Energy Storage Using Flywheels
How it Works:
Electrical energy or mechanical energy is used to spin the flywheel at great speeds and to store energy. The greater the rotational speed of the flywheel, the greater the amount of charge stored in it. Thus the energy is stored and it can be retrieved at a later point of time. The flywheel keeps spinning at a particular speed as long as energy is not retrieved from it. The speed at which the flywheel rotates is reduced when energy is retrieved from it. The flywheel stops spinning once all the energy is drained from the system.
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The parts of a Flywheel Energy Storage System:
1. Rotor - Initially it was made of a steel flywheel. Recent advancements has seen the use of carbon fiber composite rotors that are lighter and have higher tensile strength than their predecessors, the steel flywheels. The heavier and the greater the diameter of the rotor, the more the energy that can be stored in the rotor.
2. Bearings - The flywheel rotates on mechanical bearings. Lately magnetic bearings are used that are more efficient and further reduce energy lost due to friction. High temperature semi-conductors are used in the making of the magnetic bearings.
The rotor and bearings assembly is kept in a vacuumised environment to further reduce the friction.
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