What is a zoo to do with its excess panda poo? Denver's answer is to compress it into pucks and feed them to a syngas-powered hybrid-electric Tuk Tuk.
It appears that brown is the new green. The Denver Zoo has decided to make use of all that primo animal poop that comes out of its residents and convert it into fuel. Now you can tour the zoo (and enjoy a frozen margarita) with the aid of this poo-power.