Comparison of energy storage in flywheels and SMES

Generally valid expressions and scaling rules are derived, which relate the stored magnetic energy in a SMES and fly-wheel to the required minimum amo unt of superconducting, structural and stabilizing material. Results are wi dely independent of details like magnet type and dimensions, the only speci fic design variable is a magnetic coil length h. It is shown how the experi mentally observed design limit j(eff)(2)E(0) less than or equal to 2 x 10(2 3) J A(2)/m(4) follows from force arguments. (C) 2001 Elsevier Science B.V. All rights reserved.