'Poop to power' program turns pig manure into sustainable energy

January 9, 2012 By By John Platt

The nearly 9,000 hogs at Loyd Ray Farms in Yadkin County, N.C., produce 400,000 gallons of manure every week. Since the waste had too high a nitrogen content to be used as fertilizer, owner Loyd Bryant used to pump that waste into a local lagoon, where it released methane, ammonia and "an unholy stink," according to the Los Angeles Times.

But now all of that is going to good use. Thanks to Duke University's new Carbon Offsets Initiative, the 154-acre farm now gets half of its electricity from a new waste-to-fuel system that has also solved the environmental problems caused by the . It reduces emissions from the waste, improves the health of Loyd's hogs, and creates a fertilizer he will use to grow corn, wheat and beans.

According to the Carbon Offsets Initiative website, the waste-to-fuel project "collects methane generated by hog waste and burns it to support the operations of the innovative system and create electricity for use on the farm. The destruction of the methane - a greenhouse gas 21 times more potent than carbon dioxide - creates GHG () offsets, and the renewable energy generated by the system creates renewable energy credits."

The $1.2 million system was the first full-scale offsets project completed in the Carbon Offsets Initiative. It was funded by Duke University, Duke Energy and Google - the university and Google will get carbon offset credits from the system - and was made from off-the-shelf parts and freely available designs.

The system "is not overly complicated and stands to yield many more benefits beyond and environmental protection," Tatjana Vujic, director of the Initiative, told the Times. "Farmers like the idea of using every bit of what comes off their farms. They can manage their waste and save money while doing it."

The system has several components. First, the hog waste is placed in an anaerobic digester, which contains bacteria that consume the manure and release methane gas. The methane is then burned to power a 65-kilowatt microturbine, which generates electricity to power support the entire waste management system and much of the farm's normal operations. After the manure is processed in the digester, liquid waste enters an aeration bin, where it is treated for ammonia and other pollutants. The resulting water can be used for irrigation or for flushing out barns. By the time the system is done, it has met all of North Carolina's environmental standards for reduction of odors and emissions.

"It would sound pretty crazy at one time, but we see it works," Bryant told local station Fox8 in October.

Under North Carolina law, the state's utilities must get 0.07 percent of their electricity from hog waste beginning in 2012 and 0.2 percent by 2018, the same amount it must generate from solar.

Explore further: Study nixes hog waste alternatives

Related Stories

Study nixes hog waste alternatives

March 8, 2006

A $17.3 million study in North Carolina seeking alternatives to open-air ponds used to treat hog farm waste has ended without success.

Methane from microbes: a fuel for the future

December 10, 2007

Microbes could provide a clean, renewable energy source and use up carbon dioxide in the process, suggested Dr James Chong at a Science Media Centre press briefing today.

Chicken waste turned to watts

December 26, 2009

A Nevada energy developer says it has developed an environmentally clean way of using animal waste from chicken farms across the state to light up homes and offices. Green Energy Solutions wants to convert the bird droppings ...

Chinese dairy harnesses cow-pat power

November 25, 2010

A Chinese dairy farm is installing the world's largest system to turn steaming cow pats into enough electricity to power thousands of homes.

Hog waste producing electricity and carbon offsets

September 8, 2011

A pilot waste-to-energy system constructed by Duke University and Duke Energy this week garnered the endorsement of Google Inc., which invests in high-quality carbon offsets from across the nation to fulfill its own carbon ...

Does converting cow manure to electricity pay off?

October 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. ...

Recommended for you

Dutch create world's largest man-made wave

October 5, 2015

In a country where most people live below sea level, studying the oceans is a matter of survival. Now Dutch scientists have created the world's biggest man-made wave in a bid to prepare for the worst.


Adjust slider to filter visible comments by rank

Display comments: newest first

2.9 / 5 (8) Jan 09, 2012
This! Even anti-green me, I can support. Used cooking oil to bio diesel, as well. Neither one are energy sinks. Neither technology on Good Intentions and Unicorn Farts.
2.2 / 5 (11) Jan 09, 2012
Shootist, want to borrow my unicorn fart power generator? I ate all my unicorns and sold their hoofs for superglue.
3.3 / 5 (6) Jan 09, 2012
"This! Even anti-green me, I can support."

Actually, it doesn't need your support, thank you.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.