A movable electrical generation system includes a generator operable to produce a supply of electrical energy, a prime mover operable to drive the generator, and a first fuel supply selectively deliverable to the movable electrical generation system in a first pressure range. A second fuel, different from the first fuel is selectively deliverable to the prime mover in a second pressure range. A controller is operable to automatically deliver the second fuel to the prime mover in response to the first fuel having a pressure outside of the first pressure range.