The United States has abundant solar energy resources and solar, along with wind, offers the greatest energy and power potential among all currently available domestic renewable resources. Additionally, federal interest in batteries and other energy storage technologies has increased in recent years to help address energy, defence, and space exploration challenges. The federal government has devoted substantial resources to support such technologies for the electric grid, electric vehicles, war-fighting, and other uses. This book provides an overview of federal initiatives supporting solar energy, batteries and energy storage, with a focus on the potential for fragmentation, overlap, or duplication, as well as the extent of any coordination among these initiatives.