These noisemakers are handy to have when the power goes out. The most common use is for the water pump, but you can also keep a filled pressure tank in your water system for emergencies. Another good reason for backup power is for electric fans in the summer here in FL.
Generators require fuel, and this explosive mix needs to be stored away from the barn. Many outdoor generators outside the barn have the fuel tank buried. A competent electrician should install generators because you do not want that generator feeding power lines outside the house and electrocuting a repairman working on the troubled line.
Here are some examples of generators I have seen on farms.
Side note – Solar panels with or without a battery storage system will also do the trick without the noise or volatile fuel.