In 2005, the National Research Council report Rising Above the Gathering Storm recommended a new way for the federal government to spur technological breakthroughs in the energy sector. It recommended the creation of a new agency, the Advanced Research Projects Agency-Energy, or ARPA-E, as an adaptation of the Defense Advanced Research Projects Agency (DARPA) modelâ€"widely considered a successful experiment that has funded out-of-the-box, transformative research and engineering that made possible the Internet, GPS, and stealth aircraft. This new agency was envisioned as a means of tackling the nation's energy challenges in a way that could translate basic research into technological breakthroughs while also addressing economic, environmental, and security issues. Congress authorized ARPA-E in the 2007 America COMPETES Act and requested an early assessment following 6 years of operation to examine the agency's progress toward achieving its statutory mission and goals. This publication summarizes the results of that assessment.