As we drove through the hilly acreage behind Joel Wolf’s ranch, his cattle shading themselves beneath stately old oaks, he gushed about the scale of the potential. “Cars are just the start! Tractors, generators, stationary pumps — agricultural equipment runs on diesel. As do ships. All that could run on vegetable oil.” We passed a wide patch of black crude seeping out of the ground, then an oil well, then a grove of dark walnut trees whose fruit, if pressed, could go in the tank of the truck we were driving. I asked Joel if he thought of harvesting his walnuts for that purpose. “Not yet,” he answered. “But they’d probably burn real nice.”
