“Since the beginning of the electric grid, utilities have placed most power plants close to America’s rapidly growing cities, because it was relatively easy to use railroads and pipelines to ship fossil fuels from wherever they were extracted to the power plants where they’d be burned to make electricity. As a result, America’s power grid relies on railroads and pipelines to move fuels over long distances to power plants, and then on transmission lines to move electricity over short distances to the cities that need it. That model doesn’t work with solar and wind. You can’t ship sunlight in a railcar to some power plant; it has to be converted to electricity on the spot. But most of America’s sunlight supply is in the Southwest, and most of our wind is in the Great Plains, far from many major urban areas.”