  Starting from the energy-momentum of matter and gravitational field in the
framework of General Relativity and Teleparallel Gravity, we obtain the
energy-momentum complex in flat FRW spacetime. We show that the complex
vanishes at background level considering the various prescriptions, that is the
Einstein, M{\o}ller, Landau-Lifshitz and Bergmann ones. On the other hand, at
level of linear cosmological perturbations, the energy-momentum complex is
different from zero and coincides in the various prescriptions. Finally, we
evaluate the gravitational energy for different cosmological epochs governed by
non-relativistic matter, radiation, inflationary scalar fields and cosmological
constant.
