Ethanol ventures backed by billionaire entrepreneur Vinod Khosla — including Range ?Fuels, which built a failed factory in Georgia — were given the green light for an estimated $600 million in federal and state subsidies, according to an analysis by The Atlanta Journal Constitution.

Yet none of the dozen or so companies financed or controlled by Khosla over the last decade has produced commercially viable ethanol. Some failed or, hamstrung by unproven technology and insufficient capital, remain behind schedule.