Starting in 2010, the streets of Oslo, Norway, will see the rollout of city buses run using biofuels derived from human waste.
Methane will be generated from sewage sludge fermented in giant tanks. The methane powered buses will be carbon neutral and will emit 78% less NO2 and 98% fewer fine particles than traditional diesel buses.
Ole Jakob Johansen, one of the people pushing poop power in Oslo, said that each person creates the equivalent of 2.1 gallons of diesel fuel per year by visiting the bathroom. Multiply that by a city of 250,000 and you can operate 80 buses for 62,000 miles each.
The methane will cost less than diesel, though the buses will be more expensive to buy and maintain. If the plan is expanded to include Oslo's other waste treatment plant, planners think they could eventually power the entire Oslo bus fleet -- 350 to 400 buses.
One of the big issues surrounded traditional bio-fuels (at least corn-based fuel stocks) is that they divert food from mouth to gas tank. Instead of growing food to turn into fuel, Oslo is adding in a step and catching the bioenergy after the food is eaten (and dropped off at "the pool").