My system automatically disconnects, to prevent injury to linemen. But there are several big honkin disconnects on the system, which even if I flipped, the system supposedly does not supply any energy to the house if the utility is offline. They call this Islanding.

That being said, why couldn't a couple of big contactors that would flip and prevent energy to being sent back to the utility be able to be installed and prevent that. Really not a big deal, but supposedly illegal here. Yet if you have backup battery system, it can operate with no utility power. Not sure how they do that.