A power distribution system , comprising: a first power source having first power output characteristics; a second power source having second power output characteristics, wherein the second power output characteristics are different from the first power output characteristics; an alternating current (AC) power bus connectable with the first power source and the second power source ; an AC power source configured to supply controllable power output characteristics to the AC power bus , the AC power source comprising a plurality of power storage units configured to supply direct current (DC) power; a controller module configured to transfer supplying power from the first power source to the AC power bus to supplying power from the second power source to the AC power bus by connecting the AC power source to supply the controllable power output characteristics matching the first power output characteristics, disconnecting the first power source from the AC power bus , transitioning the controllable power output characteristics from matching the first power output characteristics to matching the second power output characteristics without ceasing the supplying of the controllable power output characteristics to the AC power bus including controlled or sequenced enabling and disabling of the plurality of power storage units , and connecting the second power source to the AC power bus ; wherein the transitioning the controllable power output characteristics from matching the first power output characteristics to matching the second power output characteristics comprises introducing a series of timing delays over a number of sequentially successive power or waveform cycles until a first AC waveform matches a second AC waveform , each of the timing delays being shorter than a reset power break period of time for a set of electrical loads connected with the AC power bus . a first power source having first power output characteristics; a second power source having second power output characteristics, wherein the second power output characteristics are different from the first power output characteristics; an alternating current (AC) power bus connectable with the first power source and the second power source ; an AC power source configured to supply controllable power output characteristics to the AC power bus , the AC power source comprising a plurality of power storage units configured to supply direct current (DC) power; a controller module configured to transfer supplying power from the first power source to the AC power bus to supplying power from the second power source to the AC power bus by connecting the AC power source to supply the controllable power output characteristics matching the first power output characteristics, disconnecting the first power source from the AC power bus , transitioning the controllable power output characteristics from matching the first power output characteristics to matching the second power output characteristics without ceasing the supplying of the controllable power output characteristics to the AC power bus including controlled or sequenced enabling and disabling of the plurality of power storage units , and connecting the second power source to the AC power bus ; wherein the transitioning the controllable power output characteristics from matching the first power output characteristics to matching the second power output characteristics comprises introducing a series of timing delays over a number of sequentially successive power or waveform cycles until a first AC waveform matches a second AC waveform , each of the timing delays being shorter than a reset power break period of time for a set of electrical loads connected with the AC power bus . <EOS>