This 2001 photo shows a two-acre covered waste lagoon that harnesses methane gas in Johnston County, North Carolina. Credit: AP photo / News & Observer, Robert Willett

In the latest twist on the controversial power plant Duke University proposed last spring, an influential group of students, faculty and staff says it should be fueled from methane captured from hog waste, not natural gas.

“Duke University is committed to the investment necessary to utilize a percentage of biogas in the [plant] from day one of operation,” reads a fact sheet distributed at a community meeting last week on Duke’s campus in Durham, North Carolina.

The statement is one of several that’s garnered consensus from a select panel analyzing the 21-megawatt combined heat and power (CHP) plant, which is on hold following a firestorm of criticism from outside and within the Duke community about its purported climate benefits.

Throughout the controversy, the university has said it was a ‘long-range goal’ to convert the hyper-efficient plant from natural gas to biogas. But now the 23-member subcommittee says it should be fueled at least partially with swine gas from the outset.

“I think we can get enough biogas in this plant the day it fires so that it’s carbon neutral,” said the group’s chair, Tim Profeta, who also leads Duke’s Nicholas Institute for Environmental Solutions.

The subcommittee, which will report directly to the university’s board of trustees, has not yet finished its recommendations, and could do so as early as next week.

But for those gathered in Durham last Monday and other critics, two important details remain to be seen: whether and how quickly “a percentage” of biogas will become “100 percent.”

“Will they put their money where their mouth is?” asked Jim Warren, director of NC WARN, the Durham-based nonprofit that’s been one of the plant’s most forceful opponents. “Will they say, ‘we’re not going to burn shale gas?’”

‘I think we can get there’

Tatjana Vujic, another member of the Duke subcommittee, who’s spent more than a decade researching biogas in North Carolina, says a 100 percent biogas plant is within reach.

“I think we can get there. That’s what the university’s intent is,” said Vujic, who in January began working in the Office of the Executive Vice President specifically to bring biogas to campus. “That’s my job, is to get us there.”

The job is part of a decades-long quest in North Carolina to transform hog waste from a liability to an asset.

Today, roughly 10 billion gallons of waste – primarily from the state’s 9.5 million hogs – is stored at massive, factory-scale farms in open-air pits, which create pollution along with a foul stench that poses a nuisance to neighbors.

Covering the pits, capturing methane as the waste decomposes, then using the biogas for energy can produce a triple environmental benefit: less air and water pollution, less emissions of methane (a greenhouse gas many times more potent than carbon), and avoided use of fossil fuels.

Recognizing these advantages, Duke’s Climate Action Plan calls for switching its on-campus steam plants to biogas. In partnership with Duke Energy and Google, Inc., the university has also piloted a project in Yadkinville, where Loyd Ray Farms captures methane from nearly 9,000 hogs and combusts it onsite.

In 2013, a Nicholas Institute study found that removing impurities from methane and injecting the molecules directly into existing natural gas pipeline could make swine biogas more cost-effective.

This method, called “directed biogas,” is how the university could funnel swine gas from eastern North Carolina to its campus without building a new pipeline, or using tanker trucks that create carbon pollution of their own.

It’s also the method by which two new projects in Duplin County, in the heart of the state’s hog farming industry, will soon begin delivering renewable fuel to Duke Energy power plants and other customers.

“It’s as if we made a deposit in Duplin County, and we’re making a withdrawal in Durham,” said Vujic, who co-authored the 2013 report.

Still, challenges remain. New infrastructure, such as small pipelines to transport the methane from farms to existing gas lines, would be required. Some advocates worry the technology could perpetuate large-scale factory-style farming at the expense of local communities and their water supplies. The cost is still up to three times that of natural gas, according to experts.

“It’s an option, but it does come at a price,” said Randy Wheeless, spokesman for Duke Energy, the utility unrelated to the university that could build, own and operate the plant.

‘If you keep waiting, it’s not going to appear’

Skeptics say obstacles like these make a substantial delivery of biogas to Duke’s campus in the near term highly unlikely.

“Hopes that a gas-fired CHP plant built on campus might someday be converted to burn biogas from swine waste remain highly speculative due to technical, economic and social justice challenges that are many years from being resolved after more than a decade of effort,” NC WARN wrote in a fall report.

Warren reiterated that view at last week’s meeting, demanding of Profeta, “why not put this thing off for a few years, and get it right?”

But Profeta insists the university can help solve biogas’s economic challenges by acting sooner rather than later.

“We have an opportunity to become a demander of biogas and not the fracked gas we’ve been hearing about all night,” he said. “Is the market developed? No. Is there going to be a market unless somebody says, ‘I demand it at a premium’? No. If you keep on waiting for it to appear, it’s not going to appear.”

Angie Maier of the North Carolina Pork Council said Duke could play an important role in market development by advancing technology and “finding new ways of doing business.”

“This is a big undertaking, there’s no question,” said Maier, whose organization held a day-long workshop on swine-waste-to-energy in December. “But there’s a lot of people talking about this — a lot more than there was even six months ago. There’s a very different attitude right now, and a commitment to figure it out.”

To help illustrate how big a role the university could play, Vujic said the amount of biogas it could buy was close to the levels required under the state’s renewable energy law.

“When you’re thinking about it that way, it’s a very big demand signal,” she said. But, she stressed, “what we’re doing at the university, Duke Energy can’t put toward its quota. It’s an opportunity to expand the demand signal [even more].”

Peter Ledford of the North Carolina Sustainable Energy Association agreed that a biogas-powered plant at Duke would make it “one of few large consumers. They would be influential in getting things off the ground.”

Ledford, whose organization hasn’t taken a position on the proposed plant, said swine gas combined with high-efficiency CHP technology could be an elegant resolution to the controversy.

“It may well be that CHP with directed biogas is the most practical, viable environmental option out there,” he said.

Like most, Ledford knows no details of the subcommittee’s proposal. But critics say they will matter a great deal.

In addition to pushing for 100 percent biogas, some subcommittee members are pushing the university to identify a biogas supplier and commit to a significant purchase before moving forward with the plant.

“University administrators have said that Duke wants biogas, not fracked gas,” said Claire Wang, head of Duke’s Climate Coalition and an early opponent of the plant. “But the university has to do its homework. If it says this plant is revolutionary, it has to have something to back that up.”

Based in Raleigh, North Carolina, Elizabeth has covered the state’s clean energy transition for the Energy News Network since 2016. She has also produced features for Environmental Health News and SEJournal, the news magazine of the Society of Environmental Journalists. A former communications director for the nonprofit Environment America, Elizabeth brings over two decades of environmental and energy policy experience to her reporting.