On loss of power these inverters cut off within 20 ms or so. These are grid-tied, not insular (though with hacked firmware some of the models can be madeninsular-capable).

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