The Department of Energy (DOE) is a U.S. government agency responsible for advancing the national, economic, and energy security of the United States. It focuses on scientific research, energy production, and nuclear safety. The DOE oversees the national laboratories, conducts research in physical sciences, and manages the country's nuclear weapons program. Established in 1977, the department plays a crucial role in driving innovation in renewable energy technologies and ensuring the environmental cleanup of the national nuclear weapons complex.