Bloomberg: Power grids that work at a fraction of the scale of a traditional utility have gained support from banks and developers as a way to bring power to the 620 million people across Africa that lack access to electricity. From Kenya to Equatorial Guinea and Tanzania, companies including Italys biggest utility Enel SpA and General Electric Co. of the U.S. are building minigrids that distribute power to villages instead of whole nations. A plunge in the cost of renewables has opened a new source of power...