Cow power could generate electricity for millions

Jul 24, 2008

Converting livestock manure into a domestic renewable fuel source could generate enough electricity to meet up to three per cent of North America's entire consumption needs and lead to a significant reduction in greenhouse gas emissions (GHGs), according to US research published today, Thursday, 24 July, in the Institute of Physics' Environmental Research Letters.

The journal paper, 'Cow Power: The Energy and Emissions Benefits of Converting Manure to Biogas', has implications for all countries with livestock as it is the first attempt to outline a procedure for quantifying the national amount of renewable energy that herds of cattle and other livestock can generate and the concomitant GHG emission reductions.

Livestock manure, left to decompose naturally, emits two particularly potent GHGs – nitrous oxide and methane. According to the Intergovernmental Panel on Climate Change, nitrous oxide warms the atmosphere 310 times more than carbon dioxide, methane does so 21 times more.

The journal paper creates two hypothetical scenarios and quantifies them to compare energy savings and GHG reducing benefits. The first is 'business as usual' with coal burnt for energy and with manure left to decompose naturally. The second is one wherein manure is anaerobically-digested to create biogas and then burnt to offset coal.

Through anaerobic digestion, similar to the process by which you create compost, manure can be turned into energy-rich biogas, which standard microturbines can use to produce electricity. The hundreds of millions of livestock inhabiting the US could produce approximately 100 billion kilowatt hours of electricity, enough to power millions of homes and offices.

And, as manure left to decompose naturally has a very damaging effect on the environment, this new waste management system has a net potential GHG emissions reduction of 99 million metric tonnes, wiping out approximately four per cent of the country's GHG emissions from electricity production.

The burning of biogas would lead to the emission of some CO2 but the output from biogas-burning plants would be less than that from, for example, coal.

Authors of the paper, Dr. Michael E. Webber and Amanda D Cuellar from the University of Texas at Austin, write, "In light of the criticism that has been levelled against biofuels, biogas production from manure has the less-controversial benefit of reusing an existing waste source and has the potential to improve the environment.

"Nonetheless, the logistics of widespread biogas production, including feedstock and digestates transportation, must be determined at the local level to produce the most environmentally advantageous, economical, and energy efficient system."

Source: Institute of Physics

Explore further: New Indian government takes promising steps on agriculture, water and climate

add to favorites email to friend print save as pdf

Related Stories

Harvesting the power of big data in agriculture

Jun 12, 2014

Connecting with old friends? There's an app for that. Logging your fitness goals? There's an app for that. Making your farm more sustainable? There, too, is an app for that. In our technology-driven world, farmers, scientists ...

Does converting cow manure to electricity pay off?

Oct 13, 2011

Studies have estimated that converting manure from the 95 million animal units in the United States would produce renewable energy equal to 8 billion gallons of gasoline, or 1% of the total energy consumption in the nation. ...

Waste heat could keep cows cool and comfortable

Oct 23, 2013

The dog days of summer can be brutal for cows. When dairy cattle get too hot, it means reduced milk production, decreased reproductive activity and sometimes death – and for dairy farmers, lost income.

Recommended for you

'Shocking' underground water loss in US drought

15 hours ago

A major drought across the western United States has sapped underground water resources, posing a greater threat to the water supply than previously understood, scientists said Thursday.

User comments : 6

Adjust slider to filter visible comments by rank

Display comments: newest first

Doug_Huffman
2.7 / 5 (7) Jul 24, 2008
And of the pollution committed by the infrastructure to timely collect the cow poop?
GDM
4 / 5 (4) Jul 24, 2008
So, are you going to simply leave it in the field? Drive down Calif Hiway 5 near Coalinga for a sample of this.
gopher65
3 / 5 (3) Jul 24, 2008
Since most cows live out their entire lives in feedlots or in milking barns, collecting both their gaseous emissions (burbs and farts) and their crap isn't difficult. Some modern barns are sealed, and methane emissions trapped and burned to offset electricity or heating costs. Doing something similar with the crap itself shouldn't be difficult.
wfl
2.4 / 5 (5) Jul 24, 2008
More pies in the sky. Has any one studied the net increase in atmospheric carbon/methane that will from ingestion, digestion, and discharge from cattle? I suspect it is similar to the corn-ethanol cycle, that is significant.
gopher65
4 / 5 (5) Jul 24, 2008
Well, if the methane is being produced as a waste product, then this is just recycling. I certainly agree that you wouldn't want to grow the cattle industry just to create more methane! That would be a very inefficient way to create fuel.

I see this as having nothing to do with global warming, personally. Cows are a low margin business, and any increase in efficiency or sellable products means more money for the farmer. If that farmer can capture methane and use it to reduce his fuel bill, then that is good economics from his point of view. And if he can capture enough methane to sell, that is even better.

And as I said, methane capture (via sealed barns) is already moving into the mainstream for just this reason; it reduces the cost of cattle production, and that puts more money in the pockets of farmers (who really need it, for the most part).
Arkaleus
5 / 5 (1) Jun 08, 2009
Cattle manure is already a valuble supplimental source of income for cattle ranchers. If there's another way for our food producers to make moeny for themselves and their families, go for it.

As for the climate benefits, I doubt the tiny fraction of methane and NO2 that cow plops generate compared to other natural emissions is going to produce a "significant" effect on anything whatsoever, unless you happen to live near Colinga, CA.

If you ignore the attempts to connect yet another human activity to additional regulation and taxation, this is a good idea.