A 2012 New York Times article by James Glanz examined how data centers can be wasteful and consume a great deal of energy. In order to provide reliability, data centers need to store the same information on multiple machines to create redundancy. These machines need to be on and accessible all the time. On top of the need for constant power flowing to the servers, the data centers require cooling systems that pull more power.
According to Glanz's sources, data centers use around 30 gigawatts of electricity [Glanz]. He also states that data centers can waste most of that energy -- up to 90 percent of it. With that massive amount of power going to waste, is the Internet doing more harm than it's worth?
Not according to Raghavan and Ma. They point out in their report that the Internet's energy consumption is a fraction of that of the transportation industry, which accounts for 61 percent of all oil production [source: Raghavan and Ma]. The two researchers suggest that because the Internet uses less power and causes a smaller environmental impact than transportation, moving more tasks to the Internet makes sense. Using teleconferencing rather than travel for meetings could save quite a bit of energy.
The real picture that emerges when you look at how much energy the Internet uses is that it's a complex issue. Without the Internet, we would have to rely on other methods to communicate and access data. Those methods might in turn require more energy and cause more pollution than the Internet does. If that's the case, decreasing our reliance on these activities and focusing more on the Internet makes sense from an energy perspective.