Energy Efficiency Improvement of Renewable-Rich DC Microgrids by SMES Cables

This article reports on the compensation of output power fluctuation of renewable energy and the improvement of energy use efficiency of renewable energy by superconducting cable with energy storage function (SMES cable). This improvement in energy use efficiency is based on the ability to maximize the use of electrical energy from renewable energy sources as it is in real time, no matter how severe the output power fluctuation occurs. After reviewing the advantages of SMES cables, examples of their use in 10-MW-class microgrids are discussed. The results show that the use of SMES cables can improve energy use efficiency by more than 40% compared to the use of no SMES cables. In addition, the corresponding reduction in energy costs is also estimated.