Near the middle of a dusty construction site here stands a patch of land, about the size of two football fields, notable because it is empty.
Duke Energy has high hopes for this two-acre plot: If all goes right, and there is a happy convergence of technology, money and federal energy policy, the construction project could become the first environment-friendly coal-fired power plant in the nation.
The company is studying a method for capturing the carbon dioxide produced by using coal and storing the gas underground, preventing it from entering the atmosphere. Machines to separate carbon dioxide from other elements in the coal may someday stand on the empty land.
For years, scientists have been experimenting with ways to “clean” coal, a carbon-heavy fuel that countries around the world increasingly rely on. But the technology for carbon capture and storage has been tried only on a small scale. Governments have not required companies to do what Duke is proposing here, in part because costs were so uncertain.
The allocation of $3.4 billion in the federal stimulus bill for carbon capture and sequestration, as carbon storage is often called, however, has allowed Duke Energy and other companies to consider mounting full-scale projects.
The federal money is the latest sign of a growing interest worldwide in clean coal technologies, which backers believe could prove one of the most significant ways to tackle global warming. The projects are being watched closely by environmentalists, engineers and energy officials.
The Duke effort, said John Thompson, a coal expert at an environmental group, the Clean Air Task Force, “may be the first commercial carbon sequestration site in the United States.”
If Duke is successful, the plant could be capturing about 18 percent of its carbon dioxide emissions within four or five years, and an additional 40 percent a few years after that. Carbon dioxide is the main heat-trapping gas linked to global warming.
Duke already received some money under the Energy Policy Act of 2005 to build a $2.35 billion coal-burning power plant, the largest new construction project in Indiana. The site here is already crawling with workmen and heavy machinery.
The new plant will differ from conventional coal plants in significant ways, cooking the coal into a fuel gas rather than burning it as a powder, and then thoroughly cleaning the gas and burning it in a jet engine, similar to that used to burn natural gas. Emissions of conventional pollutants, like sulfur, soot and smog-forming nitrogen, will be extremely low.
Two other such “gasification” plants already operate, in Florida and Indiana. Duke’s first addition would be to use a machine to strip the carbon dioxide out of the fuel gas.