Renewables receive a disproportionate share of media coverage given their still small size. In 2019, less than 9% of America’s power came from solar and wind. Fossil fuels (mainly coal and natural gas) are over 62%. Moreover, electric power is only 37% of our total energy use. Renewables receive outsized attention because of the hope they will lead to lower emissions. A look at recent daily data on U.S. power generation illustrates the challenges we’ll face in relying on intermittent, low-density sources of energy.