Endless potential. (2009). National Geographic, 216(3), 40-41.Several diagrams and maps are presented regarding the potential that exists to generate electricity using solar power including a diagram ranking the electrical output of various renewable energy sources such as wind, tidal, and geothermal, a map showing where the largest percentage of the solar radiation hits the Earth surface, and a map of the southwestern U.S. showing places where solar radiation is suitable for use.