Atlantic Cities: It`s a little after sundown, and Arun Kumar is hawking his wares in the neighborhood for the first time. He`s selling a light, just a small half-circle tied to a three-inch-wide solar panel. An older man tests it in his home, a tiny hut of tarp and tin built like the 30 others in this slum settlement on the far north side of Bangalore. A kerosene lamp flickers inside.
At a second home, Arun wields his 1,600-rupee ($29.48) gizmo for a woman seated with nine children. He points out the small cellphone...