Q821. How did EPA determine a facility’s emissions by fuel type?
A821. EPA has published estimated combustion emissions data, by fuel type, for GHGRP facilities that report combustion emissions under Subparts AA (Pulp and Paper Production), C (General Stationary Fuel Combustion) and D (Electricity Generation)
The fuel types included are coal, natural gas, petroleum products, and other fuels. CO2 emissions from biogenic fuels are not included, however CH4 and N2O emissions from biogenic and partially biogenic fuels (e.g. tires, municipal solid waste) are included in the “other fuels” category. Sector-level emissions values displayed may differ from those in other publicly available datasets because some emissions from fuel combustion are reported under other subparts of the GHGRP (e.g. Subpart W, Petroleum and Natural Gas Systems) and because the GHGRP generally covers facilities that emit over 25,000 metric tons of carbon dioxide equivalent (mt CO2e) per year.
Many facilities report emissions by fuel type directly to EPA. In cases where CO2 emissions were reported at the unit level (i.e. CEMS-monitored sources), fuel level CO2 emissions estimates were calculated by EPA based on other data directly reported by facilities, as well as default emission factors.
Note that due to data quality issues with reported data, as well the limited information available to back calculate CO2 emissions for certain units, the sum of CO2e emissions reported across all fuels for a facility may differ from the total reported non-biogenic CO2e emissions. EPA will continue to refine the displayed estimates of emissions by fuel type to address these considerations.