As others have said, its the surroundings, usually the air around the items. I would like to add that this energy is only wasted if you are in a hot climate with windows/doors open or air conditioners on to cool the property. If you are in a cold climate with doors and windows shut and heating on then the energy given off as heat is not wasted but contributes to the heating of the property. This would show up as a reduction in the energy used for heating directly. The push by governments for low energy lighting is, as a result, erroneous in the claims for the amount of energy that will be saved if all lighting was switched to high efficiency types in cold climates. This is also true for the claims about the amount of energy wasted by equipment left on standby.