How does panel shut-off work for emergency responders? Where I live, a solar energy system is required to have a shut off switch. For example, my system has a big red handle mounted on the side of the house. This is important not just for first responders like firefighters but also for linemen repairing downed lines, which are pretty common where I live (a mountainous rural area).
Given that these store-bought panels are being plugged into house AC, it follows that they have built-in inverters. Many grid-tied inverters are “grid follow”, meaning that they adjust themselves to grid frequency/phase. So, just speculating here… maybe the inverter senses when the mains go down and turns itself off? I would love to know from an EE what is actually happening wrt safety.