Solar power is hot on the heels of fossil fuels. In 2013, residential, nonresidential, and utility-scale solar installations in the United States added 4,863 megawatts of electricity to the nation's generating capacity, second only to natural gas, at 6,861 megawatts. (Left in the dust, appropriately, was coal power, at 1,507 megawatts.) Through the first half of 2014, 53 percent of all new electric capacity installed came from solar power.