JPH0586057B

PURPOSE:To eliminate the need for the installation of a superconductive energy storage device in a base rock, and to shorten the period of execution and reduce the cost of execution by disposing the superconductive energy storage device building in a superconducting coil and supporting expansion force acting on the superconducting coil by water pressure. CONSTITUTION:When currents are made to flow through superconducting coils 3, magnetic fields are generated around the superconducting coils 3, and stored as electromagnetic energy. Expanding electromagnetic force fe works on the superconducting coils 3 at that time. On the other hand, a water pressure corresponding to the depth of water acts toward the coil sides on the superconducting coils 3. Consequently, powerful electromagnetic force working on the side face 10a, etc., of a device is supported by water pressure when magnetic energy is stored. Accordingly, the device need not depend upon a base rock, thus reducing cost.