Power estimation device, power estimation program, and power estimation method

A power estimation device comprises: an extraction unit for, from a plurality of intervals obtained by dividing power information at intervals of a constant period, extracting an interval analogous to the last power information, said power information being the information in which values relating to input/output power that is input to or output from a node (16) by one or a plurality of power devices (21-25) including a natural energy power generation device are described in time series; and an estimation unit for, based on the power information after the time corresponding to current time in the analogous interval, estimating the input/output power after the current time.