power 7 [noncount] a : energy that can be collected and used to operate machines
The car's engine yields more power while using less fuel.
— see also horsepower, manpower
b : the electricity that people use
We lost power during the storm.
Do you know how many watts of power your refrigerator uses per day?
Whenever a learner like me looks up a new word in a dictionary, he or she expects to see some very common examples that most people use.
For example, when I looked for the word "power", the first thing that came in my mind was "how to express that we have or don't have power to run a machine"
But some dictionaries don't have this kind of common examples.
So, let's say "you took your laptop / radio to a library & you plugged its cable into a socket & there was no power, what you you say in this situation"