Every PV system that generates AC power contains at least one inverter, which converts DC power to AC before it can be used or fed back into the power grid.

Inverters store direct current inside capacitors. The capacitors discharge the stored electricity when inverters are de-energized, but until this process is complete, they can still deliver an electrical shock. Always treat inverters as if they contain dangerous voltage.

Industry standards require inverters to shut off within a fraction of a second if power is lost or goes out of a certain range. In this situation, the inverter will only turn back on after power has been restored for 5 continuous minutes. Be aware that home-built systems may not include this safety feature.

• Some PV systems, known as series grids, have all panels connected to a single inverter; if one panel in a series grid fails, it can disable the whole system.
• Other systems contain multiple microinverters, one at each panel. They are typically mounted on the back of the panels, so you may not notice them at first glance. If the system contains microinverters, use caution: even when one panel is disabled, others may still be energized.