Q772. What are the differences in the universe of electricity generating units (EGUs) that report Greenhouse Gas (GHG) emissions to EPA's Clean Air Markets Division (CAMD) under Part 75 and to EPA's Greenhouse Gas Reporting Program under Part 98?

A772. The universe of EGUs that report GHG emissions under Part 98 is broader than the universe that report under Part 75. Below are some key differences:

• The ARP and RGGI apply only to EGUs that serve a generator exceeding 25 megawatts and there are also other unit-specific exemptions from the ARP and RGGI. There are no unit-specific exemptions under Part 98.
• All EGUs subject to the ARP and/or RGGI are located in the continental United States whereas Part 98 applies to EGUs located in the continental United States plus Hawaii, Alaska, and off-shore U.S. territories and possessions.
• EGUs that report annual CO2 mass emissions on a year-round basis under Part 75, must also report their annual GHG emissions (CO2, CH4 and N2O) under Subpart D of Part 98. All other EGUs 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.