If you stay in China for a limited time you probably won’t notice it. In all the hostels they have these big emergency lighting boxes everywhere, and I just couldn’t understand why they would bother since rules in China are very slack.
I realised why when I was walking down the corridor at night and suddenly all the lights went off and these big emergency flood lights sprung into action. I spoke to one of the hostel staff about this. It seems to be a common problem in China, there is just not enough power. He went on to say that it would happen around 3 times a month.