Flywheel energy storage is a technology for storing energy in the form of a spinning flywheel. The energy is stored as kinetic energy in the flywheel, which can be used to generate electricity when needed. The flywheel is connected to an electric motor, which is used to spin the flywheel up to a high speed. When electricity is needed, the motor is used to slow the flywheel down, which generates electricity.
Some of the emerging trends in flywheel energy storage include the development of high-energy density flywheels, the use of flywheels for grid-scale energy storage, and the use of flywheels in hybrid electric vehicles.