Kyushu Electric released details of its plans for rolling blackouts this summer in the event of a power shortage. If the utility anticipates their surplus supply capacity will disappear, they will give two hours advance notice for a rolling blackout. They have divided the region into 60 groups, and will cut off electricity to a maximum of 10 groups for two hours each in sequence. There would be only one blackout in each group per day.
Here are some useful links:
Kyushu Electric Power Co., Inc. – English Website:
Overview of planned outages