11.8 million -- The number of computer servers in the USA in 2007, up from 2.6 million in 1997 (source: IDC).
30.3 million -- Total number of computer servers worldwide. Also growing fast.
1/2 -- Half of the energy consumed by a typical data center (the place where the servers are housed) is used to remove the heat they generate: air-conditioners, fans, etc.
15% -- Most computers in the average data centers run at 15% capacity or less, idling the rest of the time but still consuming electricity. Thankfully, the trend is going in the right direction and the whole industry is looking for ways to reduce energy usage data centers.
25 -- By 2011, data center energy use could almost double and require the equivalent of 25 power plants. In the US, they are already (since 2006) using more energy than color televisions. "According to recent study from McKinsey & Company, could well surpass the airline industry as a greenhouse gas polluter by 2020." Source: New York Times