Here in the U.S., we're used to thinking about solar power as one of those happy eco-friendly things that we'd all totally be using except for the fact that it's so much more expensive than fossil fuels. In the developing world, though, it's exactly the opposite: solar power is gaining ground with 1.3 billion people simply because it's the cheapest way to go.
Let's just forget about the fact that fossil fuels are all extracted from the Earth by evil corporations controlled by evil states and that they do evil things to our atmosphere. The real problem with fossil fuels is that unless you have a ton of infrastructure already in place, getting, refining, distributing and using liquid fuel is stupidly inefficient and expensive. And we're not even talking about cars: millions of households in Africa rely on kerosene lamps to provide light at night, which is important because (among other reasons) it extends the amount of time with which people are able to work or study.
Kerosene, like any fossil fuel, is expensive. In fact, it costs twice as much to use a kerosene lamp as it does to use a small solar panel, battery and LED lights, and it's cleaner and safer at the same time. Plus, with a solar panel, you can charge your cellphone too, which otherwise might cost you more money since (in Africa) you might have to rent a charger.
There's a whole new industry springing up to meet this demand with cheap and efficient microsolar systems. For about $10, you can buy a solar lighting system that includes a 2.5 watt solar panel, two LED overhead lights and a battery pack. Every week, you pay a small fee (about $1) to use the power the solar panel provides (offsetting the subsidized up-front cost). After about 18 months, the system has been completely paid off, and you can upgrade it to a larger solar panel with more lights and battery capacity. Eventually, it's even possible to work your way up to a system than can run a sewing machine or a refrigerator.
All this time, you'd be helping to both save the environment and fund a green tech industry, but again, that's really not the point. The point is that sometimes solar power really does make the most sense, both socially and financially, and if companies can leverage this developing world market to help make solar power more attractive and affordable to those of us who are stuck living in the first world, everybody (in every world) might just come out a winner.