We've known for over a century that bacteria can generate electricity. But now, we can put that knowledge to use and turn each toilet flush into a potential source of energy.
Chicago and its outlying suburbs create 1.5 billion gallons of wastewater every day. Since this isn't the 1880s anymore and you can't just let the effluence run back into Lake Michigan, you've got to clean it. Here. At the biggest wastewater treatment plant on Earth.