Energy Requirements of the Internet
Barath Raghavan and Justin Ma from ICSI and UC Berkeley estimated how much energy the internet costs, not just in terms of kwh’s from the plug in the wall, but also the energy necessary to build all these devices that constitute the internet, clients like laptops, desktops, mobile devices as well as devices that provide the internet infrastructure like routers and servers. Here is a summary of the results:
Power consumption entire internet (incl. client devices) between 170 and 307 GW. That is between 1.1 and 1.9% of the total energy consumption of 16 TW. Devices: 750 million desktops, 750 million laptops, 1 billion smart phones, 100 million servers. Infrastructure: 1 million routers, 100 million LAN devices (cable modems to hubs and switches to WiFi access points), 5 million cell towers, 75,000 telecom switches, 1.5 billion km of fiber optic cabling and 3.5 billion km of copper cabling. Energy necessary to produce client devices: 7.5 GJ for a desktop (4 year lifespan), 4.5 GJ for a laptop (3 years) and 1 GJ for a smartphone (2 years). Substituting 25% of flights with video conferencing would save the amount of energy necessary to fuel the entire internet.
Note that there is considerable downward potential as consumers move en masse away from destops and laptops towards tablets (ipad consumes 2.5 Watt)