The generators work by burning fuel in exactly the same way as the engine of a car or truck does. The only difference is the diesel is as the name says it burns diesel fuel, not the standard highly combustible gasoline of a normal car engine or a normal generator. Diesel fuel so it burns hotter and more efficiently than normal fuel and, these days, can sometimes be even cheaper. The drawback is that it also sounds louder when operating, it is harder on the engine or generator (though diesel generators are, of course, to combat this difficulty), and if not treated properly, can produce more pollution. Because of the increased power diesel generators, often used for problems that require more power and more strength. Industrial generators usually are diesel generators, as only diesel generators can handle the type of energy needed to carry high levels of industrial applications.

Diesel generators are often seen in marine applications, from small boats up to full sized ships. In fact, are increasingly popular for use aboard large vessels simply because, unlike alternatives, diesel generators need not be placed near the propellers – this increased flexibility frees up valuable space for a vessel of load, and still generates strong and reliable power throughout the ship. Diesel generators are often also used for situations that require a lot of reliable power, as opposed to using normal gas generators for smaller jobs and sporadic. A gasoline generator, for example, could be used to keep the home computer network or the hot tub running in the event of a blackout. Large applications, on the other hand, need reliable power because it is absolutely fundamental – like a hospital – often require increased strength and reliability of diesel generators.