Flywheel energy storage devices could be looked at as a radical application of very traditional technology. They work by maintaining rotational energy by moving a flywheel. This same idea is used to keep a mechanical watch ticking.
A majority of modern FES devices use electricity to put the flywheel in motion, but some researchers are interested in the idea of using mechanical energy to start and stop the wheel. Modern devices stored in vacuum enclosures can spin at speeds exceeding 50,000 RPM. By using high strength carbon filaments that are suspended by magnetic bearings, FES installations can transfer energy in ways that conventional methods can’t.
Storing energy has always been a problem. Underground hydroelectric plants are sometimes used to store potential energy and flood the power grid with it during peak usage times. Chemical batteries are the storage solution that most people are familiar with. These are used in everything from automotive applications to TV remotes. However, neither of these options is ideal.
When people criticize solar and wind energy, they usually bring up the fact that neither technology works when weather conditions aren’t right. It’s hard to store solar or wind energy for use later. Flywheel energy storage systems would be perfect for these applications.
Some very ingenious people have brought this idea into the transportation industry. Using futuristic railroad vehicles, flywheel proponents have been able to build vehicles that can move up to fifty people 15 miles on one gallon of fuel. Self-propelled train cars can charge up their flywheels from an electrical supply provided at each station stop. The charging process would only take 30 seconds.
There are actually several niche industries where flywheels are already making a pretty big impact. Testing circuit breakers might sound like boring work, but its completely necessary in a society so reliant on electricity to stay connected. The amount of energy needed to fully trip a circuit breaker is immense, so it wouldn’t be possible to do this kind of job off grid power. Flywheels provide a ready source of stored power that doesn’t cause brownouts.
Amusement rides suffer from the same problem. Flywheels are starting to revolutionize the way that amusement parks store energy for things like roller coaster lifts. Even though this doesn’t sound like the most important field of research, it’s helping to cut down on how much energy these machines draw from the grid.
NASA has even gotten a good bit of publicity as a result of their G2 flywheel installation. They would certainly make good storage systems for orbital platforms. Future space colonies could use them to store power for peak usage times. That would allow people to continue to use appliances in space the same way they use them on terra firma.
Zhang, C., & Tseng, K. (2007). A Novel Flywheel Energy Storage System With Partially-Self-Bearing Flywheel-Rotor IEEE Transactions on Energy Conversion, 22 (2), 477-487 DOI: 10.1109/TEC.2005.858088
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