A power supply device according to an embodiment comprises a plurality of power sources 10 each including an antenna and an AC/DC conversion unit, a plurality of consolidating units 13_1 to 13_i, and a power supply unit 15. The consolidating units 13_1 to 13_i respectively include consolidating circuits 14_1 to 14_i that selectively consolidate a plurality of DC signals 21_1 to 21_n supplied by the plurality of power sources 10. The power supply unit 15 includes a consolidating circuit 16 that selectively consolidates the DC signals 21_1 to 21_i output from the plurality of consolidating units 13_1 to 13_i, and a voltage conversion circuit 17 that converts a DC signal 23 resulting from consolidation in the consolidating circuit 16, to a predetermined voltage.