There are cases where a relatively maintenance free power source which can be installed a point of use is worth a lot more than you'd think -- it's basically like a primary battery cell -- a way to transport energy. It doesn't matter if it's less than unity efficient in recovering the power used to make it, if distribution and storage costs for that power would otherwise be really high.
On cellphone towers in the middle of nowhere with no wirelines linking them, a solar panel makes a lot of sense, even if it never recovers as much power as it cost to build. Or on a satellite. Or, apparently, on a shack in rural Africa.
I agree Africa probably could do better with natural gas, oil, hydro, or coal central plants for now, vs. big solar plants, but a combination of cheap big grid power sources and decentralized renewables seems like the best solution. Building out a grid in rural areas isn't really cost effective.