Creating a low-carbon future for the United States requires innovative clean energy technologies that are cost-effective compared to the fossil fuels the country has long relied on. The U.S. Department of Energy’s Advanced Research Projects Agency – Energy (ARPA-E) was established in 2007 to help achieve this goal by supporting the research, development and demonstration of potential breakthrough technologies. ARPA-E received $858.8 million in federal funding through early 2012, and supported 180 technology projects with $521.7 million of awards. Projects ranged from enhancing wind turbine designs to creating underground energy storage and improving carbon capture and storage technologies. Beyond direct support, ARPA-E awards have helped companies leverage more than $200 million in additional private investment. This brief provides an overview of ARPA-E and highlights of supported projects.