Global environmental challenges
Cow manure to combat global warming?
A study by scientists in Texas reckons that cows, sheep, pigs, chickens and other farm animals excrete enough waste to generate electricity for millions of homes, helping reduce reliance on coal-fired power plants and so cut greenhouse gas emissions released by burning fossil fuels.
Left to decompose naturally, manure emits the powerful greenhouse gases methane and nitrous oxide. If trapped by a devoted workforce (people with an impaired sense of smell encouraged to apply) the gases could used to drive microturbines to generate electricity. That works by the manure being “anaerobically digested” — a process a bit like making compost — to release energy-rich biogas which would be burnt to drive the microturbines.
The calculations, the scientists say they are the first to outline a procedure for quantifying amounts of energy and greenhouse gases linked to national herds, suggest that farm animals in the United States alone could generate about 2.4 percent of U.S. electricity and avert about 3.9 percent of greenhouse gas emissions.
Dung is widely burnt in the Third World as a fuel; why not exploit it elsewhere?
The study doesn’t look into the uncertainties about the economics of sucking up manure, transport, building specialised power plants, etc (with oil at almost $130 a barrel, what would you pay for a barrel of manure?)
So, if you live in the countryside and your eco-minded neighbour tells you sometime in future: “We switched our electricity supplier from coal to get it from the local wind farm” you can go one better and say:
“See Daisy the cow over there in the field? We get ours from her”.
Is there a future for manure?