Expressions are given for the interference energy flux (IEF) of the active and reactive components of co- and counterpropagating waves with an arbitrary structure of their electromagnetic field. The formation conditions of the IEF and its role in energy transfer processes are analyzed in the examples of homogeneous plane waves in an absorbing medium, directed planar-waveguide modes, and a system of radiating dipoles. The possibility of using the IEF for controlling the radiation, transfer, and dissipation of electromagnetic energy is discussed. The IEF of the waves of two coherent sources is shown to contain two interrelated components, which control different energy processes.