Applying some imagination, I guess you head to your local internet/phone cafe and charge the thing before heading home, or you or your village have something like this:
some imagination is expected from MS not the poor people without electricity, and without the luxury of imagination. This is a typical example of senseless marketing. If you are targeting the 20% mentioned, i would expect a Solar panel based charger that would charge a battery during the day, and then transfer the stored energy to the phone during the night. Now that's the imagination i would love to see.
http://amzn.com/B00CTDW5TA