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Fri 17 Aug 2007 - 1:03 am UTC
What is the current total global energy consumption of the internet?
Included in this figure is the energy consumed by all the PCs in the world (when they are on!), as well as all the local hubs, regional data centers, company servers, the transmission lines run by telecoms and intermediate routers, etc. I'm not concerned with printers and other non-communicating devices. It should not include the energy needed to manufacture this infrastructure; but it should represent the energy required to run it and -- this is important -- the energy required to cool it. What is the utility bill for keeping the internet on? I would like this figure in the form of kilowatt hours, or ergs per time, rather than percent of total energy use, although that is nice too. And I need it for the planet.
Nearly a decade ago there was some attempt at this answer, but I am looking for current figures no more than a year or two old. For instance this article (Emerging Technology: Energy Consumption And The New Economy http://www.networkcomputing.com/showArticle.jhtml?articleId=8703032) which was issued in Jan 5, 2001, refers to an article written in 1999 which used equipment surveys from 1995 in its calculations. There was a second attempt to re-calculate this in Feb 1, 2001, in this article, Research Finds Computer-Related Electricity Use to be Overestimated http://www.lbl.gov/Science-Articles/Archive/net-energy-studies.html. This was for US use only. Of course the internet is more global now, and more ubiquitous, more 24/7, more vital, so I am looking for a more current appraisal. It may have to be cobbled together. There is a lot of controversy over any kind of large-scale measurement like this, so I'll take a range if there are more than one estimate. And show your work!
Sat 18 Aug 2007 - 12:17 am UTC
I've estimated the electricity consumption for the internet as follows:
US: 350 billion kWh per year
World: 868 billion kWh per year
These numbers represent 9.4% of total US electricity consumption, and 5.3% of global electricity consumption.
The breakout of the data is as follows:
Annual Electricity Use for the Internet--US and World
Category..........................US Consumption.......World Consumption
.....................................Billion kWh........Billion kWh
(1) Data Centers (includes cooling)......45.................112.5
(4) Phone network.......................0.4...................1.0
TOTAL ELECTRICITY DEMAND ~350 billion kWh ~868 billion
OF THE INTERNET ............................U.S.................World
The data were derived as follows:
(1) These data come directly from a recent report on data centers:
ESTIMATING TOTAL POWER CONSUMPTION BY SERVERS IN THE U.S. AND THE WORLD
Jonathan G. Koomey, Ph.D.
Staff Scientist, Lawrence Berkeley National Laboratory and
Consulting Professor, Stanford University
February 15, 2007
Note that the above report estimates global power consumption for servers as 2.5 times the US consumption...I used this scaling factor throughout my own estimates to "translate" data between US-scale and global-scale.
Also note that the report includes details on cooling and other data center needs, which are about 50% of total demand.
(2) Desktop computer power consumption was estimated as follows:
There are approximately a billion PCs in the world:
Worldwide PC Adoption Forecast, 2007 To 2015
June 11, 2007
...Forrester's 2007 worldwide PC adoption forecast shows that there will be more than a billion PCs in use by the end of 2008 and more than 2 billion by 2015 — a 12.3% compound annual growth rate (CAGR)
and the average PC and monitor uses about 588 kWh or electricity in a year:
How much energy do computers and their monitors use?
...The average PC/monitor combination consumes 588 kWh of electricity every year
Therefore, global electricity consumption for PCs is 588 billion kWh per year (dividing by the 2.5 scaling factor gives an estimate for the US).
(3) Networking equipment such as modems and routers also have a significant power draw. Data shows that networking components in an office setting account for about 1/4 the electricity demand of computers and monitors (that is, for every 100 kWh of demand from desktop PCs, another 25 kWh is needed for networking components):
PC Energy-Efficiency Trends and Technologies
[See piechart in Figure 1]
I assumed this ratio held across the board, so that the data in (3) are 25% of the values in (2)
(4) Most internet data is transmitted over telephone lines, and telephone system power draw is fairly small. This report:
Network Electricity Use Associated with Wireless Personal Digital Assistants
includes a table showing that total phone system use in the US is 3.8 TWh (3.8 billion kWh):
Table 1. Network and Phone System Direct Electricity Use
and another table detailing that internet use accounts for about 5% of overall phone traffic:
Table 2. U.S. Data and Telephone Traffic in 2000
Since VOIP technology has likely increased the proportion of internet-related phone traffic, I upped the percentage to 10% for my calculations. Still, the overall contribution is fairly small.
