Abstract: According to one embodiment, each of the nodes incorporated in the respective electrical apparatuses that constitute a local power system establishes a communication path connected to any adjacent node, transmits and receive average supply-and-demand state data to and from the adjacent node through the communication path. Each node adjusts (increases or decreases) the power to generate or consume in it, on the basis of the average supply-and-demand state data. Each node performs a supply-and-demand control of distributed and coordinated type, in which the average supply-and-demand state value is corrected based on the value by which the power has been adjusted (increased or decreased) and the average supply-and-demand state value thus corrected is supplied to the adjacent node through the connection path.