How much power does the flywheel store

Do flywheels store more energy?

The laws of physics (explained briefly in the box below—but you can skip them if you're not interested or you know about them already) tell us that large diameter and heavy wheels store more energy than smaller and lighter wheels, while flywheels that spin faster store much more energy than ones that spin slower.

How does a flywheel energy storage system work?

Flywheel Energy Storage Systems (FESS) rely on a mechanical working principle: An electric motor is used to spin a rotor of high inertia up to 20,000-50,000 rpm. Electrical energy is thus converted to kinetic energy for storage. For discharging, the motor acts as a generator, braking the rotor to produce electricity.

What percentage of energy is stored in a flywheel?

A 1977 US Department of Energy pamphlet titled Flywheels: Storing Energy as Motion stated a goal of achieving 70 percent efficiency by 1980. By 2010, the Department of the Navy: Energy Fact Book (p.489) was quoting 80–90 percent as a typical figure.

Are flywheel energy storages commercially available?

Flywheel energy storages are commercially available (TRL 9) but have not yet experienced large-scale commercialisation due to their cost disadvantages in comparison with battery storages (higher investment, lower energy density). Another challenge is the comparably high standby loss in FESS caused by the magnetic drag of the motor-generator.