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The Technology Transfer and Partnerships Office
Flywheel Electromechanical Batteries

Storing energy using flywheel technology for spacecraft applications

Flywheel energy systems are simple in concept. An electric motor is used to spin up a wheel or rotor to store energy, and energy is discharged by an electric generator, thus spinning down the flywheel. While the electromagnetic battery concept is decades old, recent advances in high-strength lightweight composite materials, magnetic bearings, and power electronics technology have brought renewed interest in flywheel energy storage technologies. Advances make possible flywheel speeds that can equal or exceed the energy storage capability of traditional chemical batteries. NASA’s Glenn Research Center invites companies to license this flywheel technology, which has implications not only for spacecraft applications but also for the transportation, utility, and manufacturing industries.

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  • Lightweight: Increases applicability and reduces floor loading through lower weight per unit energy storage
  • Reliable: Provides life expectancy that is 5-10 times greater than chemical batteries and reduces by up to a factor of 25 the mean time between failures
  • Safe: Uses no hazardous chemicals
  • Flexible: Adapts to different sized systems
  • Widely applicable: Extends uses to attitude control and vibrational damping, in addition to energy storage

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    • Electric or hybrid vehicles
    • Pulsed power devices
    • Uninterruptable power supplies
    • Load-leveling applications
    • Peak power applications
    • Long life-cycle applications
    • Satellite attitude control

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       Technology Details 
      How it Works

      Flywheels store kinetic energy, as opposed to chemical energy. As energy is generated, the flywheel increases in speed by spinning up through the motor. When energy is required, the flywheel inertia is converted to electrical energy in the motor generator. Flywheel components include magnetic bearings to levitate the rotor, a motor generator for increasing the speed of the rotor and for converting rotational energy into electrical energy, a flywheel hub and composite rim that stores the energy, touchdown bearings for backup during magnetic bearing failure, and power electronics for power conversion and control. Internal converters supply power to the magnetic bearing actuators to levitate the rotor. Flywheels can be considered for use in applications that demand many charge/discharge cycles, high efficiency repeated deep discharge capability, high specific energy and power characteristics, and rapid charging or discharging capabilities.

      Why it is Better

      Glenn's flywheel energy system technology has the capability to provide lower weight, 5-10 times longer battery life, and 10-20 percent higher efficiencies than traditional batteries. Additionally, users can expect more reliability and greater operational flexibility.

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      For inquiries about this technology, please reference LEW-17262-1.

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       Licensing and Partnering Information 

      For information and forms related to the technology licensing and partnering process, please visit the Working with GRC section of our Web site.

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      If you would like more information about this technology, please contact:

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      • Page Last Updated:
        October 14, 2014
      • Page Editor:
      • NASA Official: