Interesting research on stretching the most we can out of our coffee is described by Mano Misra at the University of Nevada. Misra was part of a team to extract fuel oil from used coffee grounds. The process they used, which the researchers are holding tight to their chests for now, resulted in leftover solid material from the original coffee grounds, which could be composted in a garden to add to the growth of food, providing energy directly to an alternative form of transportation – walking.
The burning of the coffee-derived fuel could be a good supplement to gasoline and other fossil fuels, but would still produce emissions of carbon dioxide and other pollutants, contributing to climate trouble. It has also yet to be determined whether the energy expended in the creation of fuel oil from coffee grounds would be less than that provided by the coffee oil itself.