The problem of energy concentration in combustion waves is considered. On the example of natural flames with an energy excess it is shown these flames can exist in various systems and different combustion regimes. The existence of some flames such as cellular and spin itself is due to an excess energy. The mechanisms of energy concentration are also varied. Besides the heat exchange processes such as conduction, convection, radiation the mass exchange processes, filtration, phase transformations and compressibility of gas may participate in the energy concentration. Although the phenomenon itself is known for a long time but its properties, characteristics and peculiarities are insufficiently studied. On the other hand, the given examples of flames with artificially created conditions for energy concentration demonstrate the wide applicability of this phenomenon.