Poo Power

Talk about a cheap alternative energy source, each day visitors to the Cosmo dog park in Gilbert, Arizona, leave behind about eight cubic yards of dog waste, plastic bottles, bags and other trash.   Starting this month, however, that waste will be used to power a light at the park.  A team of engineering and technology students at Arizona State University's Polytechnic campus created a "dog waste digester" as part of their iProjects program. Patrons can deposit their dogs’ waste into an underground system, though specially designed openings, where it will be broken down through a process called anaerobic (in the absence of oxygen) digestion.  Biogas (a combination of methane, carbon dioxide, water vapor and other gases) is produced as a byproduct and used to generate electricity for the light.