Here's a video from the World Wildlife Fund. Traditionally, anaerobic digester systems have not been practical on small dairy farms, but this didn’t stop Sensenig Dairy, a 100-cow farm, from pursuing its goal. Then Sensenig teamed up with the local community to collect enough waste to produce 1,401,600 kilowatt hours of electricity per year from "trash" that would otherwise end up in a landfill.