Abstract: The development of flywheel energy storage(FES) technology in the past fifty years was reviewed. The characters, key technology and application of FES were summarized. FES have many merits such as high power density, long cycling using life, fast response, observable energy stored and environmental friendly performance. A single flywheel stored energy of 0.5~130 kW·h in charging or discharging with power of 0.3~3000 kW. The frontier technologies include new materials of flywheel rotor, super-conducting magnetic bearing and high speed motor for FES. The commercial using of FES in power quality and uninterrupted power supply has a niche market share. The fuel saving in 20%~30% was realized in the hybrid power system using FES in vehicles. The FES technology is in a crisis of vehicles industrial application under the pressure from energy-saving and emission-reduction. For the grid application of renewable energy, the single FES stored energy of dozens of kWh should be increased to hundreds of kW·h. The power of FES array should be 10~100 MW and release power long as one hour.

Key words: flywheel energy storage, wind power, electrical vehicle, power quality, frequency regulation