To summarize for anyone not reading the article:

German balcony solar panels are connected directly to their home power through a smart inverter that will kill power if the grid power goes down, so lines don't stay live when you'd think they are dead. Those devices are designed for the voltage and frequency of the German grid, and can't be used in America. Companies won't makes devices if they aren't legal to use, but one state has legalized it, so hopefully we get there soon.

The other issue is that a circuit breaker essentially monitors the amount of current going into your home's circuit from the grid as a way of preventing your wires from being overloaded. Since the micro inverter is on the other side of the circuit breaker, you could overload the circuit without tripping the breaker, and that is why they are limited to 800 W.