We say that there is energy associated with electric and magnetic fields. For example, in the case of an inductor, we give a vague answer saying that an energy of 12LI2 1 2 L I 2 is stored in the magnetic field around the inductor. For a capacitor, we say that energy is stored in the field.
The energy stored in the magnetic field of an inductor can do work (deliver power). The energy stored in the magnetic field of the inductor is essentially kinetic energy (the energy stored in the electric field of a capacitor is potential energy). See the circuit diagram below. In the diagrams the voltage source is a battery.
Applications of Magnetic Energy: Stored magnetic energy has practical uses in mechanical systems and electronic applications, demonstrating the versatility of magnetic fields in technology. Magnetic field can be of permanent magnet or electro-magnet. Both magnetic fields store some energy.
Every magnetic field contains some form of energy, which we generally refer to as Magnetic Energy, W m. With the energy stored in a magnetic field being one of the fundamental principles of physics, finding applications in various branches of science and technology, including electromagnetism and electronics.
Superconducting magnetic energy storage (SMES) systems store energy in the magnetic field created by the flow of direct current in a superconducting coil that has been cryogenically cooled to a temperature below its superconducting critical temperature. This use of superconducting coils to store magnetic energy was invented by M. Ferrier in 1970.
Since the magnetic energy stored in a field is best described by its energy density, the energy per unit volume, it is stored in the space around the coil (primarily inside the coil for a solenoid). Inside the solenoid, the magnetic field lines run parallel to the axis of the coil, and the energy is stored in the space where these lines exist.