Internet uses 2% of global power
Two researchers, Justin Ma and Barath Raghavan, at the University of
California, Berkeley and the nearby International Computer Science Institute respectively, estimate that the internet consumes between 170GW and 307GW. Which raises the question: is that a big number, or a small one?
The researchers estimate that the planet is home to 750 million laptops, a billion smart-phones and 100 million servers. They also put figures on the energy that it costs to produce each of these devices (4.5GJ and 1 GJ for a laptop and smart-phone respectively) and the period for which each is used before being replaced (three years for a laptop, two for a smart-phone).
Estimates for the energy that cell towers and optical switches use when transmitting internet traffic, plus similar calculations for wi-fi transmitters and cloud storage devices, helped complete the picture.
Their final answer sounds big. A gigawatt is a billion watts, so running and maintaining the internet is like illuminating several billion 100W bulbs simultaneously. But it's a small number compared with global energy use across all sectors. That figure is 16 terawatts, so the internet is responsible for less than 2% of the energy used by humanity.
[Jim Giles, New Scientist]