The mandate, enacted by the N.C. General Assembly in the state’s renewable energy portfolio in 2007, was delayed in 2012 and 2013 by the state Utilities Commission after power producers said the technology was not ready and costs were too high, reports NewsObserver.

North Carolina is the only state in the nation that requires electric companies to use poultry and swine waste as a fuel for power generation. The leading renewable energy resource is solar power, ranking the state fourth nationally for total solar energy capacity.

On 28 August, Duke Energy Carolinas, Duke Energy Progress along with other electric utilities, rural electric cooperatives and municipal power agencies asked the Utilities Commission delay the swine waste requirement for one more year.

The filing does not provide details on how close the companies are to meeting the goal, as their fuel and power contracts are confidential, but it is clear they are approaching the target. One of the filers, Dominion N.C. Power, said in a separate filing it could meet the swine waste mandate this year.

North Carolina requires that at least 170,000 megawatt hours of electricity come from poultry waste this year. The state also requires that 0.07 per cent of power sold to retail customers come from swine waste. Those requirements increase in subsequent years.

Poultry waste, which is dry and easy to transport, is typically trucked to generators and incinerated or mixed with other fuel sources, like wood chips. Swine waste, which is soggy, is typically tapped for methane gas at the farm.

Poultry waste has other advantages. Burning it for heat to offset electricity use qualifies under the state’s renewable standard.

And a project called ReVenture Park in Charlotte qualifies for burning chicken droppings even though it only burns wood, under an exemption granted by the state legislature in 2010. The law also allows ReVenture to get credit for 3 megawatts of renewables for every 1 megawatt of power produced.