The electromagnetic energy density and Poynting vector of a moving charge are computed by the Heaviside-Feynman formulas. The amplitude

(in meters) of the oscillator

in the

direction with the frequency

(measured in hertz) describes the moving charge in the

plane at

. The

component of the Poynting vector, the electric energy density, and the magnetic energy density of the oscillator are computed for an

region at arbitrary height

.The observation time point is when the charge is crossing the coordinate origin with negative velocity

. The speed of the charge varies from small values to the speed of light, and the Demonstration displays the resulting changes in the electromagnetic energy density and Poynting vector.