I disagree. Solar actually works best with a grid. A grid allows for pumped-storage hydroelectric, which is a lot cleaner and more reliable than thousands of battery banks. A grid also allows transfer of power from areas that are sunny to areas that are cloud-covered.
The goal should be to build out grids in Africa powered by clean power, whether it’s solar, wind, hydro, or modular nuclear.
Contrary to popular belief, cell phones actually require a “grid” and a lot of infrastructure. Range of digital phones is very limited, so you need a lot of antennae and terrestrial wiring to cover an area.