A key question is: What does it do to the life of your roof covering and any warranty you have on same? About 5 years ago I spent a bit over $US20k on a new asphalt shingle roof with a 50 year warranty on materials and 20 year warranty on labor. Does the solar company guarantee that the roof warranty isn't compromised? Also what does the roof installation company say about installing solar with respect to leaks, shingle damage, etc? I live in Northern California where we have enough sun days to make energy harvesting pay, but I have been concerned about the consequences for roof life and integrity.