Longman Dictionary of Contemporary English
power failure
noun
EXAMPLES FROM CORPUS
▪ Finally, an emergency lighting kit should always be ready in an accessible place, in case of a sudden power failure.
▪ Half way between Victoria and Gatwick there was a power failure, the lights went out and the train ground to a halt.
▪ It's only a power failure.
▪ The average freezer will keep food frozen for two days in the time of a blackout or a power failure.
▪ The last locally-caused power failure of greater magnitude was the Loma Prieta earthquake in October, 1989.
▪ This will prevent the loss of much of your work in the event of a power failure or other mishap.
WordNet
power failure
n. equipment failure resulting when the supply of power fails; "the ice storm caused a power outage" [syn: power outage]