I rolled my new roof into the "solar project", meaning I got the 30% tax credit on the new roof as well. You need to talk to a solar company. Perhaps start with Costco Sunrun.I can completely agree with you there on mortgages from the heart, even though my head says to borrow and invest.
I've also been considering roof mounted solar. The only things keeping me from it is the uncertainty of a 22 year old tile roof, and the possibility I may move before it's amortized.
You need to look at all the numbers to see if it makes sense for you. It made sense for me; I love my solar panels!