A project team from Graz University of Technology (TU Graz) recently developed a prototype flywheel storage system that can store electrical energy and provide fast charging capabilities. Flywheels are considered one of the world’s oldest forms of energy storage, yet they are still relevant today.
First-generation flywheel energy-storage systems use a large steel flywheel rotating on mechanical bearings. Newer systems use carbon-fiber composite rotors that have a higher tensile strength than steel and can store much more energy for the same mass. To reduce friction, magnetic bearings are sometimes used instead of mechanical bearings.
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.
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.
When charging, electrical energy from the grid or a power source is used to accelerate the flywheel to very high speeds. This is done by the motor/generator acting as a motor, converting electrical energy into kinetic energy and storing it in the spinning flywheel.
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.