Got a smartphone? Take a look at it. Think “refrigerator.”

That’s because a smartphone consumes more energy than a fridge. When I read this, in an article on Grist.org, I had a hard time a believing it. (Grist in turn links to this technical report, The Cloud Begins with Coal.)

What about all those functions that an iPhone replaces? They use energy, batteries … isn’t there some significant energy efficiency there?

Fortunately, we have an expert on ICT and energy use in the AtKisson Group, Kate Ognessian, who is finishing a PhD on the subject at Mendeleev University in Moscow.

Her analysis was compelling … and distressing.

Here is what I wrote to Kate:

One question that struck me, which you are the right person to ask:  certainly there must be some efficiency gains from the concentration of functions in these devices. For example, my iPhone has replaced …

– My camera
– Flashlight
– Guitar tuner
– Personal music player (remember Walkman?)
– Voice recorder (I used to have one of those with me for interviews, or working on songs)

… and maybe one or two other devices, all of which required batteries to operate.

This makes the analysis even more complicated. These functions now “count” as ICT electricity use … even the flashlight!

But since I no longer have a camera whose batteries need to be charged, there is some efficiency gain in that concentration of functions.

Or … is this already well studied etc.?

Kate replied:

Ha, that’s a very interesting issue.

I would agree that you realize such energy efficiency thanks to concentration of functions only in the case that each of your devices has to be charged each day or two. I did not make exact calculations but I suspect that AA or AAA batteries for Walkman, flashlight and other devices with non-continuous use were much more efficient. Modern cellular phones have two main features that consume energy: the touchscreen as it is (consumes a lot, even when it’s dark) and the permanent connection with base station (even if you don’t call, the phone exchanges signals with the nearest base station).

Here is an immediate comparison I made according to my own experience:

Apple iPhone: 1 Sim, touchscreen, usual style of use, to be charged almost each day (max every 2 days).

Philips Xenium x623: 2 active Sims, no touchscreen, usual style of use, to be charged once a week or 10 days.

Old cassette Walkman: 2 AA batteries per 6 hours of music, battery change each week.

Digital radio receiver: 1 AAA battery per 20 hours of music, battery change each 10 days.

Flashlight: 2 AA batteries, battery change once a year (!)

Voice recorder (I also use it :): 1 AAA battery, change before each session – about 1 piece per 3 month.

I can add also my mother’s E-book reader (E-ink technology): to be charged once per month (reading about 2 hour per day).

For a user like me (with digital radio receiver, voice recorder and flashlight) we can refrain from using 40 AAA and 2 AA batteries per year thanks to the concentration of functions, but instead you have to do at least 300 cycles of charging your iPhone.

Kate then takes the analysis ever further (e-book readers beware, there is bad news in here for you, as well):

My first cellular Nokia (year 1999) with its original battery was able to maintain 4 hours of conversation while 6 AA batteries maintained only 0.5 hour. Proportion was 1 phone battery capacity = 48 AA. iPhone battery has several times (at least 3-5 times, maybe even 7) bigger capacity than old Nokia. But iPhone spends all the energy within 1 or 2 days! 48 AA x 3 times x 300 days = 43200 AA batteries per year, and that’s a _very modest_ estimation. I would say 75 000 or more. Do you see any efficiency?

Take into account that any phone charger connected to an electrical socket consumes energy even when the phone is disconnected, so don’t keep charger connected to the socket when it is idle! And after about 100 cycles of charging, the battery capacity starts to decrease. If you have a touchscreen phone, you will need to change batteries after 1-1.5 years of usage.

By the way, I’ve read that e-book readers become energy efficient [relative to actual books] only if you read more that 53 thick books per year. I guess if they took into account recycling expenses for the gadget … [that would expand the number further.]

So … take another look at that iPhone.  Think, “refrigerator.” Only worse.  (Thanks, Kate! I think …)