Duke Energy Begins Processing Coal Ash For Recycling At 2 North Carolina Plants
Duke Energy has begun processing coal ash for recycling at two new plants in Salisbury and Goldsboro, and a third is expected to come online by year's end in Chatham County. The new plants are required by state law, as part of Duke's coal ash cleanups, but also could help the concrete industry.
Coal ash is what's left after coal is burned for electricity. It contains heavy metals linked to cancer and other ailments. Ash also has beneficial uses, including as an additive to strengthen concrete. But what comes out of Duke's coal-fired power plants is too high in carbon to meet the industry's needs without processing, so the region has imported ash from other countries.
Duke spokesman Bill Norton said these three plants now will reduce the concrete industry's need for imported ash.
"We'll be able to serve the market in Virginia, both Carolinas, Georgia and Tennessee. We've got a large region covered," Norton said outside the Salisbury plant Wednesday morning.
North Carolina's 2016 Coal Ash Management Act required Duke to build the plants at three retired coal-fired power plants where millions of tons of coal ash are stored - the Buck plant in Salisbury, H.F. Lee Plant in Goldsboro, in Wayne County, and at the Cape Fear plant in Moncure, in Chatham County.
All together, they will process 1.2 million tons of ash a year. That's more than all the ash Duke Energy now creates in a year in North Carolina, Norton said.
Norton said revenue from coal ash sales will help pay for the plants' hefty construction costs.
"Operating this facility and selling that processed ash is a less-expensive proposition for customers than excavating and landfilling the ash elsewhere," he said.
Buck Steam Station was retired in 2013, and Duke now operates a gas-fired electricity plant there. After almost nine decades of operation, the coal-fired plant left 6.6 million tons of coal ash in mounds and ponds nearby.
"We've been getting the (coal ash) basins ready for this day," Norton said. "We couldn't excavate them until this facility was online. But we've begun excavating the ash now for recycling. We expect it'll take about 2035 to excavate it all."
The $240 million Buck recycling plant began operating in September. It has three main sections:
- A warehouse at one end receives coal ash dug up from the three nearby coal-ash storage basins.
- A central complex heats coal ash to a high temperature to remove excess carbon.
- And a large white dome at the other end holds processed ash before shipping.
From there, sealed tanker trucks pick up the ash and transport it to concrete companies. Norton notes that once it's processed, the ash "actually never sees the light of day until it reaches the concrete manufacturer."
Duke Energy owns the ash recycling plants but contracts with a South Carolina company, The SEFA Group, to operate them.
Duke will be digging up and processing ash at the three North Carolina sites for the next 15 years, Norton said.
At the rest of Duke's 14 current and former coal-fired plants, Duke by law must dig up coal ash and move it to new lined landfills. That's supposed to prevent it from leaking into groundwater.
So why can't Duke build recycling plants elsewhere? Norton gives a complicated answer:
"If we had the market demand to recycle more ash, that would be a great problem to have," he said. "Right now, we think these three facilities have the market covered, but we'd always be open to recycling more."
Another problem, he said, is the large amount of coal ash at Duke's other plants and state-mandated deadlines to remove it.
At Marshall Steam Station on Lake Norman, Duke plans to move 16 million tons of coal ash into a new lined landfill. Norton said these recycling plants can only process about 400,000 tons a year.
"At the rate that this processes ash, we could not meet our deadlines. So landfilling that ash is more efficient," he said.