problem, the turbine would have continued at nearly full speed. I was hoping to have to use all 3 phases to load the turbine, but it was so weak it wasn't necessary.
This is really good video. I've seen other videos with other designs claiming 1kw of power
@Zypkin
You are correct. That alt will never produce any serious power. It was my first try, and I didn't run through the equations before I made it. Still is has been good enough to test all my small turbines so far. (I haven't had one that could overpower it.)
Dorry Dean, meant to reply and accidentally removed your last comment. UA-cam gives no second chances! Anyway, voltage is all in the speed of the turbine, size of the magnets, and the number of turns in the coils. I'm using pretty big magnets, and about 175 turns * 3 coils per phase.
excellent video, and explanations.
20 stars.
MUDDy
You did good. Some power better than no power. Adjust size to harvest something.and be a winner. Moley magnets are best though costly. Keep it up. Good show.
@215alessio That's true if the the turbine has the power to push the alt to that point. In my case the turbine was too weak so the peak power point would be more determined by the characteristics of the turbine and not the alt.
Nice job, sound engineering, well explained. I knew the electrical part being a ham as well
as eletronics geek and rider of 450w ebike but didn't know the aronautical parts. I'm a big
fan of VAWT esp low speed / high torque ones. I loved your comment going in about all
these spinny things on youtube and the like and "do they make any power?".
As a friend said about Sterling engines, ever see one doing any work? Or just spinning?
I think an odd number of vanes is a plus and larger radius would slow it down but increase
torque and you might be able to vary that to better match the generator. Still 5w from
somthing that looks like $20 worth of parts and a PM motor is a lot more cost effective
than a 5w solar panel from Harbor Freight! For very small energy production needs like
to float charge / maintain a deep cycle, 5w is not that bad. Adding 5-25w of solar to make
up for daytime and no wind would be nice and the wind turbine probablly spins at night.
As an off-grid guy I met who runs wind and PV said, when it's sunny it may not be windy
but when it's not sunny there's usually wind!
73 all de n3glv
Greetings, thanks for going a little deeper than most. There's more to it than 'it produces 'x' number of volts'! If I remember correctly, the perfect load would be equal to the resistance of the alt coils for maximum power transfer. Are you using a homemade alt? To get better efficiency, I believe you need to lower the alt coil resistance. In any case, I appreciate your efforts here. I live in the city and limited to VAWT's and I'm just starting to seriously consider alternative power.
i have a motor so im not going to bust up and count coils but its 7 volts at 15 mph, i live in Nashville tennessee and we dont get much wind but its an experamentel model for me if you go to my profile you will see a picture of the motor with the blades on, thanks and are u going to make another video about your wind turbine? thanks
Some things to consider. First your video is one of the most thorough that I've seen. You document your work well.
I was wondering how you derived your measurements (8", 9", 1/2", 2'). Also where did the idea for elliptical wing cross sections come from?
Your efficiency measurement I think needs adjustment. Only 1/2 of the VAWT counts for swept area, so the .25m becomes .125m. Power goes from 40 to 20watts @100%. 25% of 20 is 5 watts. And what did your turbine produce? 5 watts.
I go into more detail on that alternator in one of the other videos. Basically the magnets are on a steel plate and the coils are just backed by wood. Because of the warp in the stator it's not very efficient. Magnets on both sides is probably a better way to do it, but more complex and more dangerous. There is no cogging in this alt.
Thanks! i want to try to make one myself now :D very inspiring
Use some gripper primer by Glidden to hold down fiberglass screen over the whole thing and it'll make it a lot stronger but that's this is a great idea especially to be a quiet windmill I'm thinking about something to bring with me on my van that I can put up for a little extra power
very nice setup! likr the anemometer, are u going to make any electricty out of it?
Very nice video. Thank you very much.
I am about to start my own prototype of VAWT and I wanted to know what kind of alternator you used? As for the wings, I also don´t know what kind of profile I should use.
But thank you already for the very good description video!
not bad vid...alot of info...you have a great view. good work.
dont you think Mass has anything to do with it??
@danie1murphy
Thanks. Yes it seems that many people don't realize that power and speed are two different things.
torque
@sjh7132 ...46ohm looks to me a huge number for a device supposed to make power (let's be clear, it's not Urs only... it's a common range for coreless axial flux machines I saw around). As a matter of fact commercial generators have internal impedance less than 1ohm... and that's because you have to get the power out of the machine and not waste it in heat :)
Anyway, I'm just tyring to help... I'm working on a ferromagnetic core axial machine, I hope I'll post my results within the summer.
Once they start moving and you add the vector of the wind with the vector of the apparent wind from the movement, there is a non-zero angle of attack.
Make a jellyfish-bladed turbine.
Hi, I am a High School Math teacher in New York City. Would it be possilbe to see a video of how you built the turbine's blades. I have several projects including building a wind turbine in class by dfferent groups of students ( one group will build the stator, the other he turbine and another will do the calculations ) Your viedo is very instructive. Would you please made a viedo on how to shape and build the blades? Thanks.
Umm the sweep area u talk of? Is it the hight * breadth of the blades, or the circle they scribe on the ground ?
