| I'm intrigued by Dr. Post's statement regarding electrostatic rather than electromagnetic force. When I think of the "motor-generator" component of a flywheel-based energy storage device, coils and magnetic poles and all that electromagnetic to/from mechanical energy conversion stuff comes to my mind. Electrostatic to/from mechanical energy conversion is known [1] [2], but not to my knowledge known for sustained high power and energy density appropriate for practical flywheel-based energy storage. Intriguing to consider that Dr. Post's research might be going in such a non-traditional direction as electrostatic motor-generators. Perhaps there are some incremental efficiency gains or design simplifications to be had in using the flat plates, good insulation and high voltages characteristic of electrostatics instead of the big coils, cores and high currents of electromagnetics. That said, there's no free lunch: No matter which electrical-to-mechanical-to-electrical energy conversion mode used may be, the energy stored remains rotational kinetic energy, thus limited by the same critical physical limitations (failure modes, maximal energy density, maximal power density) of traditional (electromagnetic, to date) flywheels. -------- [1] https://en.wikipedia.org/wiki/Electrostatic_motor [2] https://en.wikipedia.org/wiki/Electrostatic_generator |