Elephant-poo power electrifies zoo

At Munich Zoo, they take animals' dungs, mix with warm water and bacteria and left it there about 30 days. The result they get is biogas, mainly contain methane and carbon dioxide, which they can turn it to the electricity and heat that they can store, use to warm the gorilla enclosure or they could be used to heat about 25 homes. when the fermentation complete, it create methane  the remaining solid matter, or "digestate" is used as an organic fertilizer for crops."It's really important that we change our mindset from dependence on one source of energy to many different complementary sources," Evans said. "Animal waste can create electricity, heat, fertilizer ... even clean water can be extracted from the solids to spray on crops.