Did I say "run out" of electricity?
When you live in a high-rise in Beijing, paying your electric bill is nothing like you might expect. Writing a check to Pepco or PSE&G and mailing it out or taking care of it online is for most people unheard of in China. Instead, you need to buy your electricity as you need it.
In order to purchase electricity in Beijing, you must obtain a card, much like a top-up card for cell phones on a pay-as-you-go plan. Then you can go to almost any bank and add money (and therefore units of electricity) to your card. Once you have figured out this process (just one of those baby steps that foreigners need to learn by doing!), you take your card back to your apartment building and insert it into a slot in a box that has a digital meter on it. Once you insert it, the units are added and you are all set.
Just don't forget to check the box from time to time to see how many units you have left...or you may find yourself in the dark...without air conditioning...taking an icy cold shower.
Been there, done that.
PS: If you are still humming that song, I am deeply sorry.