America's oil consumption far exceeds that of every other country in the world. What's more, it's unsustainable. Therefore, in 2007, Congress mandated a move away from petroleum-based oils toward more renewable sources. Soybeans, an important dietary protein and the current primary source of plant-based oils used for biodiesel production, only yield about one barrel per acre. At this rate, the soybean crop could never quench the nation's thirst for oil.