The solar inverter is the box that converts direct current (DC) electricity into alternating current (AC) electricity. Put simply, it's the part of your rooftop solar system that makes the electricity from your solar panels useable. Unlike solar panels, which are mounted on the roof, the solar inverter is placed on the wall outside your home or inside in somewhere like your garage or laundry. It is installed undercover and ideally in the shade. There are three main types of solar inverters; stand alone inverters, grid-tied inverters and battery back up inverters. And there are lots of brands of inverters.