New roof solar system (many questions)

[TLS Guy]

So, back on track, the First guy's quote was about $42k, including a new roof. Seemed a bit expensive at the time, but many benefits would quickly make it very worthwhile. That is for 23 panels sized at 10kW production.

I got quotes from the second round, this time separate numbers for the new roof (with a few small additions) and solar. The numbers are quite shocking. The roof alone is over 20k, and the solar system
It is nearly 52k for an 11.7kW system. So the total project cost with the second option is over $72k before benefits. For now, I am still trying to wrap my head around such big numbers, and getting more clarity from both vendors to understand why so such a difference.

What is the rating of your electrical service at the panel? You can only produce 20% above the rating of your panel. If you exceed that it will not pass inspection by Federal law. That is NEC 24. I have a 200 amp service so, the most panels I can have is 20 which is 7.6 KW. That gets by as peak power never quite gets to spec. although mine will produce 7.5 KW in a bright noon day sun.