One big reason I didn’t go with Solar City is that they install DC systems, where all of the panels are wired in series DC down to a big monolithic inverter. Wi

One big reason I didn’t go with Solar City is that they install DC systems, where all of the panels are wired in series DC down to a big monolithic inverter. With such a system, shading is a problem, as you mention - one shaded panel will cut current for the whole string. You are also lucky that the plumber didn’t kill himself or burn down your house - DC systems often run hundreds of volts, and DC can sustain an arc with as little as 80V (http://www.acsolarwarehouse.com/news/solar-fires-dc-arc-faults-on-solar-systems/ http://www.acsolarwarehouse.com/news/solar-fires-dc-arc-faul...). AC systems have micro-inverters for each panel or panel cluster, so DC is never transmitted over large distances or at high voltage. Because each panel is independent, shading only affects the output of the shaded panel. You can also replace damaged panels or add to the system later without having to match the characteristics of the existing panels.