Oslo, Norway has rolled out a bus fleet that is powered in part by human waste product. Treated human sewage is converted into a product called BIOGAS, which is what the buses run on. One trip to the bathroom could potentially power a bus to move 40 meters.
According to wikipedia, BIOGAS is produced by anaerobic digestion/fermentation of biodegradable materials such as biomass, manure, sewage, municipal waste, green waste, plant material, and energy crops. The gas produced is comprised mostly of methane, which is the principal component of natural gas.
Compared to diesel buses, these BIOGAS buses emit 70% less NOx and 98% less Particulate Matter (PM). NOx and PM are two out of the six so called “common air pollutants” identified by the US EPA via the Clean Air Act that the agency has to set National Ambient Air Quality Standards (NAAQS) for.
Watch the video here.