Storing cleaner energy is vital to reducing heat-trapping air pollution from the burning of fossil fuels. Tech company ...

D.Light, a company that originated as a project at Stanford's design school, wants to solve that problem: They just made the world's cheapest solar lantern.

In this explainer series, we'll dive into the surprising stories behind how businesses work--exploring everything from Costco's "treasure-hunt" model to the economics behind Amazon's AWS.