I recommend an inverter type generator, often called a low speed generator, where the AC output frequency is created and has nothing to do with the speed of the motor. They save on fuel as the generator can slow right down and save fuel under low and no load situations.
How does that work?
Through most of an electricians training, we are taught that the output frequency of an alternator is based upon it's rotational speed, could be 50Hz, could be 60Hz, but the prime mover still has to be moving at a constant speed to achieve that frequency, all the time, not speeding up and slowing down.
