Wow, that's seriously impressive. We hooked up some panels to our site trailer last year and cut our generator use by a third. The fuel savings alone paid for the setup in like six months. It's one of those things that seems too good to be true until you see the bills drop. Really glad it's working out for you too.
Yeah that payback time makes sense if you factor in generator upkeep too. @rileyd43 probably didn't think about oil changes and filter costs piling up on top of the fuel. I mean, once those panels are up you're pretty much just cleaning them sometimes, idk it just seems way less hassle long term.