9 investigates: Duke Energy looks to recycle millions of tons of coal ash

CHARLOTTE, N.C. — Duke Energy is racing to meet a state mandate to recycle millions of tons of coal ash.

For years, Channel 9 has covered the push to get the company to clean up coal ash, and Duke Energy’s attempts to raise customer rates to pay for it.

[LINK: Nu-Rock Technologies]

Now, there’s new technology that some environmentalists say could solve the problem.

Bill McMahan, CEO of Nu-Rock Technologies, is confident he has the solution.

“Once this is in the market, people building houses and condos and all the rest would much rather be building with this,” McMahon said.


Nu-Rock takes coal ash, the residue left after burning coal, and recycles it into bricks and pavers, and it does so using chemicals alone, no heat.

“Three to five percent of the energy used to make cement is what we use here,” McMahon said.

North Carolina alone has more than 100 million tons of coal ash.

Nu-Rock gets it from plants and landfills, then creates bricks that McMahan said are stronger and lighter than typical concrete.

“We can solve most companies' ash problem without too much of a problem and making some money doing it,” McMahon said.

McMahon said he is discussing the possibility of working with eight utilities across the U.S. to recycle their coal ash, but he won’t reveal which ones.

Duke Energy spokesperson Erin Culbert told Channel 9 the two have been in talks since 2015.

“NU-Rock is one of the companies we are having good conversations about,” Culbert said.

Channel 9 anchor Brittney Johnson asked Culbert why the process hasn’t moved forward.

“Many of these projects take time,” Culbert said.

Duke Energy is recycling only about 40 percent of the coal ash it produces in North Carolina each year. The rest is stored permanently, either in ash basins, which they’re working to close, or in lined landfills.

Duke Energy officials said the big barrier to more recycling is the high carbon content of coal ash, which makes it hard to use in concrete.

Duke Energy doesn't have the facilities to recycle any more than it already does, but it is in the process of converting Buck Steam Station in Rowan County into a plant that can remove carbon from coal ash so more of it can be recycled safely.

Crews are in the early stages of preparing the area for a $180 million reprocessing plant.

Duke Energy said recycling is much cheaper than excavating and storing the coal ash permanently, and the money from selling recycled coal ash will come back to customers.

“It actually helps prevent really dramatic rate hikes in the future,” Culbert said.

McMahon said Nu-Rock could save companies like Duke Energy even more money because it can directly process the coal ash with high carbon content.

“It takes care of one of the biggest environmental problems we have in the United States,” McMahon said.

Duke Energy has more than 100 million tons of ash sitting in coal ash basins that it must close by 2029.

If it can't recycle the ash, it will have to store it and customers will have to pay for it.

McMahon said if the companies come to an agreement, Nu-Rock could have a plant built on site within six months, and that each plant will bring dozens or possibly hundreds of jobs to the area.