Much of the world lacks what Germany (and Europe in general) has: industry. You can supply industry using solar, because it is needed during the day mostly. Yes

Much of the world lacks what Germany (and Europe in general) has: industry. You can supply industry using solar, because it is needed during the day mostly. Yes, the output in winter is 10x smaller, that's why we need also other power sources (at least until we have a way to store electricity effectively). What's the purpose of solar farm in Sahara? Lack of a need for electricity (except AC, but not many there can afford it) and transferring power over long distances is not effective. For home heating there are other energy sources, not as clean (well maybe except wind, which blows during winter also): coal, gas, oil and nuclear.