By Lauren Smith
On Tuesday, March 27, the U.S. Environmental Protection Agency (EPA) announced new performance standards limiting carbon dioxide emissions from power plants. The standard, which applies only to new power plants, limits CO2 emissions to 1,000 lbs per megawatt-hour (lb CO2/MWh).
The proposed rule is significant because it would be the first explicit limit on CO2 emissions in the United States. It effectively brings to an end new construction of conventional coal-fired power plants, which cannot meet the standard. Typically, new coal plants generate about 1,800 lb CO2/MWh (or between 1,600 to 1,900 lb CO2/MWh). This means any new coal plants will have to adopt new technologies to reduce emissions, namely carbon capture and storage (CCS). Natural gas plants, on the other hand, emit around 800-850 lb CO2/MWh well within the standard. In fact, the EPA based the emission limit on “the performance of widely used natural gas combined cycle (NGCC) technology” and predicts that NGCC will be the predominant choice in new fossil-fuel powered electricity generation. The rule does not apply to plants which have already been permitted.
The process of developing these standards was set in motion by the US Supreme Court’s 2007 decision in Massachusetts v. Environmental Protection Agency. The suit was brought by seven states, three cities and a number of organizations seeking to compel EPA to regulate greenhouse gas emissions. The Court found that in fact EPA has authority and responsibility to consider regulation of carbon dioxide and other greenhouse gases under the Clean Air Act (CAA). In 2009, EPA released an “endangerment finding” on greenhouse gases, a determination that the public health and climate change impacts of key greenhouse gases are sufficient to warrant regulation. The current standards are the first to come out of this lengthy process.
Note: Specifically, EPA is authorized by the Clean Air Act section 111 to develop standards for stationary sources, referred to as New Source Performance Standards.
Electricity generation is a major source of greenhouse gas emissions. In the report Emissions of Greenhouse Gases in the United States 2009 (published in 2011), the Energy Information Administration details the main sources of greenhouse gases in the U.S. In terms of energy-related carbon dioxide emissions (by fuel type), coal contributes 34.6% (natural gas contributes 22.4% and petroleum contributes the other 42.7% or so). Thinking of this in terms of scale, energy-related carbon dioxide emissions contribute over 80% of all U.S. greenhouse gas emissions (but this includes transportation and other sectors). The electric power sector is responsible for 39.8% of carbon dioxide emissions.
While coal producers and some utilities are up in arms about the new carbon pollution standard, it is not completely surprising that other technologies are being promoted over conventional coal plants. Coal plants have become increasingly less competitive due to factors such as low natural gas prices and the expansion of natural gas reservoirs through hydrofracking, higher coal prices driven by China’s demand, and lower electricity demand.
Lauren Smith is an intern at the Columbia Climate Center and a graduate student in the Climate and Society program at Columbia University.