LAS VEGAS, NV – SEPTEMBER 04: President of U.S. Operations for UPS Myron Gray (R) speaks as Agriculture Secretary Tom Vilsack looks on during a news conference at the National Clean Energy Summit 7.0 at the Mandalay Bay Convention Center on September 4, 2014 in Las Vegas, Nevada. The U.S. Department of Agriculture (USDA) announced that it closed on a loan guarantee to Fulcrum Sierra Biofuels to build a refinery in McCarran, Nevada, to make jet fuel from municipal solid waste. UPS has committed to buy the fuel for its fleet of aircraft. Political and economic leaders are attending the summit to discuss a domestic policy agenda to advance alternative energy for the country’s future. (Photo by Ethan Miller/Getty Images)