Stored energy is known as Potential Energy.

Glycogen is the stored reserve of sugar in the body. It is converted into glucose if our muscles need to respire.

I don't believe there is a special word for stored energy, I would just call it that, "stored energy".

Energy of position is called potential energy. For example, if you lift a weight against the force of gravitation, the energy you transfer to the object is stored as gravitational potential energy. At a higher position, it has more of this energy than when it is at a low position.

The stored food in an egg consists mostly of protein. This is used for energy as the fetal animal grows inside the egg.

potential energy.