Flywheel energy storage (FES) works by spinning a rotor (flywheel) and maintaining the energy in the system as rotational energy. When energy is extracted from the system, the flywheel's rotational speed is reduced as a consequence of the principle of conservation of energy; adding energy to the. . As a result, when it's spinning at high speed, it tends to want to keep on spinning (we say it has a lot of angular momentum), which means it can store a great deal of kinetic energy. This innovative technology offers high efficiency and substantial environmental benefits. When excess electricity is available, it is used to accelerate a flywheel to a very high speed.
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