This afternoon, EPA announced proposed revisions to performance standards governing CO2 emissions from new, reconstructed and modified coal-fired electric generating units. The proposal would drop carbon capture and storage (CCS) as the best system of emission reduction (BSER) for new units in favor of efficient supercritical steam design for large units and subcritical design for smaller units, both in combination with best operating practices. EPA proposes to increase the corresponding performance standards consistent with the change in the BSER. Given the change in new source standards, EPA is also proposing conforming revisions to the standards for modified and reconstructed units and will add a proposed new standard for new and reconstructed units that burn coal refuse.

Overview of Proposed Changes

Affected EGUs 

Current Performance Standard Proposed New Performance Standard
New Coal-Fired Units

 

 

1,400 lb CO2/MWh gross

 

 

 

1,900 lb CO2/MWh gross for large units1 2,000 lb CO2/MWh gross for smaller units2

 

Reconstructed Coal-Fired Units

 

1,800 lb CO2/MWh gross for large units

2,000 lb CO2/MWh gross for smaller units

 

 

1,900 lb CO2/MWh gross for large units

No change for smaller units

 

New & Reconstructed Coal-Refuse-Fired Units

 

 

No separate standard

 

2,200 lb CO2/MWh-gross, regardless of the size of the unit
Modified Coal-Fired Units  

Unit-specific standards based on the unit’s best historical annual CO2 emission rate but no lower than 1,800 lb CO2/MWh gross for large units and 2,000 for smaller units

 

Same unit-specific approach but conforming the lower limit to the new source standards: 1,900 for large units, 2,000 for smaller units, and 2,200 for coal-refuse-fired units

1 Large units are defined as those having a base load rating of greater than 2000 MMBtu/hour.

2 Smaller units are defined as those having a base load rating of 2000 MMBtu/hour or less.

In addition to these changes, EPA is soliciting comment on the proper interpretation of the regulatory language providing the predicate for the regulations – the cause or contribute determination. Under Section 111 of the Act, before EPA can regulate, it must find that emissions from the source category “cause or contribute significantly to air pollution which may reasonably be anticipated to endanger public health or welfare.” EPA requests input on “the proper interpretation of this phrase, the agency’s historic approach to this requirement, and whether this requirement should apply differently in the context of greenhouse gases than for traditional pollutants.”

While EPA is not proposing revisions to the CO2 performance standards for natural gas fired units (simple cycle combustion turbines and combined cycle units), it does request comments on the current standard for new simple cycle aero-derivative turbines, including those used as back-up generation for wind and solar generation. Based on the feedback, EPA notes it might undertake separate action in the future on those standards.

This proposal responds to the Trump Administration’s Executive Order on Promoting Energy Independence and Economic Growth, which directed EPA and other agencies, to review existing regulations and revise or rescind “those that unduly burden the development of domestic energy resources beyond the degree necessary to protect the public interest or otherwise comply with the law.”

Comments on the proposed revisions will be due 60 days from the date of publication in the Federal Register. EPA’s proposal and supporting documentation are available here on EPA’s website.