This is a simple project of 3600rpm rotovertor motor spinning a large red-painted fywheel made of drywall discs sandwiched between two wood discs.
The rotovertor motor actually got down to little less thant .3 amps input at 120VAC input after some tuning to it.
The motor can run at its high rpm rated speed since the flywheel is spun by a small rubber wheel on shaft of motor and this keeps the  draw of the motor down to low amps since  the motor  is not forced to "lug itself" in order  to spin the flywheel,:


The idea of this project is for a large Muller-type of plate-altenator mounted on the flywheel shaft as shown in photos below:
This plate-alternator can be pulse-charging large bank of batteries to supply an off-grid home or business with electricity on only 36 wtts continuous power feed to the rotovertor motor.
Also the rotorvertor motor itself can charge additional batteries using a battery-charging circuit from it (see "rotovertro-battery charging circuits" link in sidebar)