At the end of the Back to the Future movie, Doc Brown returns to 1985 from a futuristic 2015. The first thing he does is fuel up his time-traveling DeLorean with a banana skin and a beer. Unlike the movie, 2015 did not bring trash-powered cold fusion (or flying cars). It's now 2020, and we still don't have those things. But, we do have transportation fuel made from all kinds of things, including trash and biomass.