A Contract with the Earth 10: Trash and Manure as Fuel

In my last reading of A Contract with the Earth, by Newt Gingrich and Terry Maple, I read that trash and manure can be used as a power source and are being used as such in some areas (or at least there were plans for that to happen when this book was written in 2007). I think that's cool. I remember the closing scene of Back to the Future, when Doc Brown threw trash into his fuel-tank to refuel the Delorian.