In every roof mount installation, one endeavor is always the same: the panels are on top of the house, and the electrical service equipment is in the basement. NEC 690 states that you need to be inside of EMT conduit if you are running DC above 60v indoors. It's not really possible to snake conduit through walls without completely dismantling the sheetrock to fasten the conduit properly. Some newer houses are pre-equipped with chaseways, which are often in PVC. Some inspectors have allowed PV installers to run either EMT or flexible metal conduit down large PVC chaseways, often at the request of homeowners who don't want external PV runs on their house. I can't blame em.
This is a good example of the ideal situation, regarding the entry to the house of the DC wires from the array, and the run from the combiner box to the exterior wall.
