There's a ycombinator startup that builds battery/mobile phone recharging stations in Africa - http://disrupt-africa.com/2017/10/senegalese-solar-startup-o...
Combine a sealed tablet with solar recharging and an OTG keyboard, you should have a much better system than a laptop/desktop. You can also protect the tablet using a shockproof case. A 10 inch octacore tablet with 4gb ram and LTE capability costs 80$ shipped on aliexpress to anywhere in the world.
Interestingly there's an app that replicates a desktop-y wordprocessor on an Android tablet and has specific compatibility for keyboards
https://play.google.com/store/apps/details?id=softmaker.appl...