A method and apparatus for modifying standard AC plugs and receptacles to flexibly furnish AC or DC power is disclosed. This can be accomplished by adding a “selector” pin between the non-ground pins used in traditional AC plugs. Alternately, an interposer can be manually applied to the plug to effect selection. Plug electronics can select AC or DC based on respective availability. A flexible power receptacle can manage AC/DC selection, regulate the supplied DC voltage and enable reversion to the AC supply if the DC supply is inadequate. Electronics within a flexible power receptacle can convert DC to AC when advantageous and can regulate the supplied voltage. Additional electronics within a flexible power plug or receptacle can enable communication.