It’s really hard to tell even with our current knowledge.
I think the first big question to answer is how the blade mass would scale. 3th order, 2th order or something in between?
Even if the mass of the total system scaled in the 3th order, then it would still be a bit lighter than current 10MW turbines. Obviously the overhung rotor will have a huge bending force, but probably less than the bending force of a tower of a turbine today.
That said I’m actually still happy with the design even if it didn’t scale past 10-100 kW. I still believe there is a potential for systems of this size to make a sizeable difference.
Or as you say on the downward end of the boom. Would requre swivels and large vanes tough or counterrotating blades.
Also power transfer becomes an issue of course. Would need brushes to prevent torsion of the cable.
You’re probably aware of @Kitewinderhttps://kitewinder.fr/ a groundgen system. Maybe it could have a more tensile blade structure like the windcatcher.
The advantage would be stronger winds at higher altitudes.
This turbine can be implemented as it is like @aokholm indicates.
But also some variants can be studied, benefiting from its high swept area / weight ratio: static flygen mode with this turbine carried by a kite as indicated above by @Tom; then crosswind flygen mode as for my old FlygenKite. I don’t think there is a problem of torsion of the electric cable since the generator is fixed at the main gear periphery by a fixed arm. Said main gear also could perhaps have lines towards the node in order to improve its stability and mitigate the cantilever effect on it due to the wind force on the rotor.
I see another variant I evoked above: implementing the turbine without the mast, eliminating the cantilever effect on it and the requirement of guys. The turbine is tilted and an active control of the blades (or a lifter kite) can be needed to assure some lift along the (now tilted) axis used also as a tower as for @dougselsam SuperTurbine ™. If the turbine scales largely as the rpm becomes lower said active control becomes easier because it is less frequent. But it is another story.
Welcome Andreas. Really great commercial achievement . Video is really cool and powerful. Marketing a wind turbine is not an easy job ! Marketing an airborne one is insane…
The video inspired me for my next crowd campaign but not wind energy related. What is your plan about delivery time btw?
Glad if it could be used for inspiration! Delivery time will be December 2021
Marketing an airborne one is insane…
I’m actually curious to learn more about your experience taking an alternative turbine to market. Let’s setup call
Imo the best way to turn the concept into an true airborne system would be to convert the turbine to fly-gen and add active pitch control on the blade through actuated tails or a swatch plate like system.
I would like to experiment with the turbine in a fly-gen configuration, but we have decided not to do that yet due to the likely higher noise emissions.
That’s an order of magnitude more complex.
Tbere was a company, wich did basically this, originally for power generation and then pivoted to a system that could provide lift for antennas or cameras, while sometimes consuming power. Anyone know the name?
The lifter kite thing was just an idea to keep it simple. Take windmill, lift into air.
There is a bit more information about our power control strategy. Seems like we will go forward with a string/tether actuated pitch control system. The system also features a cyclic pitch components that help offset the adverse effect of wind-shear.
We have started to work on getting the edge case of the controller to work, which I hope is a good sign . Still there is work to be done testing the system robustness in adverse wind conditions: turbulent +10 m/s, high wind shear conditions.
We had good winds for the past two days in which we were able to test the high wind performance. We are currently quite happy abou the mechanical design.
If anything the main complain I/we have is that the rotor isn’t able to handle high torque at high pitch angles. Secondly the blades vibrate/flutter due the the geometry when the blades are pitch to ~90 degree in 10+ m/s gusts.
Nice video @aokholm Andreas
What was it that tripped the pitch to change at ~1min 10 sec?
It was certainly whipping around at quite a rate until that point.
Nothing too exciting. It was just us who decided that it was time end that part of the test.
In the general case the only condition we have atm in the automatic control is if the pitch set point goes above ~25 degree, then the turbine will automatically go to cutout mode.
It might be that we make the turbine rotate slower, by reducing the aerodynamic yaw stability by decreasing the cone angle. This does however decrease guy-wire clearance.
. Still there is work to be done testing the system robustness in adverse wind conditions: turbulent +10 m/s, high wind shear conditions.