Solar kytoons

This potential design comes from the double observation of the difficulty of implementing AWES not including an aerostat, and the disadvantages of gases lighter than air, and in addition the practical limits of the Magnus effect.

Different combinations including a blimp are in the forum, such like Magnus effect + solar, Is an electrically heated balloon lift support for AWES possible?, Info on hydrogen and (tethered) hydrogen aerostats, AWES using LTA with PV for hydrogen production on board.

Some observations: the power consumption of a Magnus-based effect balloon is significant and likely prevents a useful use when the linear peripheral speed of rotation exceeds wind speed, so when the coefficient of lift becomes interesting. And the configuration to spin the balloon is not easy as it scales, even with external belt. Otherwise hydrogen is dangerous for a long term use. Helium is expensive.

So the purpose is avoiding the drawbacks above while including a (solar) aerostat. It should be large enough, having a double envelope in order to keep some heat, even by night or without sun during several hours or days, in order to keep the airborne system aloft all the time. Both (crosswind or not) yo-yo and (stationary) turbines aloft uses can be studied.

Designs such like LTA windpower or TARS could be transposed into solar versions. In my opinion other designs including larger wings could be studied. ETFE foil could be an appropriate choice for the external envelope, and perhaps Tensairity ™ for the whole.

As balloons and blimps are the greatest existent aeronefs (all the things flying) kytoons could allow scaling more, in addition to their cumulative aerostatic and dynamic lift.

After some recent researches it turns out that the aerostatic lift would be too low and the losses too great at night to keep the balloon constantly in flight, unless perhaps its dimensions were really gigantic. MIR (a solar balloon in free flight, not a tethered balloon) is described on:

Another link on the original French website:
https://cnes.fr/fr/web/CNES-fr/9194-aerostats-montgolfieres-infrarouges-mir-page-1.php

That said the solar aerostatic lift would decrease take-off and landing operations. And above all the inflatable structure is a proven mean to scale.

1 Like