Old Dog Poop, New Tricks

San Francisco looks to harness the power of pet poop

Renewable energy is the sh*t. No, really. San Francisco Bay Area cities are aiming to generate no trash by 2020, and nearly 4 percent of San Francisco's residential waste is animal excrement. What to do with the doo? Turn it into methane and heat your home or cook your meals with it! (Um, ew.) In the next few months, a San Francisco sanitation company will be collecting feces at a busy dog park -- no doubt employees are jostling for the assignment -- and sending it to be digested by hungry bacteria. The resulting methane could theoretically be used in any natural-gas system. Some officials hope to see methane digesters in individual homes within a few years. While it's a relatively newfangled notion in the United States, some European countries already process poo into energy.