superconducting magnetic energy storage (SMES)

Superconducting magnetic energy storage (SMES) technology uses the superconducting characteristics of low-temperature materials to produce intense magnetic fields to store energy. SMES has been proposed as a storage option to support large-scale use of photovoltaics and wind as a means to smooth out fluctuations in power generation. A major is to develop supercoducting storage systems that will work at higher temperatures.


An advantage of SMES is that power is available almost instantaneously, and very high power output is provided for a brief period of time. There is no loss of power, and there are no moving parts. A disadvantage is that the energy content of SMES systems is small and short-lived, and the cryogenics (cold temperature technology) can be a challenge.


Applications of SMES

Already dramatically used in such applications as high-speed, magnetic-levitated trains, superconductors are also being developed for use in microelectronics and communications.


SMES is also used in utility applications. Several 1-MW units are used for power quality control in installations around the world.


In northern Wisconsin, a string of distributed SMES units was deployed to enhance stability of a transmission loop. The transmission line is subject to large, sudden load changes due to the operation of a paper mill, with the potential for uncontrolled fluctuations and voltage collapse. Besides stabilizing the grid, the six SMES units also provide increased power quality to customers served by connected feeders.