This happend a couple years ago in Germany. The actual challenge for the local utility company (one of the biggest 4) was not to compensate the missing energy o

This happend a couple years ago in Germany. The actual challenge for the local utility company (one of the biggest 4) was not to compensate the missing energy output from solar, but in calculating the optimal backup energy plan to buy on the future/spot market. If you buy too much or not enough upfront, it just gets expensive. But the whole problem is keeping the cost low. Not a black out. Friend of mine was in the dev-team for the spot trading software. (Sorry for my english)