On a sunny morning in Toronto, an Indian rhino named Vishnu is using his horn to smash a barrel and get to the hay inside.
It's breakfast time at the Toronto Zoo, and the smell in this indoor pen is — well, ripe. One 8-year-old zoo visitor describes the odor: "I think it smells like whatever it's eating and whatever comes out the other end," he says.
He's right: Vishnu produces about 25 pounds of dung per day, not to mention what's produced by all the other animals at the zoo. “We have over 5,000 animals on site,” says Kyla Greenham, the zoo's curator of conservation and environment. “From our large mammals, we’re looking at about 300 to 400 animals, and that's why we can come up with 3,000 tons of manure a year.”
Now the zoo is coming up with a plan to turn all of that poop into power. It has partnered with a company called ZooShare to build a biogas facility that will produce electricity by harvesting methane from the animal waste. Along with the zoo's 3,000 tons of waste, it will also use 14,000 tons of organic waste from a large supermarket chain.