By some estimates, Google has the equivalent of 25000 racks of hardware, maybe at most a quarter of them hosted in the shared facilities where they turn the lig

By some estimates, Google has the equivalent of 25000 racks of hardware, maybe at most a quarter of them hosted in the shared facilities where they turn the lights off, say 6000 racks of hardware. Continuing my calculation, that would be 3000 ~20W fluorescent light strips. If running 24/7, they would consume 530 MWh/year. This is only $53k/year at the average utility rate of $.10/kWh. If you continue to argue that Google, a company making $30B+ of revenue/year, turned off the lights to save a meager $53k/year, you are making a fool of yourself. They would save more by merely firing this secretary who smokes cigarettes in the bathroom during lunch breaks. Google is all about efficiency, down to giving technicians scooters to quickly move through large data centers, and choosing the optimal placement of velcros strapping hard disks to the chassis for ease of service. I bet they would rather leave the lights on rather than fumble with headlamps or flashlights... Clearly the article is right, Google did it for privacy reasons.