One or more embodiments of a system for operating a vessel is provided herein. An illustrative system can include a plurality of power sources for operating the vessel. The power sources can include a battery bank and an AC power source. The system can also include an auxiliary device disposed on the vessel, wherein the auxiliary device comprises an electrical rotating source. Energy can be harvested from the electrical rotating source and transferred to the DC power source, a load of the vessel, or both. The illustrative system can also include a power management system that can include a processor; a data storage in communication with the processor; and a plurality of computer instructions stored on the data storage.