here is my contribution for solar powered RPI projects.
using a raspberry Pi for small projects that are solar powered you can use a powerbank with pass through charging for powering the RPI.
the power path can be
solarpanel --> powerbank --> RPI 1/2 /3 + wlan stick
requirements
solarpanel
voltage 5V / current 2A / power output 20W, monocrystaline Modules
for example SunPower Modules with USB connector
powerbank
voltage 5V / current 2A / capacity 20Ah
advantages
- ups function for RPI
- the RPI works 24 hours a day powered by the powerbank
- the solarpanel delivers power that can be saved in the powerbank
possible solarpanel
RAVpower 24W Solar Charger
possible powerbank
RAVpower 22Ah Powerbank
with a usb multimeter you can measure the power output of the solarpanel
USB multimeter
