Design aspects of mid-size SMES using high temperature superconductors

Conceptual designs of modular, cold-supported superconducting magnetic energy storage (SMES) units using high-temperature superconductors (HTSs) were investigated over the mid-size energy range of 2 to 200 MWh. This size range covers many utility, industrial, and military applications. Both toroidal and solenoidal configurations were analyzed to determine physical dimensions, heat loads, and cost of major components. Among the effects considered were the impact of critical current density on feasible configurations, mass of conductor, and cost: the effects of magnetic field and strain limits on physical parameters and structural mass; and the savings in refrigeration from operating at a higher temperature. The design of the HTS conductor, stability criteria, and coolant selection are also discussed.>