Duke Energy is turning to home-grown pig poop to help it comply with state law.
The Charlotte-based utility on Thursday said one of its power plants in central North Carolina has begun burning natural gas created from N.C. manure.
Duke said it must generate 0.2 percent of its retail electricity sales from pig waste by 2021, under the Renewable Energy and Energy Efficiency Portfolio Standard law passed in 2007.
In the past, Duke has gone outside North Carolina to buy natural gas created from pig waste and burned it in North Carolina to generate electricity, Duke spokesman Randy Wheeless said. But the Smith Energy Complex in Richmond County marks Duke's first plant burning natural gas generated by pig farms in North Carolina, he said.
The plant began using that natural gas last week.
The project involves the capture of methane from hog waste at five farms in Duplin County. The methane is converted to pipeline-quality natural gas that is transported to the Smith plant, where it is used to produce electricity.
Meeting the 0.2 percent mandate has been a challenge, in part to difficulties that developers face in bringing such projects online, Wheeless said. Duke is hoping the Duplin project will help spur similar projects, he said.
Announced in 2016, the Duplin project is expected to produce about 11,000 megawatt-hours of electricity, enough to power about 1,000 homes, according to Duke.
Duke says it has been expanding its reliance on renewable energy sources for electricity generation.
In 2005, the company was not generating electricity from renewable sources, according to a report it released this month. By the end of last year, renewable sources made up 5 percent of its overall fuel types, a figure expected to increase to 10 percent by 2030, the report says.