I really wanted an iPad. I had good reasons to get one, too, but I couldn’t afford an iPad for a long time because all my money was going into my basic costs of living. (It was embarrassing that I couldn’t afford one, and that’s why I didn’t blog about it until now.)

I had an iMac for my computer, but that’s not portable like an iPad. And I wouldn’t just be reading with it; I’d be surfing, e-mail communication, document/project work and writing. I could use a bluetooth keyboard instead of the built-in screen keyboard.  The keyboard requires a pair of AA batteries recharged once every two months.

While I was hankering after the tool, I even did a cost-benefits-counterargument analysis trading the use of an iPad off against my cell phone service ($430 cost vs. $40/month) and the cost of electricty. And as soon as I could finally afford to, I went and got an iPad 2,  with 64 Gb, Wifi + cellular, in order to make it as useful to me as it could possibly be for as long as it lives.

People have raised the environmental virtue question about using an e-reader rather than paper books; the carbon footprint of an iPad itself is equal to that of 40 books.  I have a very low carbon footprint when it comes to books anyway because I’m devoted to the library.

When I had a laptop, I wore out the battery and had to get a replacement. That’s how I learned that there’s a finite number of cycles that batteries get, so it’s best to only rely on the battery when you need to – and use it until its battery is completely flat at least once a month – and then recharge it to 100% before using it again, to keep it trained. If you are often in the situation where you need to watch your battery charge, here’s an article on apps to extend your battery life.

Why do I care about this? A story:

I did not have a cell phone until late 2005 by choice because mining coltan kills African wildlife. (In fact, though Africa needs trade, whenever the trade comes from outside the African continent, it seems to bring nothing but degradation and injustice.) Coltan miners – and other kinds of mining and exploitation – enjoyed their hunted beast barbeques, so they brought the habit back to the cities with them. Now Africa has a ridiculously “thriving” bush-meat trade, which means the animals are not thriving, on many fronts.

The life of your electronics is a problem: the thinner we like them, the more compact and fragile they become, and they cannot be recycled. Though they are small, a lot of resources go into making them.

The batteries in our cell phones and laptops and electric cars are based on a heavy metal that must be mined. And so far, these batteries ARE NOT recyclable. Lazy people throw them in the garbage, but everyone else knows to put them out for special e-waste collection. The batteries are being stockpiled so that a future technological fix can efficiently recycle them, or safely dispose of them.

So please, start being conscientious about battery life and the lifespan of your electronics. Buy with a long view. Consider it like nuclear waste: a permanent harm, needing very costly storage.

The bright green environmentalist in me suspects that there are people who are working on this problem right now, but please see the note at bottom of this post. My inner dark-green environmentalist notes that the more we become enamored with gadgets and comfort, the less notice we take of nature and our needs to live within it.

Calculating the electricity cost

Charging an iPad on a 10 or 12-Watt adapter costs very, very, very little.

  1. Multiply the 10- or 12-W charge by 3 hours per charge = 30 to 36 Wh.
  2. Compare this power draw of using a computer with a 200W power supply (average †) x 3 h = 600 Wh or 0.6 kWh 
  3. Divide 600 Wh ÷ 36 Wh = 16.6666 times more electricity used with the computer than the iPad
  4. Except that the iPad has a battery life of 10 hours vs 200W for 10 hours: 2kWh ÷ 36 Wh ≈ 55. That’s a 55-fold difference in electricity usage over 10 hours a day.
  5. Or, if you consider that the 3 hours of charging time were also used productively: 13 h x 200W = 2.6kWh ÷ 36 Wh ≈ 72 times more electricity for a 13 hour period of using a desktop over an iPad.

† I read on an Apple discussion that the power consumption for 27-inch iMac (mine is 20-inch) is 200 W from 100V-115V-230V currents. I had a PC tower at one time with a 300W power supply. Technology reports at the time said that computers too often turned off would suffer from a mysterious condition called “creep,” so I ran it all day, all night.

Now consider: when I was making these cost-benefit calculations, I was using the iMac to broadcast my home’s WiFi signal for 16 hours a day. (It went to full sleep at midnight.) As the Apple discussion noted, the ghost power when the iMac is off is 0.85W per hour (or 0.88W-0.90W), and when in Sleep mode, it’s 1.44W (or 1.42W-1.53W).

Now that you’re aware how to do the simple math of the energy your gadgets consume, do your own comparisons. With my above assumptions converted into 365 days per year, energy cost worked out to less than $1 per year for the iPad, and $55/y for the iMac. That’s…not outrageously expensive for the latter, but when compared to the former… obvious which device to prefer for most surfing and email!

I am confident that working on the iPad while sleeping the Mac is saving a lot of power. Since replacing my WiFi router, that’s a much smaller power draw than before. Now, I only wake the iMac up for things to do on the big screen with a mouse and keyboard. Over the course of the next 5 to 7 years – the expected lifetime of the iPad – the electricity I save will surely pay back part of the iPad’s price .


The Note I promised you

The dark green side of me says: don’t count on that shiny bright green future where we’ve solved our waste problems and respect the perimeters and depths of nature. We have long had the possibility of a waste-to-materials cycle, but have rarely made the choice to value it. Cargoism, the faith that technology solves all limit problems, is just as dominant a fantasy as growth economics. Humans do not voluntarily solve problems that we can simply walk away from. This is especially true when there are businesses and industries who profit from mining and mineral extraction, municipal waste, and environmental degradation has no direct cost. 

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