Using an aerostat or a kite as a lifter of a regular wind turbine, by juxtaposing proven technologies?

[PierreB]

@dougselsam

a person with wind energy experience would already know to expect extremely low performance in ambient winds, due, as you say, to the small swept area, but also due to being run backwards, and the low Reynolds number with such a small size AND being limited to the ambient windspeed. A bigger turbine with real wind turbine blades might have given better results.

This is an old discussion:

Blades for a wind turbine vs for a propeller

I measured (with a multi-meter) 9 volts at 13.7 m/s then 3 amperes at 14.4 m/s, by using a Master Airscrew GF 9x4 on a motor Mabuchi RS-380PH used as generator, at about 7100 rpm, so 85 m/s tip speed and TSR of 6 for an apparent wind of 14 m/s. I extrapolated the 7100 rpm value from the voltage (3.8 volts) obtained with a drill running at 3000 rpm, which is of course very approximate. The apparent wind speed by car was measured with an anemometer. So about an average of 27 W at 14 m/s, for a sw…

Moreover the question is not the efficiency of this propeller or another rotor, but between the same propeller or rotor in both static and crosswind flight: the last is about ten times more efficient. Listen to the difference of sound between static and crosswind flight.

@dougselsam

And yes of course Kitewinder did a decent job of demonstrating a ROTOR lifted by a kite, but did not include a “flygen” generator, but instead had to add an unnecessary additional “invention” (grandma’s clothesline) and make it far more complicated than necessary.

A “flygen” generator (slow rpm due to static flight, so high weight) + the electric cable are far heavier than the rope drive transmission and the pulley aloft. So @Kitewinder 's choice was relevant, and their AWES works.

To come back to the topic, an aerostat with 1000 kg payload capacity is extremely expensive compared to the low scale of the wind turbine aloft. Helium is very expensive, and everybody knows methane, ammonia, hydrogen, but nobody uses them.