2017 年 58 巻 4 号 p. 303-310
Flywheel energy storage systems (FESS) can moderate fluctuations in output from renewable energy such as solar photovoltaic power or wind power generation systems. A FESS was developed as a joint project involving five enterprises with financial support from the New Energy and Industrial Technology Development Organization (NEDO). The key technology used in FESS is the high temperature superconducting magnetic bearing (SMB). It consists of high temperature superconducting coils used for its stator and high temperature superconducting bulks used for its rotor. A FESS prototype was installed in the power plant, and its charge/discharge of solar photovoltaic power was monitored. Results from tests using a SMB subjected to a levitation time of 3,000 hours, 120 current value increase and decrease cycles and 24 heat cycles verified the reliability of the SMB.