To calculate how much energy is lost along the path from generator to consumer, you must know what share of entire consumer’s load (reciprocal current) is covered by said generator. Proposed method is based on fundamental laws of electrical engineering. By given set of generator currents, the consumer loads can be considered linear. This renders possibility to determine reciprocal current consecutively connecting each generator to the grid other generators being disconnected. In simulation procedure, the generators are presented by their generated current and loads – by their impedances. The simulation is made resorting to node voltages method.