The quantum flywheel is an energy storage device. Stores vast amounts of energy in a rapidly rotating quantum field. Adding plasma "speeds up" the rate of spin. Slowing the rate of spin causes the flywheel to give off plasma.

Uses: Quantum flywheels can be used to "smooth out" the energy stream of power generation systems prone to fluctuating outputs. A small Quantum flywheel can be used as a "battery" for short-duration vessels, such as probes. A series of Quantum flywheels can be used to store excess output from a power source, then augment the power source during higher-than-normal power consumption, as in combat.