The structure of electromagnetic energy flows in continuous media

A formulation of electromagnetism in continuous media is proposed that relies on the identification of the different existing electromagnetic energy reservoirs and of the flows between them. A structure is so revealed, which constitutes a natural framework to establish the partial differential equations ruling electromagnetic systems. This energy-based formulation, which unlike Maxwell´s equations also integrates the material aspects, clarifies several issues related to dissipative and coupled phenomena in magnetic materials, dielectrics and conductors