The RPi boards aren't the best choice for low current consumption, even other competing but similar ARM boards are better suited for that use. However, the main

The RPi boards aren't the best choice for low current consumption, even other competing but similar ARM boards are better suited for that use. However, the main processor is just one of the power hungry devices: a LED screen needs its backlight on to be read, while an e-paper screens don't, and their power consumption falls to zero when the user is reading a still image, which also allows the processors to enter in extremely low power sleep modes. Making a reader with LCD/LED displays in my opinion is doable, but tuning the power consumption to save as much power as possible will require a lot of effort, and would never compare to e-readers anyway. However, if one accepts a heavier and more thick device, then yes, it's definitely doable, and could also become a better platform for other uses too.