Biofuels, mainly ethanol, now account for one-tenth of car fuel consumed in the United States and that number is set to rise. But are biofuels the silver bullet for the looming energy crisis? Produced by Citlalli Sandoval and Lingzhi Jin. Guests include: Dogpatch Biofuels, San Francisco's only biodiesel gas station; Karl Knapp, Associate Professor for Stanford's Department of Civil Engineering; David Lobell, Associate Director of the Center for Food Security and the Environment at Stanford; and Eric McAfee, entrepreneur, VC and philanthropist in the renewables field.