I’m guessing you haven’t served. The front line military brings its own power, exactly portable gas/diesel generators, to run everything. If there is a usable power line with a transformer to a usable voltage and it hasn’t been yet damaged in the fighting, it’s amazing, but also fragile.

A non trivial chunk of signal corps training is learning the ins and outs of standard generators, conventions and apparatus for distributing power, equipment for converting between various voltages used by equipment 1 to 80 years old, etc.