@kjj -

It's probable the extra energy comes from Zero Point Energy.
Energy in space was battering the atoms and effecting (the electrons orbital shifts) their movements
According to Robert S. Mulliken in noting anomolies in the Red Shift
Max Plank, Albert Einstein, Otto Stern, Walther Nernst recognized that this pervasive (Zero Point) energy was a universal phenomena and intrinsic to space.
Werner Heisenberg understood that Planck's Constant was actually the measurement of the uncertainty in position of subatomic particles. By 1962, it was realized that this uncertainty of position was caused by the battering from "the Zero Point Energy".
In 1987, Hal Puthoff showed that electrons stayed in their orbits and did not go either spinning out or spinning in due to expended energy precisely because of the energy they received from the Zero Point Energy.
Zero Point Energy is 10^95 ergs/cm^3
It has Permattivity, Evo (Absolute dielectric constant); Permiability, Uva (absolute magnetic constant); Intrinsic impedance, Z = {Evo/Uva}^1/3