The New York Times has posted a lengthy piece on data centers - the buildings that power web services, store our data, and more. They interviewed Michael Manos, a former Microsoft employee:
At Tukwila — as at any big data center — the computing machinery is supported by what Manos calls the “back-of-the-house stuff”: the chiller towers, the miles of battery springs, the intricate networks of piping. There’s also what Manos calls “the big iron,” the 2.5-megawatt, diesel-powered Caterpillar generators clustered at one end of a cavernous space known as the wind tunnel, through which air rushes to cool the generators. “In reality, the cloud is giant buildings full of computers and diesel generators,” Manos says. “There’s not really anything white or fluffy about it.”
It is a long - but fascinating - read about what makes the Internet tick.