"At peak consumption, usually from May to mid-December, CERN uses about 200 megawatts of power, which is about a third of the amount of energy used to feed the nearby city of Geneva in Switzerland."
Well, not quite. They don't shutdown in the first place because of the power usage, but they choose the timing for the shutdown when it is most economical. Regular maintenance is unavoidable.
(not joking)
http://home.cern/about/engineering/powering-cern
"At peak consumption, usually from May to mid-December, CERN uses about 200 megawatts of power, which is about a third of the amount of energy used to feed the nearby city of Geneva in Switzerland."