A three-wheeled rickshaw powered by animal waste, courtesy of the Denver Zoo.
The Denver Zoo unveiled a poo-powered tuk tuk this week, the first of its kind. It's part of an almost decade-long effort to use the zoo's waste for good. As a Denver Post article explains:
This idea — which is now patent pending — began eight years ago during the early planning for the Elephant Passage. Cutting down energy use was a priority, and as a result, a three-person engineering team was commissioned to develop alternative options. It started with consumption analysis.
"These guys spent a lot of time in Dumpsters figuring out what kind of trash we produce," Barnhart said.