Flywheel Energy Storage system works by stimulating a flywheel to an extremely high speed and managing the energy within the system as rotational energy. When energy is derived from the system, the rotational speed of the flywheel is decreased as a result of the law of conserving energy; the speed of the flywheel is increased if energy is added to the system. Most of the flywheel energy storage systems make the use of electricity in order to decelerate and accelerate the flywheel; however, devices using mechanical energy are being invented. Leading flywheel energy storage systems contain flywheels that are made of carbon-fiber composites that are high in strength, that spin at 20,000 to 50,000 rotations per minute. Such flywheels can catch up speed in just a few minutes and reach the capacity of their energy faster than other types of storage.
An ideal flywheel energy storage system contains a rotor stopped from activity inside the vacuum chamber in order to decrease friction, which is connected to a combination of electric generator and electric motor. Flywheel energy storage systems of first generation generally make use of a large flywheel of steel that rotates in mechanical manner. Advanced systems make the use of carbon-fiber composite flywheels possess a higher capacity to endure load known as tensile strength than steel and are comparatively lighter. In order to decrease the friction, magnetic bearings are used in place of mechanical bearings. To store energy, materials that are high in strength and that are in low in density are preferred. Hence, composite materials are used often in newer flywheels. The tensile strength that is used for the rotor is one of the major barriers in flywheel design. Basically, the more strength the disc has the faster it can be spun and the more energy will be stored.
Flywheel storage energy systems that make the use of mechanical bearings drop about 20% to 50% of energy in a period of two hours. Due to the earth’s rotation, the direction of the flywheel changes that results in the friction that causes loss of energy. The flywheels angular momentum applies gyroscopic forces that resist the change of direction and apply a force across the mechanical bearings. Friction is increased due to this force. This can be eliminated in the flywheels and the earth’s axis of rotation is parallel.
The flywheel energy storage system is useful in various applications such as pulse power, rail vehicles and electrification, amusement rides, motor sports, uninterruptible supplies of power, systems that are used for launching aircrafts, toys, wind turbines, tests and physics laboratories, toggle action presses and grid energy storage.