Internet Energy Consumption
E-commerce is made possible by an always on communications infrastructure, the Internet. Communication over the Internet often traverses not only network cables but also several computers, routers, switches, hubs and other equipment and significant energy.

In fact, the current fuel-economy rating estimates that about 1 pound of coal is needed to create, store a send 2 megabytes of data. (Dig more coal -- the PCs are coming, Peter W. Huber, Forbes Magazine, 05.31.99). The average Internet home user is on-line 12 hours per week (Forbes/IntelliQuest Study). Estimates indicate that each PC connected to the Internet requires around two to three other pieces of network equipment. Each one of these network components requires a significant amount of power. For example, Cisco's 7500 series router, can transfer over 400 million bits per second but uses 1.5 kilowatts of power.
Figure: Computer Messages flow across a number of routers and
networks to reach their ultimate decision. Each piece requires energy.

Example: MIT to Amazon.com

The experiment below conducted at 4:05 EST on Monday, December 10th shows the path of a packet traveling from MIT (Cambridge,MA) to Amazon.com (Seattle, WA). The single packet traverses at least 15 routers and many more network links, gateways, and other network devices. Dowloading a web page often involves a number of packets being sent back and forth between the requester and the requestee.

traceroute to amazon.com (207.171.183.16), 30 hops max, 40 byte packets
1 W92-RTR-1-W92SRV16.MIT.EDU (18.7.16.1) 0.707 ms 0.584 ms 0.525 ms
2 EXTERNAL-RTR-BACKBONE.MIT.EDU (18.168.0.18) 205.618 ms 17.144 ms 533.195 ms
3 p3-0.cambridge1-cr1.bbnplanet.net (4.1.80.9) 4.011 ms 4.014 ms 2.818 ms
4 p4-2.cambridge1-nbr1.bbnplanet.net (4.1.80.6) 4.922 ms 4.817 ms 4.698 ms
5 p3-0.cambridge1-nbr2.bbnplanet.net (4.0.5.18) 3.006 ms 4.432 ms 3.043 ms
6 so-4-1-1.bstnma1-nbr2.bbnplanet.net (4.24.5.33) 3.377 ms 3.755 ms 4.544 ms
7 p2-0.bstnma1-cr8.bbnplanet.net (4.24.5.126) 4.274 ms 4.051 ms 4.253 ms
8 p1-1.xbstnma8-verio.bbnplanet.net (4.24.94.22) 4.067 ms 4.118 ms 4.612 ms
9 p4-1-0.r01.bstnma01.us.bb.verio.net (129.250.3.150) 3.885 ms 4.058 ms 4.005 ms
10 p1-0-2.r00.clevoh01.us.bb.verio.net (129.250.3.226) 24.960 ms 25.267 ms 24.653 ms
11 p4-6-1-0.r02.chcgil01.us.bb.verio.net (129.250.2.29) 25.282 ms 24.281 ms 23.898 ms
12 p16-3-0-0.r00.chcgil06.us.bb.verio.net (129.250.5.114) 25.042 ms 25.509 ms 25.619 ms
13 p16-2-0-0.r04.sttlwa01.us.bb.verio.net (129.250.2.6) 96.118 ms 94.881 ms 97.099 ms
14 ge-0.amazon.sttlwa01.us.bb.verio.net (129.250.10.10) 96.825 ms 96.441 ms 96.967 ms
15 191-15.amazon.com (207.171.191.15) 93.919 ms 93.966 ms 94.126 ms

Other Studies

Numerous large scale studies have been conducted on the energy use of the Internet. Some studies estimate that the Internet consumes 7% of the United States power while new others estimate it consumes around 2-3%. One report on Internet energy use may be found here.

Next Section: Pervasive Computing

Source of both Figures: Cisco Systems, Inc.