I did not see data on other transmission technologies, such as cable or satellite, though these are presumably small as well.
In addition to the above figures, I used electricity consumption data for the US and for the World from the following sources:
US Electricity - consumption: 3.717 trillion kWh
World Electricity - consumption: 16.33 trillion kWh
From the links you provided in your question, it seems clear that you're well aware of the controversies surrounding estimates of total elecricity demand of the internet. One of the real oddities of the controversies is the almost complete absence of any attempt to add up all major components of internet-related demand, as your question called for. There are many studies of individual components of the system (most of them quite dated), but no real attempt to get at the big picture.
The data I've presented here is no less subject to challenge than any of the other estimates out there. But it is a plausible attempt at just such a "big picture", using the most recent and well-regarded data I could find.
I hope this meets your needs. But if there's anything more I can do for you, just let me know by posting a Clarification request.
All the best,
Tue 21 Aug 2007 - 2:57 am UTC
Thanks so much. This was a very challenging and very interesting assignment. Let us know if there's anything more we can do for you on this.
Sun 7 Oct 2007 - 12:45 pm UTC
A bit of an update for anyone following this discussion.
The estimate presented here of the energy use of the internet has generated a bit of controversy. This isn't all that surprising since, as the question itself notes, "There is a lot of controversy over any kind of large-scale measurement like this..."
The weakest link in my analysis is most certainly the 588 kWh estimate for typical PC electricity consumption in the course of the year. As Dr. Koomey has noted, this is a dated estimate from a study by Verdiem, and does not likely reflect the current mix of computers in use.
Some factors, such as greater use of laptops, and a shift to LCD monitors, argues for lower overall energy demand. Other factors, such as higher processor speeds and greater graphics demands suggest increased power use.
I took another look for any more up-to-date figures on this, but, as Dr. Koomey noted, this figure does not appear to have been updated since the Verdiem estimate.
I also agree that it would be good for a new study to be funded that could provide a more comprehensive and more up-to-date overview of electricity use of the internet than was possible in the context of this particular Q&A.
I hope Dr. Koomey is successful in securing such funding, and my thanks to him, and to everyone else, who took the time to contribute to this very intriguing discussion.
Tue 13 May 2008 - 8:00 pm UTC
A bit of an addendum for anyone interested:
According to a presentation by the US Air Force:
Information and Communications Technology (ICT) Global CO2Emissions
information and communications technology (ICT) accounts for 2% of all greenhouse gas emissions worldwide (see the slide on page 33). Almost 2/3 of this amount is from PCs, monitors and servers.
Put another way, the power consumption of the computers and other equipment making up the internet account for more than 1% of global greenhouse gas emissions, at least according to this presentation.
Just something to chew on...
Mon 15 Jun 2009 - 5:16 pm UTC
Can't resist these little updates every now and then:
"...According to a report from an environmental consultancy...some 62 trillion unsolicited e-mails were sent in 2008, using 33 terawatt hours of electricity. That is equivalent to the energy consumed by 1.5m American homes or 3.1m cars over a year. If generated by coal-fired power stations it would release 17m tonnes of carbon dioxide, some 0.2% of global emissions of this greenhouse gas..."
Tue 12 Apr 2011 - 2:37 pm UTC
Every now and then, something comes along that I just feel I need to add to this question, such as a Microsoft study that cloud computing can reduce CO2 emissions 90% from small businesses, and from 30-60% in larger operations:
Cloud Computing and Sustainability
Other Microsoft environmental docs on cloud computing are here:
Wed 28 Dec 2011 - 6:59 pm UTC
k2k et al,
This is an interesting article:
Implications of Historical Trends in the Electrical Efficiency of Computing
The full article is subscription-only, but the abstract I linked to will give you the gist of it.
Sun 23 Sep 2012 - 6:48 pm UTC
Couldn't resist yet adding yet another updated piece of the puzzle:
Power, Pollution and the Internet
Thu 27 Jun 2013 - 2:46 pm UTC
Seems like once or twice a year, something new comes along to lend additional perspective. This latest report:
Power-Hungry Devices Use $70 Billion of Energy Annually
provides a lot of comparative detail on computers vs other devices in terms of overall energy use (apparently, ceiling fans are a surprisingly large energy hog).
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