Can Energy Be Contained?

Question

Self explanitory.

Answer 1

Potential energy: yes. Examples are chemical potential energy as in a battery, or mechanical potential energy as in a compressed spring.
Kinetic energy: also yes, but only in a closed loop. An object in straight-line motion couldn't be held in a container of defined size, but rotary motion such as a mass running around a track or a spinning flywheel could.
There is an interesting duality in the storage of electromagnetic energy in a superconducting electromagnet (which is also containable). Electric energy is input to build up the electromagnet's circulating current against the back EMF of the inductance. The stored energy can be considered either kinetic (in the form of the current circulating in the closed loop) or potential (in the form of the resulting static magnetic field). Whichever form you consider it to be in, it is rapidly dissipated as an electric discharge when the current loop is opened and the magnetic field collapses.

Answer 2

The most common containment we have for energy in common use is chemical containment.
Energy can be used to bond different chemicals together, which "holds" the energy for it to be released once the bond is broken.
Our own bodies do this all the time... this is how we get energy to use throughout the day from food. See also: battery.

So yes, of course we can contain energy. Or else all energy would dissipate instantly and we'd die a horrible Heat Death.