Microsoft Chairman Bill Gates delivers r

Microsoft Chairman Bill Gates delivers remarks on the state of energy February 28, 2012 during the US Energy Department’s Advanced Research Projects Agency-Energy (ARPA-E) Energy Innovation Summit at the Gaylord National Hotel & Convention Center in National Harbor, Maryland near Washington, DC. Gates was joined by US Energy Secretary Steven Chu and former White House Chief of Staff John Podesta. AFP Photo/Paul J. Richards (Photo credit should read PAUL J. RICHARDS/AFP/Getty Images)