Flywheels store rotational kinetic energy in the form of a spinning cylinder or disc, then use this stored kinetic energy to regenerate electricity at a later time.
Flywheel energy storage system (FESS) is an electromechanical system that stores energy in the form of kinetic energy. A mass coupled with electric machine rotates on two magnetic bearings to decrease friction at high speed. The flywheel and electric machine are placed in a vacuum to reduce wind friction.
The operational mechanism of a flywheel has two states: energy storage and energy release. Energy is stored in a flywheel when torque is applied to it. The torque increases the rotational speed of the flywheel; as a result, energy is stored. Conversely, the energy is released in the form of torque to the connected mechanical device .
How efficient is a flywheel energy storage system?
Their efficiency is high during energy storage and energy transfer (>90 %). The performance of flywheel energy storage systems operating in magnetic bearing and vacuum is high. Flywheel energy storage systems have a long working life if periodically maintained (>25 years).
Can small applications be used instead of large flywheel energy storage systems?
Small applications connected in parallel can be used instead of large flywheel energy storage systems. There are losses due to air friction and bearing in flywheel energy storage systems. These cause energy losses with self-discharge in the flywheel energy storage system.
What are the disadvantages of Flywheel energy storage systems?
In addition, this storage technology is not affected by weather and climatic conditions . One of the most important issues of flywheel energy storage systems is safety. As a result of mechanical failure, the rotating object fails during high rotational speed poses a serious danger. One of the disadvantages of these storage systems is noise.
Where does a flywheel energy storage system come from?
Prof. Dr.-Ing. Günter Keller references including diagrams, figures and sketches. The input energy for a Flywheel energy storage system is usually drawn from an electrical source coming from the grid or any other source of electrical energy.