During energy storage, electrical energy is transformed by the power converter to drive the motor, which in turn drives the flywheel to accelerate and store energy in the form of kinetic energy in the high-speed rotating flywheel . The motor then maintains a constant speed.
Electric energy input accelerates the mass to speed via an integrated motor-generator. The energy is discharged by drawing down the kinetic energy using the same motor-generator. The amount of energy that can be stored is proportional to the object’s moment of inertia times the square of its angular velocity.
Mechanical energy storage systems take advantage of kinetic or gravitational forces to store inputted energy. While the physics of mechanical systems are often quite simple (e.g. spin a flywheel or lift weights up a hill), the technologies that enable the efficient and effective use of these forces are particularly advanced.
The operation of the inertial storage system is based on the conversion of energy into a kinetic form, which is then converted to electrical energy when necessary. A flywheel is driven by a reversible electric machine that initially operates as a motor to supply energy to the inertial mass.
The motor then maintains a constant speed. During energy discharge, the high-speed rotating flywheel drives the generator to generate electricity, which is then output to loads in the form of current and voltage through the power converter, completing the process of releasing energy from mechanical energy to electrical energy.
Mechanical energy storage can be added to many types of systems that use heat, water or air with compressors, turbines, and other machinery, providing an alternative to battery storage, and enabling clean power to be stored for days. Explore energy storage resources Simple physics meets advanced technology.