A comparison of the conductor requirements for energy storage devices made with ideal coil geometries

Superconducting magnetic energy storage (SMES) plants have previously been proposed in both solenoidal and toroidal geometries. The former is efficient in terms of the quantity of superconductor required per unit of stored energy. For applications where a fringe field could be a problem, the toroidal geometry, which requires at least a factor of two more material, has been proposed. In addition to the solenoid and toroid, other geometries are possible, such as linear multipoles and spherical coils. These geometries have been considered for use in applications other than energy storage. Here the effectiveness (quantity of superconductor/stored energy) is calculated for various coil geometries