Background Coal-Fired Plants
Coal is America’s most abundant energy resource. Approximately 30 percent of the world’s recoverable coal reserves are in this country. They contain more than 240 billion tons of recoverable coal—enough to last several hundred years at the current rate of use.
Most of the electricity generated in the United States comes from coal-burning power plants.
Coal also plays an important role in the energy security of this country. It would take an average of 102,000 barrels of oil a day to make the electricity that can be generated by Duke Energy’s coal-burning plants in the Carolinas.
Generating units at Duke Energy’s eight coal-fired power plants in the Carolinas can produce more than 7 million kilowatts of electricity at any one time—that’s enough electricity to light 70 million 100-watt lights. The units range in size from 40,000 kilowatts to more than 1.1 million kilowatts. Each year, they burn more than 10 million tons of coal.
Burning coal releases a number of combustion byproducts. Two of these products are coal fly ash and sulfur dioxide.
At coal-fired plants, a number of steps are taken to limit the amount of these substances released into the atmosphere. For example, our scientists sample a quantity of coal from every train carload the fossil plants receive.
The coal is analyzed to determine the amount of ash that will be left after it is burned. Duke Energy wants only coal with a low ash content so that less ash is available to go into the environment. Approximately 99.9 percent of the ash from burning coal is trapped within the power plant.
The coal is also analyzed for its sulfur content. The coal burned at Duke Energy’s fossil plants in the Carolinas has an average of less than one percent sulfur. Our lab ensures that the coal the company buys meets this low-sulfur standard.
When the coal is burned, some of this sulfur goes up the exhaust stacks and into the atmosphere as sulfur dioxide emissions. By using only high-quality, low-sulfur coal, smaller amounts of sulfur dioxide leave the stacks—ensuring minimal impact on air quality.
The efficiency of our coal-burning plants also helps to protect the environment. Because our plants burn less coal, lower amounts of sulfur dioxide are emitted.
Duke Energy’s commitment to the environment doesn’t end with air quality, and it’s not limited to only fossil plants. In 1923, Duke Power became one of the first utility companies in the country to launch an environmental program, hiring a renowned public health expert to help battle mosquitoes on its lakes. Now, more than 200 environmental scientists, technicians and engineers perform a full-time job monitoring and safeguarding the air, water and other natural resources surrounding the company’s generating plants in the Carolinas. They also conduct environmental impact studies for future facilities.
Through studies conducted in cooperation with university and wildlife experts, Duke Energy monitors the fish and other organisms in our lakes and uses this information when designing and operating power generating facilities. Under state supervision, Duke Energy also works to improve the habitat for game birds and game animals on transmission rights of way.
