From start to finish Polaron was very professional. I have a 1997 kit home with no attic(cathedral ceilings through out), therefore the engineers could not see the supports for the roof. They were prepared to walk away rather than say "It will probably be OK." Not until I found a way (through a closet) to confirm that my roof could actually support the weight that would be on it, would they proceed. Just got my first power bill, last year for the same period was 323.77, this year was 25.77. I have a app on my phone that enables me to see exactly what each of the panels is doing at any time during the day.