One thing to consider. Yes, I jokingly have been saying this, but, as it turned out, it ended up kind of being true.
I've wondered since seeing my first solar panel on a rook how they eventually replace shingles. My joking way of saying it was that years later the people involved in both industries (roofers and solar panel companies) will suddenly realize, "oops, one BIG thing we all kind of overlooked: how do you replace shingles?!"
I never could find out online, but, as I suspected, I spoke to a guy who installs solar panels and his quick and easy answer for me was, "you can't replace them, once the panels are in." Apparently, that's why most who install them have a metal roof installed then install the panels.
HOWEVER, another problem that I always brought up with those, to which no one disagrees: metal fades, so those metal rooks, many years down the road, are going to look ugly, like old steel and aluminum siding eventually does.