In combination with established standards for electrical safety, FESS can be safely installed and operated (as are other storage systems) while providing the additional environmental benefits of non-chemical, non-toxic, fully recyclable materials with scrap values rather than scrap costs.
Flywheel Energy Storage Systems (FESS) play an important role in the energy storage business. Its ability to cycle and deliver high power, as well as, high power gradients makes them superior for storage applications such as frequency regulation, voltage support and power firming.
How much energy can a flywheel store?
The small energy storage composite flywheel of American company Powerthu can operate at 53000 rpm and store 0.53 kWh of energy . The superconducting flywheel energy storage system developed by the Japan Railway Technology Research Institute has a rotational speed of 6000 rpm and a single unit energy storage capacity of 100 kW·h.
The use of new materials and compact designs will increase the specific energy and energy density to make flywheels more competitive to batteries. Other opportunities are new applications in energy harvest, hybrid energy systems, and flywheel's secondary functionality apart from energy storage.
Therefore, the selection of appropriate rotor materials and the design of rotor structure are the key to reducing the cost of flywheel energy storage, which is crucial for the promotion of flywheel energy storage. Several review papers address different aspects of FESS research.
The flywheel energy storage system mainly stores energy through the inertia of the high-speed rotation of the rotor. In order to fully utilize material strength to achieve higher energy storage density, rotors are increasingly operating at extremely high flange speeds.
Dai Xingjian et al. designed a variable cross-section alloy steel energy storage flywheel with rated speed of 2700 r/min and energy storage of 60 MJ to meet the technical requirements for energy and power of the energy storage unit in the hybrid power system of oil rig, and proposed a new scheme of keyless connection with the motor spindle.