Most of the developing world doesn't have a grid today. Building microgrids powered by small clean energy resources is much cheaper than building a grid. Now this is only true at modest per-capita electricity consumption amounts, but that matches the wealth available in a lot of places.

On a very small scale, that's why you see solar-powered flashlights being so popular in rural areas of the developing world. And my favorite charity (kickstart.org) is currently designing a solar-powered water pump, as a step up from their current human-powered water pumps.