Research engineers at NASA and US Flywheel Systems have developed a flywheel energy storage system that recently achieved full-speed operation at 60,000 revolutions per minute (rpm). The achievement represents the highest ever demonstrated for a flywheel levitated and spun on magnetic bearings and makes the wheel a possible candidate for replacing the chemical batteries on the International Space Station (ISS).
Team members developed or identified high-strength carbon fibre/epoxy composites for the rotor, low-loss magnets for the bearings, high-speed electric motor/generators for energy conversion, and computer algorithms for motion control.
The advantages of flywheels over chemical batteries are numerous. They can be designed to have a lifetime that matches that of the ISS; chemical batteries planned for ISS will only last about five years and must be replaced during the mission. Flywheels also operate effectively over a wide temperature range; chemical batteries operate well only within a narrow 0 to 10 degrees C range. They are more efficient, and return more of the energy put into them than chemical batteries.
On the ISS, electricity from solar arrays will run the motor that spins the wheel. Then, during the shade period of the orbit, the spinning wheels will turn the motor, now acting as generator, to make the electricity that powers science equipment and life support systems.Flywheel research at Glenn is part of its continuing effort to provide the power for the future exploration of space and other worlds.