Flywheel energy storage (FES) works by accelerating a rotor (flywheel) to a very high speed and maintaining the energy in the system as rotational energy.
Flywheels, one of the earliest forms of energy storage, could play a significant role in the transformation of the electrical power system into one that is fully sustainable yet low cost.
Thanks to the unique advantages such as long life cycles, high power density, minimal environmental impact, and high power quality such as fast response and voltage stability, the flywheel/kinetic energy storage system (FESS) is gaining attention recently.
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.
Other opportunities are new applications in energy harvest, hybrid energy systems, and flywheel’s secondary functionality apart from energy storage. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Indeed, the development of high strength, low-density carbon fiber composites (CFCs) in the 1970s generated renewed interest in flywheel energy storage. Based on design strengths typically used in commercial flywheels, σ max /ρ is around 600 kNm/kg for CFC, whereas for wrought flywheel steels, it is around 75 kNm/kg.