EPA's GHG Emissions from Electric Utility Generating Units

May 10, 2014

Sofie E. Miller

Download this Public Interest Comment (PDF)


The proposed rule would establish new standards of performance for carbon dioxide (CO2) emissions from coal- and natural gas-fired power plants, or electric generating units (EGUs). Pursuant to Section 111 of the Clean Air Act, EPA must establish federal standards of performance for new sources which, in the judgment of the Administrator, “cause, or contribute significantly to, air pollution which may reasonably be anticipated to endanger public health or welfare.” The standards should “reflect the degree of emission limitation achievable through the application of the best system of emission reduction which (taking into account the cost of achieving such reduction and any nonair quality health and environmental impact and energy requirements) the Administrator determines has been adequately demonstrated.” EPA refers to this as the best system of emission reduction (BSER).

EPA is proposing different emissions performance standards for coal-fired EGUs and natural gas-fired EGUs. For coal-fired EGUs, EPA is proposing CO2 emission limits of 1,100 lb/MWh, a standard that will not be achievable without partial use of carbon capture and storage (CCS). For natural gas-fired EGUs, EPA is proposing emission limits of 1,000 lb CO2/MWh for larger units, and 1,100 lb CO2/MWh for smaller units. There is no CCS requirement proposed for natural gasfired EGUs; instead, EPA has determined that already-existing efficient natural gas combined cycle (NGCC) technology is the BSER for natural gas EGUs.

As a part of its ongoing Retrospective Review Comment Project, the Regulatory Studies Center examines significant proposed regulations to assess whether agencies propose retrospective review as a part of their regulations, and submits comments to provide suggestions on how best to incorporate plans for retrospective review into their proposals. This comment will not address questions about the legal or policy merits of EPA’s decision to set standards for CO2 under Section 111 for coal and gas-fired EGUs, other than to examine the Agency’s use of retrospective review. To facilitate meaningful retrospective review after the promulgation of a final rule, multiple government guidelines instruct agencies to incorporate retrospective review plans into their proposals during the rulemaking process.