  We study the radiation emitted by inertial charge evolving on the expanding
de Sitter spacetime. Performing a perturbative calculation, within scalar
quantum electrodynamics (sQED), we obtain the transition amplitude for the
process and using this we define the energy radiated by the source. In the
non-relativistic limit we find that the leading term is compatible with the
classical result (Larmor formula). The first quantum correction is found to be
negative, a result which is in line with a number of similar quantum field
theory results. For the ultra-relativistic case we find a logarithmic
divergence of the emitted energy for large frequencies, which we link to the
nature of the spacetime. We compare our results with that of Nomura et al.
(2006), where the authors make a similar calculation for a general conformally
flat spacetime.
