An energy supply system for electrical actuator of a motor vehicle having a engine and battery includes a generator adapted to be driven by the vehicle engine to provide electrical energy to the electric actuator and vehicle battery. A control unit sets an input power provided to the generator by the vehicle engine and is configured to set the output voltage of the generator based on a power request associated with the electric actuator. A method for supplying electrical energy to a vehicle subsystem may be performed using an energy supply system as disclosed.