There are many obvious sources of clean energy innovation. But lately the clean energy community has begun paying attention to one not-so-obvious source: the Department of Defense. With a massive energy footprint and a mission-driven need to reduce fossil energy consumption, DOD can play a prime role accelerating cleantech development and is already seeking to become a test bed for innovative technologies. At stake is not national security but also economic security. In a report unveiled at an event March 31 on Capitol Hill with lawmakers, DOD officials and industry leaders, ITIF provides a comprehensive review of the important energy innovation activities at DOD and lays out the indispensible role of public investment and public-private partnerships to spur transformational technologies. The event was sponsored by ITIF, the Information Technology Industry Council, and the Digital Energy Solutions Campaign.