(AP) — Electric utilities in North Carolina have asked state regulators to delay a law that requires them to generate energy from pig or chicken waste.

The News & Observer of Raleigh reported Tuesday that Progress Energy, Duke Energy and other providers are asking the North Carolina Utilities Commission for a one-year delay. The 2007 law requires utilities to begin getting some energy from pig and chicken manure by 2012.

The utilities also want the commission to cut the minimum energy requirement from poultry waste starting in 2014 by a third.

Disposing of the waste created by the pork and poultry industries is a major environmental challenge in North Carolina. Legislative leaders thought that it was a good idea to turn some of that waste into electricity.

Progress Energy spokesman Mike Hughes said lawmakers believed when they approved the law that a waste-to-energy market would develop, but that hasn't happened in North Carolina.

Progress hasn't received "a single viable swine proposal," he said. The only poultry project costs so much that it would reduce how much the company can invest in other green energies such as solar, he said.

The law limits how much the utilities can spend on renewable energy projects because those costs can be passed on to ratepayers.

The Utilities Commission has some authority to revise the law's provisions. Robert Gruber, head of the commission's Public Staff, which acts on behalf of consumers, said he agrees that the utilities need more time to abide by the law.

"The suppliers have raised some legitimate concerns about the potential cost," he said.

Source: Associated Press