I installed a 10KW P.V system 10 years ago. The company installed a pile of systems, then went disappeared to avoid warranty work. The payback was about 6 years, so that was the only saving grace. If your in a climate that gets snow, then be prepared to clean the snow off. You can leave the snow on, but your generation will take a hit. My system has micro-inverters that convert the dc of each panel to AC. I have had to replace 5 of them in 10 years (of 45 inverters). The inverters have a 15 warranty (Enphase) so they were covered. I change them myself, so avoid paying someone else. If you have a shingled roof make sure you reroof before installing your panels. The panels will last at least 25 years, so don't get caught with the roof needing re shingling before that. Overall, I wouldn't do it again.