The article proposes a model of energy-cost distribution, which relate electricity flows in all sections of the electric grid with the cost of generation, transmission and sale of electricity. The model allows to distribute the full cost of electricity supply between the nodes of the supply of electric energy, taking into account the power losses and the degree of use of all elements of the network, thereby determining the node prices (tariffs), which give estimates of the unit cost for generation, transmission and sell of electricity.