Energy Density #8211; The energy stored in a capacitor is not localised on the charges on the plates but is distributed in the field. In case of a parallel plate capacitor, electric field is only between the plates in a volume (A times; d), which is so called energy density. i.e. 1/2ε<sub>0</sub>E<sub>2</sub> Unit of energy density is J/m<sup>3</sup>