U.S. Secretary of Energy Steven Chu (C) listens to students Allison Kopf (L), Annessa Mattson (2ndL) and Tim Sennott (R) describe Team California's solar-powered house during the 2009 U.S. Department of Energy Solar Decathlon on the National Mall in Washington October 7, 2009. Reuters Pictures logo Reuters Pictures 28 months ago

U.S. Secretary of Energy Steven Chu (C) listens to students Allison Kopf (L), Annessa Mattson (2ndL) and Tim Sennott (R) describe Team California's solar-powered house during the 2009 U.S. Department of Energy Solar Decathlon on the National Mall in Washington October 7, 2009.