EInk on a phone. Maybe with Project Ara

I have been talking about EInk with a buddy of mine for months.  I want a phone that supports an EInk display.  Obviously an EInk display will not work 100% of the time, but if you could hot-swap the screen.....like with Project Ara....then you could have an awesome set.  This topic was recently brought up on reddit.  I am not the only crazy one that wants an EInk display for a phone.

I see two major benefits for having an optional EInk screen on a phone.  The first is battery life.  Out of all the components in your phone (antenna, process, RAM) your screen takes up the most battery.  EInk displays only require battery when the contents of the screen change.  This is why they are great for e-Books.  You spend a little electricity to change the screen to display words.  Once the words are visible, the screen no longer draws electricity.  If you have an EInk display on your phone, then turning on your screen is no longer a big deal.  You obviously can't play games, but it is good enough for email, SMS and phone calls.

The second major benefit is using your phone outside in the daylight.  LED displays are sometimes hard to see in sunlight.  You often have to bump up the brightness just so you can see the screen, taking up even more battery.  With an EInk display, you can use your phone outside again!

The question becomes how do you put an EInk display into a phone.  The Yota Phone 2 puts an EInk display on the back of the phone, so all you have to do is spin the phone and switch which display gets used.  There was a Kickstarter for a second screen that attaches to your phone.  This screen is awkward and not very compatible.  I think the best bet is with Project Ara.  With Project Ara, you could in theory hotswap the screen with one that uses EInk.  I can't wait for Project Ara to be released.