The electricity used by iPhones and refrigerators, take two
Joe Romm at Climate Progress was good enough to post my analysis of the recent claim that your iPhone uses as much electricity as two refrigerators. This issue was highlighted in Friday’s edition of NPR’s Marketplace program, which thankfully didn’t fall into the false balance trap that many journalists find irresistible. Here’s the short summary and introduction, which will give you the overall picture:
Short summary
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. Unfortunately, some parts of the media seem unable to ignore this verifiably false but otherwise quite memorable headline.
Introduction
Last week several of my friends alerted me to a claim that the iPhone uses as much electricity as two refrigerators when you count the energy needed to make it, run it and power the “behind-the-wall” equipment to deliver data to the device. Discussion of the original report (“The Cloud Begins with Coal”, hereafter CBC) showed up on the Breakthrough Institute site, Time Magazine Online, MSN News, the Huffington Post, MarketWatch, and Grist, among others (with most focusing on the comparison between a smart phone and one refrigerator.
When I heard this claim, it took me back to the year 2000, when Mark P. Mills and Peter Huber first made the claim that the networking electricity for a wireless Palm VII exceeded the electricity for running a refrigerator (1000 to 2000 kWh, they claimed, the lower bound of which was a bit higher than the average installed base for US fridges at that time). It didn’t sound plausible, and so I and some colleagues investigated, finding that Mr. Mills and Mr. Huber had overestimated the electricity needed to feed data to a wireless Palm VII by a factor of 2000 (Koomey et al. 2004).
Just as happened last time, Mr. Mills, in the CBC report, has made attention-getting claims that don’t stand up to scrutiny (Kawamoto et al. 2002, Koomey 2000, Koomey 2003, Koomey 2008, Koomey et al. 1999, Koomey et al. 2002, Koomey et al. 2004, Romm et al. 1999, Roth et al. 2002). He cherry picks numbers to achieve his desired results, and his report has vague or non-existent references (but lots of footnotes). This appears to be an attempt to create a patina of respectibility for his calculations while obfuscating his methods, but I don’t know for sure.
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. His recent work simply confirms this conclusion. 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. This sorry episode does not make me optimistic for our ability as a society to deal with complex issues like climate change in the 21st century unless we change the way media reporting is conducted on technical issues.
