The United States faces important decisions about future energy supply and use. A key question is how renewable energy resources might be used to meet U.S. energy needs in general, and to meet U.S. electricity needs specifically. This book provides a summary of U.S. electricity generation potential from wind, solar, geothermal, hydroelectric, ocean-hydrokinetic, and biomass sources of renewable energy. An assessment of U.S. renewable electricity generation potential and how renewables might satisfy electric power sector demand is discussed, as are the challenges, issues and barriers that might limit renewable electricity generation deployment.