Under the new rule, future power plants will be required to limit carbon emissions to a maximum of 1,000 pounds of carbon dioxide per megawatt of electricity produced. The ground-breaking rule represents the first time that carbon standards have been imposed on industry, and could end the construction of conventional coal-fired facilities in the United States.

“We’re putting in place a standard that relies on the use of clean, American made technology to tackle a challenge that we can’t leave to our kids and grandkids,” EPA Administrator Lisa Jackson said in a press release. “Right now there are no limits to the amount of carbon pollution that future power plants will be able to put into our skies – and the health and economic threats of a changing climate continue to grow.”

Coal-fired power plants today emit an average of 1,768 pounds of CO2 per megawatt. In order to reduce emissions to the new standard, coal-fired plants would have to install expensive carbon-capture and storage (CCS) pollution reducing technology, which the industry claims is cost-prohibitive.

The new EPA regulations favor the development of natural gas power generation plants, which emit an average of 800 to 850 pounds of CO2 per megawatt, already well below the proposed 1,000 pound limit.

While the future of coal is under a cloud darkened by excessive carbon emissions, coal today is still the most cost-efficient form of energy, and accounts for 40% of U.S. electric power generation.

While the future of coal is under a cloud darkened by excessive carbon emissions, coal today is still the most cost-efficient form of energy, and accounts for 40% of U.S. electric power generation. The new EPA standards reflect a trend away from carbon intensive energy generation, rather than a sudden reversal. Coal will continue to be tapped as an energy source, but the new ruling is seen as a boost for the development of cleaner energy technologies in the years ahead. Fossil fuels, nuclear, hydro and, increasingly, renewable energy sources will each contribute to future energy needs.

The proposed rule would apply only to new fossil‐fuel‐fired electric utility generating units (EGUs). Fossil‐fuel‐fired EGUs include fossil‐fuel‐fired boilers, integrated gasification combined cycle units and stationary combine cycle turbine units that generate electricity for sale and are larger than 25 megawatts. The rule provides an exception for coal plants that are already permitted and beginning construction within a year. There are about 20 coal plants now pursuing permits; two of them are federally subsidized and would meet the new standard with advanced pollution controls.

To help ensure continued use of a diverse range of domestically produced fuel sources, the proposed standard provides flexibilities for new power plants to phase in technologies which reduce carbon pollution. New power plants that use CCS would have the option to use a 30‐year average of CO2 emissions to meet the proposed standard, rather than meeting the annual standard each year. Super-efficient coal plants would be granted an exemption for the first decade of operation before requiring them to reduce their carbon emissions by more than 50 percent.

Although the proposed regulation targets future energy plants, there are retroactive repercussions. Utility companies have announced that they plan to shut down more than 300 boilers, representing more than 42 gigawatts of electricity generation — nearly 13 percent of the nation’s coal-fired electricity — rather than upgrade them with pollution-control technology.

Fossil-fuel industry proponents are expected to react strongly to the proposed EPA rule, and political supporters will raise the issue throughout this year’s election cycle

Fossil-fuel industry proponents are expected to react strongly to the proposed EPA rule, and political supporters will raise the issue throughout this year’s election cycle. But the writing may be on the wall for conventional coal, in the face of advances in clean energy sources as well as the new regulations.

“Gas is contributing to the closure of these plants,” Dominion Resources chief executive Thomas F. Farrell II said in a recent interview. Farrell, who also chairs the Edison Electric Institute, the utility trade association, added: “It’s not all EPA. It’s a combination of low gas prices and EPA working at the same time.”

The EPA rule will be subject to public comment before being finalized, but its backers are confident that the White House will sign it into law before Obama’s term ends. And while some environmentalists are disappointed the measure does not address the hundreds of existing coal-fired power plants, the proposed regulation will encourage future plants to embrace advanced CCS strategies or see coal-fired power plants go the way of the dinosaur.