Dark energy waves absorb energy from photons in intergalactic space and the total energy of dark energy increases, increasing the acceleration of the universe. Because the dark energy is quantised when it absorbs energy from a photon it changes to a higher energy quantum state.If a cosmic microwave background photon has a wavelength of 10^ - 3 metres - an energy of 10^-23 J- then before it was redshifted it had an energy 1000 times greater-10^ -20 J.Over 10^26 metres - the current size of the universe - the photon loses 10^-20 - 10^-23 J = 10^-20 J. This is 10^-20/10^26 J/m i.e 10^ - 46 J /m. If an absorption of photon energy by dark energy takes place every 10^ -14 seconds - the photon will travel 10^-6 metre before emitting 10^-46 x 10^-6 = 10^-52 J to dark energy waves. Using h = E x t we find that 10^ - 52 x t = 10^ - 34 t = 10^18 seconds. This means that dark energy will emit the energy it has picked up from photons 10^18 seconds after having done so -the current age of the universe. When it does emit the photon energy the universe will deccelerate as the amount of dark energy decreases and gravity dominates.