Is energy always conserved?

one could also question that just as a compressed spring the space of the universe is being PUSHED to expand. there are quantum fluctuations that are ripples ins space and that contains energy as a spring. now in order to relax the universe "spring" the universal fluctuation need to expand. so energy still may be conserved but in the total of the energy in the universe and light waves just contribute to the expansion  and the lights energy is simply used to expand the universe so light energy is converted to mechanical energy in the space expansion.