Difference between revisions of "Flywheel"

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(In space, should use a pair of flywheels in order to conserve angular momentum.)
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Flywheel batteries work by accelerating a rotor (flywheel) to a very high speed and maintaining the energy in the system as rotational energy. The energy is converted back by slowing down the flywheel.
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Flywheel batteries work by accelerating a pair of rotors (flywheels) to a very high speed and maintaining the energy in the system as rotational energy. The energy is converted back by slowing down the flywheels.
  
 
The space environment has a number of advantages for flywheel energy storage:
 
The space environment has a number of advantages for flywheel energy storage:

Revision as of 19:34, 3 March 2009

Flywheel batteries work by accelerating a pair of rotors (flywheels) to a very high speed and maintaining the energy in the system as rotational energy. The energy is converted back by slowing down the flywheels.

The space environment has a number of advantages for flywheel energy storage:

  • The natural vacuum eliminates energy losses due to atmospheric drag.
  • Cryogenic temperatures of space enable superconductor magnetic bearings that minimize friction in the system, without further refrigeration.
  • Energy losses due to friction, hysteresis etc. can be utilized to heat the spacecraft.
  • Due to the absence of living beings, minimal safety precautions, in case the spinning flywheel 'explodes', has to be made.
  • Because of their angular momentum, flywheels can act as reaction wheels for attitude control as well, even while storing energy.

Furthermore, in vehicles, such as a lunar rover, flywheels can stabilize motion due to the gyroscopic effect.

Current best theoretical energy densities of flywheel batteries are around 200 Wh/kg.