I think you are referring to this study: http://blog.opower.com/2012/09/how-much-does-it-cost-to-charge-an-iphone-5-a-thought-provokingly-modest-0-41year/ http:

I think you are referring to this study: http://blog.opower.com/2012/09/how-much-does-it-cost-to-charge-an-iphone-5-a-thought-provokingly-modest-0-41year/ http://blog.opower.com/2012/09/how-much-does-it-cost-to-char... Which has the iPhone 5 at $0.41/y, the Samsung S III at $0.53/y and the iPad (model unclear, but I guess the 3), at $1.36. I agree with your point though: the electricity cost of these devices is already negligible, an e-ink display wouldn’t make much of a difference.