Editing Energy storage (section)

==== Superconducting magnetics ====
{{Main|Superconducting magnetic energy storage}}

Superconducting magnetic energy storage (SMES) systems store energy in a [[magnetic field]] created by the flow of [[direct current]] in a [[Superconductivity|superconducting]] coil that has been cooled to a temperature below its [[Superconductivity#Superconducting phase transition|superconducting critical temperature]]. A typical SMES system includes a superconducting [[inductor|coil]], power conditioning system and refrigerator. Once the superconducting coil is charged, the current does not decay and the magnetic energy can be stored indefinitely.<ref name="Hassenzahl" />

The stored energy can be released to the network by discharging the coil. The associated inverter/rectifier accounts for about 2–3% energy loss in each direction. SMES loses the least amount of [[electricity]] in the energy storage process compared to other methods of storing energy. SMES systems offer round-trip efficiency greater than 95%.<ref name="Cheung-Cheung-De Silvia-Juvonen-Singh-Woo" />

Due to the energy requirements of refrigeration and the cost of [[superconducting wire]], SMES is used for short duration storage such as improving [[power quality]]. It also has applications in grid balancing.<ref name="Hassenzahl" />