I used the full area (height * diameter) because this type of blade should create power all the way around. (except for directly into and with the wind)
@ldelossant
Those blades I hot wire cut by putting current through a wire to heat it up and pulling it through the foam. Later I built a machine to do it. (It's shown in one of my later videos). You might want to consider doing a HAWT because you can just cut those blades from PVC pipe. (in my next video) Also you might want to check out the vawts dot net site.
@craftmatic2
Or just a plain old solar panel. I have 1000 watts of those running already. I'm just exploring other options.
Were you able to make something that had better output?
@walkertongdee
In this video the wing is just an ellipse (squashed circle) and it's mounted with a mount angle of 0 degrees. (aoa generally is relative to the wind, which changes depending on where the wing is in it's rotation.) In other videos I use air foils. Many people build their turbines so they can adjust the angle, I never have.
@Zypkin ...a good generator should blow the coils if you short it... meaning its own impedance shall be so low to generate lot of current.
To get a low impedance you need to use less copper (less turns in your coils) but since you shall keep the voltage high you must definitely reduce the air-gap stator/rotor and improve the overall design of the generator :)))
great work, keep up researching! I need to draw charts like you showed on the video for my projects, what program did you use to draw them?
+lego getriebe I think it was OpenOffice Calc (a spread sheet program. like Excel)
sjh7132 OK, thanks! I tried with I think Microsoft exel and it didn't work for me :(
I think the problem is not your turbine, is in your generator. hope you improved it
how are the wires hooked up & what are they hooked too?
I hope you understand that the power equation is the power available in the wind, not the power you can produce. You need to add in Betz limit (16/27 or 0.5926) to find the max power you can actually achieve. So really, your turbine should be able to optimally produce around 25 watts. With efficiency factored in, 50% efficiency will lead to maybe 12 watts. Then there is inherent loss from the circuitry, so you are really looking at closer to 10 watts. Just so you know. Good video and nice idea.
@0:15 how does it have power when blades r symmetric and haven't angle attack and not airfoil. please explain.
and thanks for video and all reply.
congratulations!
How did you build the generator?? it looks like a very stable design!
Yes, I was a little naive when I made this first video. :-) Although when I calculate efficiency of my turbines, I use % of the power in the wind, not of the Betz limit. So the highest I could ever see is 59%. Its a little misleading to calculate based on the Betz limit, isn't it? A good turbine is 30% efficient so 12 watts could be reasonable.
Great job
I like it, very interesting !!
Just breeze here , but I had a little sailboat, and it put out about 2 hp, so a windmill of for sails should be cheap and powerful, also an old gas moter would be good for berings and pump actions.
@Zypkin
Or use more copper in terms of thicker wire.
@craftmatic2 Solar is good. But solar only works during the day. It's also not ideal in places where you get less sun. A combination of wind and solar would be better.
Where I live it's frequently cloudy. So I am looking into wind generators to go along with solar.
No, area for a VAWT is the area seen from the side, so it's diameter x height.
Where did you find the money for all that equipment.If I had that i finished my project.good luck dude
@ed4ed
Those are high tension electric wires with the sun glinting off of them. Sheesh, I don't live on a rocket test range or anything like that.
@sjh7132 ...right... but this wouldnt work because would also increase the thickness of the coil which, being coreless, would lose most of the magnetic field :)
Nice Job !!!
the best output power is when the amps equal the voltage forming a perfect square in the voltafe amps graphic
respecting the max output amperage of your coils ofcourse
I am curious, what would happen if you introduced gears with high ratios? I believe it would possibly modify the speed of the alternator
Many thanks. What that determines the rotation direction?
+MrPSCHEUR
It rotates equally well in both directions and it's kind of a random thing. Since the output is AC it doesn't make any difference electrically.
aww, i thought they were Jellyfish Blades xD
also meter is with a small "m" so is kilo with a small "k".
Also came here for that!
Very nice
hey steve , have you given up on wind?
@wordpresswidget Yes I rounded. I think at the time i was estimating in my head and approximated 6.7 as 7.
Yes, breaking Betz is impossible, that's what I'm saying. If I take the measured power of some lenz2 turbines and use the formula for area that you pointed me to, it would sometimes break Betz. If i use the full area (d * h) Its about 40% efficient.
Thanks, I'm an Electrical Engineer. I never considered pharmacist. :-)
I waw wondering if the wings are an airfoil shape like an airplane wing, I cant really see them and if so how did you choose the angle of attack? Would it be a good idea to be able to rotate the wings to set the attack angle? Please respond..
@Shalek
That's only a problem for pure drag type turbines, and in that case a ramp or series of ramps (so it handles all wind directions) helps. Most modern blades use lift and still drive forward on most of the upwind side. See my video about the lenz blade Simulation watch?v=Mk49ZgBTX5A
@1:32 did you use Area=circumfrence*height?
