FAQ > GHG Data and Publication > Q772. What are the differences in the universe of electricity generating units (EGUs) that report Greenhouse Gas (GHG) emissions to EPA Part 75 Monitoring and to EPA’s Greenhouse Gas Reporting Program (GHGRP) under Part 98?
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Q772. What are the differences in the universe of electricity generating units (EGUs) that report Greenhouse Gas (GHG) emissions to EPA Part 75 Monitoring and to EPA’s Greenhouse Gas Reporting Program (GHGRP) under Part 98?


A772.  The universe of EGUs that report GHG emissions under Part 98 is broader than the universe that report CO2 under Part 75. The Part 75 reporting program is used to implement emission control programs from large fossil fuel-fired EGUs. EGUs that report under Part 75 must report greenhouse gas emissions to the GHGRP under Subpart D of Part 98. EGUs that do not report CO2 emissions under Part 75 must report greenhouse gas emissions under Subpart C of Part 98.

  • The universe of EGUs reporting CO2 emissions to CAMD under Part 75 comprises EGUs subject to the Acid Rain Program (ARP), Regional Greenhouse Gas Initiative (RGGI), and Carbon Pollution Standards for New, Modified and Reconstructed Power Plants (111(b)).

  • EGUs that report annual CO2 mass emissions on an hourly basis under Part 75, must also report their annual CO2, CH4, and N2O mass emissions under Subpart D of Part 98. All other EGUs and non-EGU stationary combustion units located at facilities that meet the applicability criteria of Part 98 (see §98.2(a)) must report their annual GHG emissions under Subpart C of Part 98.

  • The following examples highlight some cases where an EGU may not be subject to Part 75 but is subject to Subpart C of Part 98:

    • The ARP applies only to EGUs that serve a generator exceeding 25 megawatts (MW) nameplate capacity and RGGI applies only to EGUs that serve a generator greater than or equal to 25 MW nameplate capacity.  There are also other unit-specific exemptions from the ARP and RGGI. There are no unit-specific exemptions for EGUs under Part 98.  Units that meet the applicability criteria of Part 98 (see §98.2(a)) that serve a generator with a capacity less than 25MW are not subject to Part 75 but are subject to Part 98 and must be reported under Subpart C.
    • EGUs located outside of the contiguous United States are subject to Part 98 but not Part 75.  All EGUs subject to the ARP and/or RGGI are located in the contiguous United States. Part 98 applies to EGUs located in the contiguous United States plus Hawaii, Alaska, and U.S. territories and possessions.



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