You ignore the initial outlay to buy the solar system in the first place. Like I said. Nothing in life is free.Others do ... depends on your climate ... solar is a tough sell here in the rain forests westside ... because our hydro is cheapest-in-the-nation ...
But if the estimates in your hands don't add up ... then I'd pass if I were you ... plants shade trees and ditch your air conditioner ...
If you live in San Diego, where the electricity prices are high, and your solar generation is awesome, then your break even point is measured in as few as 5 years, depending on your energy usage.
Up here where I live, a standard solar system doesn't reach break even point for over 16 years. Plus we have additional maintenance costs that san diegans don't have thanks to our wildlife (bears having fun with hardware) and weather.
I have a very good solar system, with 65k ah battery backup because our grid fails not infrequently with our snow storms, I am actually amazed we haven't had an outage with this last storm, but I don't like not having power, so I built a system much larger than I need, just to ensure I have what I want.