Google’s data center electricity use is about 0.01% of total worldwide electricity use and less than 1 percent of global data center electricity use in 2010,” Koomey writes, while cautioning that his numbers represent educated guesses extrapolated from the company’s information. “This result is in part a function of the higher infrastructure efficiency of Google’s facilities compared to in-house data centers, which is consistent with efficiencies of other cloud computing installations, but it also reflects lower electricity use per server for Google’s highly optimized servers.”