19.2.1—The electric potential energy stored in a capacitor

Energy stored in a capacitor is electric potential energy associated with separated charge and the electric field between conductors.

Charging requires work against the growing potential difference; discharging transfers this energy to other stores or radiation.

A camera flash capacitor releases stored electric energy rapidly through a lamp circuit.

The dielectric does not create energy; it changes capacitance and the energy relation for a given Q or V.