✏ Long term power for the Fairphone 2 (solar?)

[Sonne]

Concerning the solar panels:

Continuing the discussion from Potential for a solar panel under the transparent back cover?:

@marc_bamberg

maybe check this out:
it is a solar battery charger with 3rd generation flexible solar cells. Not cheap, no doubt, and another story where you have to wait for your product. But it is really awesome, I think. Another fair use story, maybe.
crowdfunding page link

https://www.kickstarter.com/projects/infinitypv/heli-on