Tokyo Electricity announced that they'll do planned blackouts because we don't have enough electricity.
The nuclear power plant in Fukushima broke(it's actually more serious than that, see here) and we don't have enough energy. So we're saving it by, well, the usual turn-off-the-lights activity, like this.
But that wasn't enough, so we're having blackouts that are already planned ahead.
So, getting ready for it.