At their behest, the consulting firm McKinsey & Company analyzed energy use by data centers and found that, on average they were using only 6 percent to 12 percent of the electricity powering their servers to perform computations. The rest was essentially used to keep servers idling and ready in case of a surge in activity that could slow or crash their operations. "Worldwide, the digital warehouses use about 30 billion watts of electricity, roughly equivalent to the output of 30 nuclear power plants." In other words, “A single data center can take more power than a medium-size town.” This is the price being paid to ensure everyone has instant access to every email they've ever received, or for their instant Facebook status update. Data Center providers are finding that they can't rack servers fast enough to provide for users' needs: “It is absolutely a race between our ability to create data and our ability to store and manage data,” Mr. Burton said.
A few companies say they are using extensively re-engineered software and cooling systems to decrease wasted power. Among them are Facebook and Google, which also have redesigned their hardware. Still, according to recent disclosures, Google’s data centers consume nearly 300 million watts and Facebook’s about 60 million watts.
Many of these solutions are readily available, but in a risk-averse industry, most companies have been reluctant to make wholesale change, according to industry experts."