Harnett County farmer uses hog waste to create renewable energy


One Harnett County farmer is investing in a new energy source — hog waste.

Farmer Tom Butler of Butler Farms, located an hour southeast of Raleigh, traps methane gas, a byproduct of hog waste, in order to create renewable energy.

“We decided to see if we could take that methane and turn a waste into an asset,”said Butler.

Butler has roughly 8,000 hogs on his farm, which produce about 35,000 gallons of waste per day. The waste can pollute the air and water, and produce the byproduct methane gas.

Though methane is a form of natural gas that can generate heat and electricity, if it escapes, it acts as a greenhouse gas 20 times as destructive as carbon dioxide.

Most hog farmers keep the waste in open pits called lagoons, where the methane escapes. UNC professor Mike Aitken says the farm industry has not adopted technology to deal with this pollution.

“We still manage most waste, including hog waste, in a way that we were dealing with human waste over a century ago. We have never entered the 20th century with animal waste management, never mind the 21st century,” said Aitken.

Butler’s 21st century approach involves trapping the methane gas from the lagoons. By trapping the methane, Butler uses his lagoons to create renewable energy he can sell or use on the farm.

Methane from the lagoons is trapped under tarps and transported through tubes to a generator room. The generator burns the methane to create electricity.

Though this method reduces greenhouse gas emissions and provides renewable energy, Butler says many farms do not use the method because of the cost.

Butler’s system costs more than half a million dollars to install, but he says wider use of this technology will lessen its cost.

Butler says he hopes his farm can provide an environmental model for other farms.

“If we can keep from putting greenhouse gases in the atmosphere, why not? And it’s a commodity you can use here on the farm,” said Butler.

By selling his electricity, Butler makes $28,000 per year and says he expects that profit to grow.


Written by Dan Lane, News 14 Carolina