# Flywheel and energy storage

chandran
What is energy?How a flywheel stores energy? What is the physics behind that?

Inertia. A flywheel is meant to have a mass that is, compared to the system it is in, rather large. Once the flywheel is brought up to operating speed, it's inertia helps to eliminate or reduce speed fluctuations in the system.

Homework Helper
Gold Member
The energy in a flywheel is E=(1/2)Iw^2.
By making the wheel rotate, this energy can be stored.
The energy can later be used by connecting to the rotating wheel.

Antiphon
Energy is the ability to do work.

pocoman
No, I think the abillity to do work is potential energy. Energy is the sum of kinetic energy and potential energy.

Gza
pocoman said:
No, I think the abillity to do work is potential energy. Energy is the sum of kinetic energy and potential energy.

So you are implying that only potential energy can do work? How would you explain a collision situation when an object (such as a billiard) collides with another billiard to change the kinetic energy of the collided billiard(changing it's velocity to a nonzero value, thereby giving it a kinetic energy)? (any change in energy is caused by work being done, therefore the colliding billiard did work on the collided billiard.)