Crosspost from https://beehaw.org/post/17685168
Maybe just look at how these inverters work before babbling about. These kits all come with standard off the shelf micro inverters, or rarely bigger string inverters, and will feed back up to 0,8wk into the grid if the energy is not used in the household. If the connection to the grid is lost they turn off within less than 50ms, making them completely safe for line technicians
and will feed back up to 0,8wk into the grid if the energy is not used in the household.
Even more precisely: If the energy isn’t used on the exact phase the inverter is connected to. You might be simultaneously backfeeding 800W on one phase and draw 3000W from the grid for your kettle on another, pretty much every single installation (at least in Germany) is three-phase at the main breaker panel, then distributing (and three-phase for the stove). Good ole Ferraris meters only record the total sum (the wheel would turn at the speed of 2200W) but you’re still using grid infrastructure which is one of the reasons why the installations have to be small: Because your utility can’t bill you for grid usage.