Check out this video describing flywheel energy storage technology created by NASA.
The applicable standard from the NGSS is:
HS-ETS1-3 (high school). Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics, as well as possible social, cultural, and environmental impacts.
Discuss flywheel energy storage with respect to the standard.
From watching the video, what are the two ways in which energy loss due to friction is eliminated in flywheel energy storage?
The two ways are:
1) Using magnetic levitation to “float” the flywheel as it spins, rather than using bearings as support, which – although they are made to have as little friction as possible – still have a bit of friction and are still a source of energy loss as a result.
2) Spinning the flywheel in a vacuum in order to eliminate air friction which slows the flywheel down and is a source of energy loss.
Why is the flywheel shown in the video shaped like a ring?
Because for an object of a given mass, the highest rotational inertia is achieved when it is shaped like a ring. The basic physics here is that an object has more rotational inertia the farther its mass is located from the center of rotation. And the higher the rotational inertia an object has, the more kinetic energy it can store for a given rotation speed. This is desireable when designing flywheel energy storage systems for maximum efficiency, since you want maximum energy storage capacity for a given mass of flywheel. To learn more about flywheel physics click here.