A floating flywheel is an interesting idea, but the drag in the surrounding fluid: a) puts a limit the maximum speed and b) continually slows the flywheel down.

I propose using electrostatics to levitate a flywheel.

The flywheel is a toroidal shell made of a material of high tensile strength. The flywheel levitates in a slightly larger toroidal housing (e.g. a separation of 1cm), that has gas at a very low pressure (or a vacuum). The bottom half of the housing is electrostatically charged. The flywheel is given the same charge as the housing. A wire touches the flywheel to maintain its charge.

The speed of the flywheel is no longer limited by drag, and is instead limited by the tensile strength of the flywheel. Thus it would have a much higher energy density than the buoyant flywheel.
-- xaviergisz, Mar 03 2016

buoyant flywheel
[xaviergisz, Mar 03 2016]

Electric Forces between Charged Plates http://www-eng.lbl....electric_forces.pdf
[xaviergisz, Mar 03 2016]

The wire will slow the flywheel. I suggest using a stream of electrons or ions or something.

But I additionally suggest switching from electrostatic levitation (which requires quite high voltages, as you've seen) to magnetic levitation. Now, I don't mean electromagnets. I mean permanent magnets. This is already baked: Levitron.
-- notexactly, Mar 04 2016



random, halfbakery