I just searched for Solar chargers for ereaders.
I found 2 types: Panels only (USB outlets) and battery Packs.
The size/and weight determines how fast things happen.
To put things in perspective: A standard Computer USB2 port is limited to 1/2A (500ma). If you spend hours relaxing in the sun (or a shade in the sun), the a light weight panel (<US$25) is all you need for just your reader.
The more stuff, the bigger capacity. Want power at night, then a battery pack model.
Want your Coffee Brewer, then @Renate size panel may work if it has a large battery.
BTW I am very suspicious of some YouTube ads, claiming what a 25lb solar generator can power. Start a circular saw, OK. But cut much of anything

A KWh is 1 Killowatt for 1 hour. Do your maths