A system for providing back-up AC electrical power to a first load device adapted to be powered by a utility-provided AC power source, the system including: an AC generator, including a generator output; a first switch, coupled between the utility-provided AC power source and the first load device, the first switch including a first switch-control input node; a fault detector including an input coupled to the utility-provided AC power source to detect a fault condition at the utility-provided AC power source, and including an output coupled to a timer, an inverter circuit, and to the first switch-control input node to operate the first switch to isolate the first load device (102, 400A) from the utility-provided AC power source when the fault condition is detected; the timer being coupled between the AC generator and the fault detector, the timer and being operable to start the AC generator after the fault condition is present for a predetermined period of time; the inverter circuit, including an inverter input coupled to a rectifier, and an inverter output coupled to the first load device to supply AC power to the first load device when the fault condition is detected; the rectifier, coupled between the AC generator and the inverter, converting the generator output to a DC output signal provided to the inverter input; an energy storage device is providing power to the inverter when the fault condition is detected and during a delay period before the AC generator starts; a first DC-to-DC converter, including a first converter input and a first converter output, the first converter input coupled to the energy storage device, and the first converter output coupled to the inverter input; and an energy supply circuit, including an energy supply circuit output coupled to the energy storage device, and an energy supply circuit input adapted to be coupled to the utility-provided AC power source outside of the system and to the AC generator output. an AC generator, including a generator output; a first switch, coupled between the utility-provided AC power source and the first load device, the first switch including a first switch-control input node; a fault detector including an input coupled to the utility-provided AC power source to detect a fault condition at the utility-provided AC power source, and including an output coupled to a timer, an inverter circuit, and to the first switch-control input node to operate the first switch to isolate the first load device (102, 400A) from the utility-provided AC power source when the fault condition is detected; the timer being coupled between the AC generator and the fault detector, the timer and being operable to start the AC generator after the fault condition is present for a predetermined period of time; the inverter circuit, including an inverter input coupled to a rectifier, and an inverter output coupled to the first load device to supply AC power to the first load device when the fault condition is detected; the rectifier, coupled between the AC generator and the inverter, converting the generator output to a DC output signal provided to the inverter input; an energy storage device is providing power to the inverter when the fault condition is detected and during a delay period before the AC generator starts; a first DC-to-DC converter, including a first converter input and a first converter output, the first converter input coupled to the energy storage device, and the first converter output coupled to the inverter input; and an energy supply circuit, including an energy supply circuit output coupled to the energy storage device, and an energy supply circuit input adapted to be coupled to the utility-provided AC power source outside of the system and to the AC generator output.