"I'm responsible for the design and construction and these things," says Urs Hölzle, Google's Senior Vice President of Operations. "Also, when Google.com goes down -- that would be my problem."
Not only is Hölzle charged with keeping the data centers humming, he also has to make that process as efficient as possible. "One of the key reasons for doing that is because it actually saves money," Hölzle says. "This isn't an expense that we do to look good, although obviously it does make it look good and we're happy and proud about that."
There are a couple of easy ways to cut energy costs, he says. One is to make sure that each server in the data center has its own battery instead of channeling the power for the servers through a giant room full of batteries first.
Another is to use modern machines that don't need to be cooled the way older ones did. These efforts have paid off, Hölzle says. Most data centers have 100% overhead, he says, meaning that every watt of power that the servers use requires another watt of power for cooling, fans and pumps. But Google's centers have only 16% to 17% overhead. In the future, the company wants to take that number down to zero.