Windtronics turbine.

[zoran]

Popular way before we were all born, but not for electricity generation though! 

[dbcollen]

Reply to PM from Zoran

"Hi, do you actually own the Windtronics Turbine?"


No, I do have a 10ft danbuilt, that has made quite a bit of power. The LAWS OF PHYSICS  can't be broken. There is so little energy in light breezes that even if you wind the alternator for super low cut-in there is nothing left after conversion inefficiencies. People seem to think that just because a wind turbine is spinning that there is power being made, that is simply not the case. light winds have only enough power to make the blades turn, there is nothing left to collect, all the power in the low wind is being used to overcome friction in the bearing and aerodynamic drag on the blades.

[zoran]

1. What is a "danbuilt"?
2. Why do you say that there is little energy in light breezes? Isnt that dependant on what kind of a wind turbine one owns? I mean the blade turbines will not catch any energy in those light breezes, but the Windtronics one, is specialized in those low wind movents. Could you be judging the windtronics inefficiency based on what a diff wind turbine can do?
3. What do u mean about "conversion inefficiencies"? Please tell me more on that matter.

[dnix71]

2. The energy in the wind goes up with the cube of the wind speed. This web site has a detailed explanation for why small turbines are toys [unless you live in a very windy place or live in a place that never sees the sun]. Note that the MINIMUM assumed average wind speed here is 3.5 m/s or 11.5 feet/sec. ***There is a 400 times difference between the bottom left and upper right.***
Fixed that for you kitestrings

https://www.solacity.com/small-wind-turbine-truth/

[zoran]

dnix71 that is not what im saying, if im not mistaking that chart is for turbines with blades, the Windtronics wind turbine i do not believe that it is in that category

[dnix71]

What do blades have to do with anything? The swept area is what matters. Blade diameter is one way to measure that. Whether the mill is vertical or horizontal only two things matter, the swept area and the wind speed. If you do not think the laws of physics apply to you, then there is nothing I can do to help you.

http://windpower.generatorguide.net/wind-energy.html



There is just over 100 watts at 6 m/s available to a turbine sweeping a 1 meter circle [0.785 m2 in area]. A 2m/s wind only has about 12.6 watts available. In practice no matter how well you build your turbine or what style it is, you get about 1/3 of the available energy out if you are doing well.

http://zebu.uoregon.edu/2001/ph162/l11.html Here are some practice calculations on different mill types. Note he also assumes a 20 mph wind

[zoran]

Doesnt it matter the way the energy is produced? Either with magnets and coils (Windtronics) or a generator motor?

[joestue]

Doesnt it matter the way the energy is produced? Either with magnets and coils (Windtronics) or a generator motor?

generator motors are magnets and coils. nothing new under the sun.

[kitestrings]

There is a 400 times difference between the bottom right and upper left.

dnix, I think you may have meant to say bottom left (smallest rotor, lowest wind speed) to upper right (largest rotor, highest wind speed), and perhaps there's a portion of the chart cut-off.  I'm seeing about 300x difference.

Otherwise, I think your points are all valid.  Folks seem to want to find something that just isn't there with these small turbines, and the "new, improved, revolutionary, ..." marketing hype doesn't help reinforce physics.

~ks

[Mary B]

I smell over unity crap coming up...

[JW]

You guys have been doing good at self moderating. The replies are very well thought out and fair.   

[dnix71]

Yes, kitestrings that should have been bottom left to top right.
A 7 meter turbine at 7 m/s produces 390 times as much power as a 1 meter turbine at 3.5 m/s.

[dbcollen]

Zoran,

The energy you are trying to capture with the wind turbine IS the movement of the air, commonly known as wind. It doesn't matter what kind of turbine you are using, the ABSOLUTE MAXIMUM energy you could pull out of the wind is 59.2% of the energy moving through your swept area. If you try to extract any more it will just go around your windmill instead of through it. That is the limitations of ANY windmill.

Now lets talk about your alternator. It does not matter where the magnets and coils are, they can be a relatively small alternator on the shaft or magnets on the tips of the blades going past coils, they have the EXACT same function, and all alternators are less than 100% efficient, so there are more losses. If you match your alternator as perfectly as you can to be most efficient at low speed and capture as much of the tiny bit of energy that exists in low wind speeds. (A fraction of near nothing is even nearer nothing.) Your alternator will also be very inefficient at higher speeds and will need to be limited so it doesn't burn up, sacrificing energy at higher wind speeds. Which would have actually been useful energy.

I don't think I can explain it any simpler, you have been given lots of explanations so far, Sorry I can't help you any further.