I would estimate about 10 watts peak with a toy kite in wind force 3-4.
This is what a 0.5 m² kite would do with a wind of 6 m / s during the reel-out phase, in yo-yo (pumping) mode.
Have you roughly evaluated the duration of the 10 W peak versus the whole duration: 1/5, 1/10 or other?
I would estimate 1/3
Rather a good value. If we extrapolate with your two kites of 15 m² and 5 m², we would obtain a peak of 400 W and an average power of about 130 W for 6 m / s wind speed, so 1850 W and 620 W with 10 m / s wind speed. I remark that the optimal reel-out speed, for 10 m / s wind speed, would be 3.3 m / s, leading to a force of 560 N. Is this match your tests? I remarked you obtained a force of roughly 600 N with two 15 m² and three 5 m² kites, but I don’t know with what wind speed.
that should have been about wind force 3-4. I would also say that the values are good. At the same wind speed, I harvested about 5 watts peak with a black 300 (small wind system with blades)
It seems very low, compared to the toy kite. What was the diameter of the rotor?
1,22 Meter
there is more data here. it appears to be a good wind power plant
https://www.adfontes-elbe-weser.de/wp-content/uploads/2018/06/Kleinwindanlagen_Flyer_klein.pdf
On the curve page 2, I see about 70 W with 5 m / s wind speed, and 100 W with 6 m / s wind speed, so far above 5 W you measured. Please can you explain such a difference?
I suspect that the results from the wind tunnel are ideal for effective advertising. in reality the wind is turbulent. exactly what the open-source awe uses.
Perhaps the wind turbine was at ground level while the toy kite was in altitude?
yes there is a difference. It was on the roof of the house, but the kite was higher.
Even assuming that the location of the wind turbine is not ideal, and that the curves are theoretical, I am still amazed at the huge difference between the low efficiency of the wind turbine (by the “5 watts peak” measure or estimation you provide) compared to that of the toy kite (“10 watts peak”). Turbulence does reduce the efficiency of a wind turbine, but not to this extent.
that surprised me too. in both cases I worked without a regulator with a direct load (light bulb).
My early experiments also used light bulbs. Car headlights. As the turbine spun up, the bank of light bulbs would give a bright flash as they immediately burned out from all the power. I do not think getting a single small bulb to momentarily light up intermittently is anything to get too excited about. I’ve said this a thousand time now: there are a million ways to make SOME power from wind at SOME cost. That does not point to an economical energy solution. The idea is to produce large amounts of power at low cost.
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yes, that is exactly the goal
Related, Vortex Bladeless. Do your own research about the claims in the videos: https://youtu.be/nNp21zTeCDc?t=300
that doesn’t convince me. the strong permanent wind is very nice to see in about 7000 meters here
Of what? I’m just showing a product in a further stage of development that uses the same or similar principle. We can learn from that.
if the knowledge can also be used at a distance of 7000 meters, everything is best.
The videos above talk how to design your system so its frequency matches up with that of the wind.
That’s a different question. Can a slack, elastic, rope be used to transmit small oscillations over long distances. We’ve talked about that above and how to test it.
If I had to use this vortex shedding phenomenon, perhaps I’d try to convert it to rotation at altitude, perhaps with a reciprocating piston.