"Most natural gas plants typically produce only one emission -- nitrogen oxide -- that is in excess of the proposed new EPA thresholds, but many coal plants may exceed all of the thresholds, making it more expensive for them to come into compliance," Pratson said. "This has spurred legal and political debates over whether the pending regulations unfairly disadvantage the U.S. coal industry."
The study takes no sides in the debate, he stressed. "We neither argue for nor against continued use of coal power. Our goal is to present an objective analysis of the economic sensitivity of both types of plants to fuel price fluctuations and the potential cost of emission-control upgrades."
Monthly emissions from the U.S. electricity sector have fallen to 1990s levels in recent years, helping to reduce total U.S. carbon dioxide emissions to their lowest levels since 1992. This CO2 decline is largely due to greater use of natural gas power plants in place of coal plants, a shift made possible by lower natural gas prices from the recent surge in domestic shale gas production.
Whether or not the shift to natural gas picks up speed and continues will depend on more than just whether the proposed EPA standards are enacted, Pratson noted. A transition to natural gas for electricity generation will require the construction of a much larger network of pipelines and other infrastructure to transport and store the gas, assuring power plants of a reliable supply.
The net effect of the shift to natural gas on global carbon dioxide emissions remains uncertain, Pratson said, since coal that is not consumed in the United States is already finding its way to other countries in Europe and Asia.
|Contact: Timothy Lucas|