Maybe your area don't be 0,25 m2. I dont know how can be calculated exactly but i think it could be less because the wind only push a half side of the turbine and the other half oppose to that pushing. Thanks for your good video, it's interesting to learn to me!
it doesn't matter, this is how turbine area is calculated so it is the same thing for all kinds of turbines and if your turbine is wasting some of it, it's accounted in turbine efficiency (for example savonius turbine where only half of area do actual work have low efficiency ~20% at most)
I always wondering which is the best type of generator for small scale wind turbines?..alternators...brushless motors...?
Muito bom seu trabalho,preciso fazer esse calculo para o meu gerador de ventilador de teto.
Carlos Leme
Você pode obter uma eficiência menor sobre a turbina de vento do ventilador de teto. Ele ele, deixe-me saber o que encontrar Carlos.
MUDDy
***** Obrigado
sjh7132
You should take the knowledge from big wind turbines that use magnets to 'break' the speed down. It is not about how fast it spins to generate electricity after all. But breaking the RPM down a notch using Electrical magnets, you can potentially produce more Watts since it produces more workload/Ampere for ya. Hard to explain since I am not English Primary language but I learned most of this stuff back in school when I studied to become electrician.
+Helveteshit
vi su comentaro y estoy interesado en el tema, me intereso su planteamiento, su primera lengua sera español¿¿¿¿¿¿
Jose Barra
Sorry, I am Swedish, not Spanish/Portuguese.
Question: Does your "swept area" calculations include the entire area of the rotor...or just the windward side producing power?
Obviously the rotors going back into the wind would not only not be producing power, but would also be taking power via drag. I think that, and an unrealistic "swept area" calculation might explain your low efficiency numbers...
+Jc Knight At first that seems obvious, but it's wrong. The blade coming up wind actually does generate power. It's just like a sail boat sailing tacking and sailing up wind at an angle. The only place the blade doesn't generate power is when it's almost straight up wind and down wind.
The swept area is the entire area of the rotor.
*"It's just like a sail boat sailing tacking and sailing up wind at an angle."*
Really? It doesn't make sense to me.
Sorry so late in reply.
In order for the upwind sail to be generating net positive thrust on the axle, the blade would have to be constantly changing it's blade angle through it's upwind sweep. Just like a retreating Helicopter blade would have to increase it's pitch (via the swashplate) to maintain net lift on that side of the rotor. (I design airfoils and wings)
Did i miss something in the mechanism that accounted for that? At some point the airfoil/angle of attack to the relative wind is going to generate thrust, but if the advancing airfoil can't constantly change it's angle of attack it's going to be creating a net drag on the design.
The analogy of the sailboat works because the sailor constantly changes it's angle of attack depending on the position of the relative wind, and produces thrust approximately 45 degrees between the track of the boat and the sail position. How does this VAWT do that?
There are VAWTs that do what you say, with the wing adjusting as it goes around. See SB&K or SHARP vawt. In my case the wing is fixed. But since it's running faster than the speed of the wind, the angle of attack varies through a limited angle and the wing can generate lift most of the way around. The biggest problem is getting started since when the wing is moving slowly the angle of attack goes through all 360 degrees.
I think efficiency is way overvalued as a measure of wind turbine performance.
(power produced / money spent) is the figure to be maximised.
A cheap and gale-resistant design will beat an efficient one, its just a matter of scaling it up in size untill it produces the power output required.
I agree, but you probably need to factor in the cost of keeping it running into the equation. Also if you live in a place where your neighbors don't want to see a turbine, more power from a smaller turbine is somewhat important.
@HeavyDemir
It's Height * Diameter
can you send me the dimensions diagram off the wings and or diagrams? so i could build one thanks
@wordpresswidget
The poster claiming the 2/3rds factor has made many assumptions. The fact that he made one or two VAWTs and used a little calc doesn't make him an expert. There are many other experts that disagree. In fact we've seen VAWTs that would be breaking Betz if you applied that 2/3rds factor to the area.
So how does one best match their turbine to their alternator (or vs versa)?
Ideally you'd measure the curves for the performance of the turbine, so you'd know power vs RPM for different wind speeds. Then you can design and alt if you know the strength and size of the magnets and the resistance of the copper that will match it. Getting the turbine measurements is the hard part.
You are also safe, if you just over design the alt and make it bigger than it needs to be. It will be very efficient, but it will cost more because of the magnets and copper wire.
How do you wire the axel to te alternator?
There are only magnets on the spinning part of the turbine. All the wiring (coils) are stationary. The wires just come out the side.
con las resistencias hara usted un divisor de voltaje¿¿¿¿¿¿¿¿ perdon no hablo ingles,
es una idea que yo querria usar, puede explicar para traducir.......gracias
thanks for your reply
Could you explain .... in English ... I translated
Use of resistors to measure
Voltage or amperage?
I want to do the same as you
@TheTwistedGypsy
i think you are mistaking the sun's reflection off of some high tension electric wires for chem trails.
Your power problem is not in the turbine... it's in the generator!
You are trying to get 20W out of a generator which resistance is 46ohm and spinning at 25V.
Now, you dont specify which Tension and Impedance you measured (phase or line), however given that P=V^2/R if you short the generator (no load) you have 25*25/46 = 13.6W ...it's the best you can get: with no load... adding any load would just increase the overall impedance thus reducing the current and consequently the power.