Thursday, September 12, 2013

Keep calm: Your iPhone does not use more energy than your refrigerator

With all the talk about the new iPhones, here’s a mythbuster!


The internet was buzzing last week with the release of a report that made some pretty big claims, including the startling statement that an iPhone uses more energy each year than a refrigerator.

But a closer look at the data behind the report reveals that not only are there too many variables in smartphone data use to accurately make a blanket statement like that, but that the figures used in the calculations may be dubious as well.

When the headlines of articles about the report, "The Cloud Begins With Coal," began flying around the web, the claim that the ubiquitous smartphone and the infrastructure behind them were responsible for large amounts of electrical consumption seemed just far-out enough to be true, and a number of news sites just ran with it and shared it with their readers, without fact-checking it or questioning the claims, especially this one:
“Reduced to personal terms, although charging up a single tablet or smart phone requires a negligible amount of electricity, using either to watch an hour of video weekly consumes annually more electricity in the remote networks than two new refrigerators use in a year." (emphasis added)
But the story caught the eye of Jonathan Koomey, Ph.D., a Research Fellow at the Steyer-Taylor Center for Energy Policy and Finance at Stanford University, who found it to be riddled with errors and false assumptions and rebutted the conclusions from the paper in a piece at Think Progress.

"Mark Mills created headlines in the past week by claiming that all the power needed to bring data to the iPhone, plus all the related energy to manufacture it and the related network equipment, makes it responsible for as much electricity as two refrigerators. A more careful analysis confirms that Mr. Mills has overestimated the electricity associated with an iPhone by at least a factor of 18." – Koomey

Koomey goes into quite a bit of detail on the background of the issue, from the complexity in determining the energy demand of smartphones and their effect on cell or data networks, to the errors he's found in Mill's previous claims of high energy consumption for handheld devices.
[Neither Mills nor Koomey include figures for the direct electrical demand for powering smartphones, or the electrical use for the data centers or networks, as they are considered to be relatively small when compared to the other factors.]

In his piece, Koomey dissects the claims made by Mills, adding a fair amount of necessary background on the issue of calculating the energy use attributed to a smartphone and the demand it puts on the networks they connect to. He then goes on with his own detailed analysis of the issue, following a parallel path to Mills, but with a different conclusion, one which calls into question the media's ability to report sensibly on technical issues.

"The big story here is why the media is paying any attention to this report at all. Mr. Mills proved more than a decade ago that he is not a reliable source on the issue of electricity used by information technology, and his recent work simply confirms this. Unfortunately, it also confirms what seems to be an inability of most media outlets to report sensibly about technical topics, in part because of the pressure to generate attention-getting headlines, regardless of their veracity." – Koomey