Impact Factors of Fuel Production and Use

Methods 5.0

Published

September 22, 2025

For FP v5, the fuel options have been reduced and tied to specific operations. We have also incorporated more reliable data and separated the impact factors by on-farm combustion and upstream manufacturing impacts for the procured fuel.

The FP v5 will not include biogenic CO2 from biofuels in the final estimate for the GHG Emissions metric, as permitted by the Greenhouse Gas Reporting Program (GHGRP).

How the fuels are linked to operations
Category Diesel1 Gasoline LPG Natural gas Biodiesel2 Diesel3
Irrigation pumping ✓ ✓ ✓ ✓
Crop drying ✓ ✓ ✓ ✓
Crop transportation ✓ ✓
Manure transportation ✓
Field operations ✓
Agricultural input transportation ✓

Details

Fuel emission factors encompass both combustion emissions and upstream emissions associated with fuel extraction, distribution, and refining. Combustion emissions are derived from the EPA Emission Factor Hub, which provides estimates of CO2, CH4, and N2O emissions per unit of fuel combusted (USEPA 2023). Since fuel-related emissions vary depending on whether the fuel is used in stationary combustion equipment (e.g. grain dryers) or mobile applications (e.g. tractors, off-road agricultural machinery and trucks, and on-road trucks), separate emission factors are applied for each category.

For stationary combustion, the EPA emission factors are provided per unit of higher heating value (HHV). However, most agricultural and transportation applications do not utilize the latent heat from fuel combustion, as vapor recondensing technologies are uncommon in these sectors, and therefore energy usage for agricultural and transportation operations are measured in lower heating value (LHV) energy units. To align the emission estimates with agricultural energy use practices, we convert HHV based emission factors into LHV-based factors using standard conversion factors for each fuel type (Tools 2024; USEPA 2023). For mobile combustion, fuel-specific emission factors are applied based on mode-specific data for off-road trucks and machinery, on-road trucks, and other agricultural vehicles. These values reflect variations in engine efficiencies, combustion conditions, and regulatory emission controls across different fuel applications (USEPA 2023).

In addition to combustion emissions, upstream emissions from fuel production are incorporated into the analysis to account for cradle-to-processing-gate emissions, including from fuel extraction, transport, refining, and processing. The GREET 2023 model is used to estimate GHG emissions per MJ (LHV) of fuel throughput, ensuring all stages of fuel production are properly captured (Wang et al. 2023). Furthermore, GREET provides estimated cumulative energy demand (CED) per unit of fuel throughput. For example, for every MJ of diesel combusted, the CED is 1.12 MJ, reflecting both direct combustion energy and the additional energy required for extraction, refining, and distribution. For renewable soy biodiesel fuels, CED and GWP capture impacts from soybean cultivation, crushing, and biodiesel processing (Wang et al. 2023).

Energy use

The energy use impact factors are explained below.

  • System Boundary: This enables the disaggregation of upstream and combustion factors. Combustion factors are attributed to On-Farm Mechanical or Post-harvest boundaries. The combustion factors for On-Farm Mechanical or Post-harvest are the same.
  • Source Category: It classifies the energy use to indicate whether it is associated with production of fuels (upstream), mobile machinery (field equipment, crop transportation, manure transportation), and stationary machinery (irrigation pumps and crop dryers).
  • Source: A given fuel.
  • MJ: Impact factor of megajoules per unit.
  • Unit (LHV): Expected unit to use the MJ impact factor.
Table 1: Energy use associated with fuel production and use.
System Boundary Source Category Source MJ Unit (LHV)
Upstream production of fuels Biodiesel (on-road heavy-duty truck) 74.34 gallon
Upstream production of fuels Diesel (ag equipment) 15.94 gallon
Upstream production of fuels Diesel (on-road medium-heavy duty truck) 15.94 gallon
Upstream production of fuels Gasoline 26.93 gallon
Upstream production of fuels LPG 12.70 gallon
Upstream production of fuels Natural gas 0.11 SCF
Upstream transportation of agricultural inputs Diesel (on-road medium-heavy duty truck) 160.88 gallon
Post-Harvest mobile machinery Diesel (on-road medium-heavy duty truck) 144.94 gallon
Post-Harvest mobile machinery Biodiesel (on-road heavy-duty truck) 126.13 gallon
Post-Harvest stationary machinery Diesel (ag equipment) 144.94 gallon
Post-Harvest stationary machinery Gasoline 118.29 gallon
Post-Harvest stationary machinery LPG 88.89 gallon
Post-Harvest stationary machinery Natural gas 1.08 SCF
On-Farm Mechanical mobile machinery Diesel (ag equipment) 144.94 gallon
On-Farm Mechanical mobile machinery Diesel (on-road medium-heavy duty truck) 144.94 gallon
On-Farm Mechanical mobile machinery Biodiesel (on-road heavy-duty truck) 126.13 gallon
On-Farm Mechanical stationary machinery Diesel (ag equipment) 144.94 gallon
On-Farm Mechanical stationary machinery Gasoline 118.29 gallon
On-Farm Mechanical stationary machinery LPG 88.89 gallon
On-Farm Mechanical stationary machinery Natural gas 1.08 SCF

GHG emissions

The GHG emissions impact factors are explained below.

  • System Boundary: This enables the disaggregation of upstream and combustion factors. Combustion factors are attributed to On-Farm Mechanical or Post-harvest boundaries. The combustion factors for On-Farm Mechanical or Post-harvest are the same.
  • Source Category: It classifies the GHG emissions to indicate whether it is associated with production of fuels (upstream), mobile machinery (field equipment, crop transportation, manure transportation), and stationary machinery (irrigation pumps and crop dryers).
  • Source: A given fuel.
  • CO2_fossil: Impact factor for fossil CO2 in kg of gas per unit.
  • CO2_biogenic: Impact factor for biogenic CO2 in kg of gas per unit. It is important to note that the Greenhouse Gas Reporting Program (GHGRP) allows for the non-inclusion of biogenic CO2 from inventories, except for those CO2 emissions from direct land use change and soil carbon stock changes.
  • CH4_fossil: Impact factor of fossil CH4 in kg of gas per unit.
  • CH4_biogenic: Impact factor of biogenic CH4 in kg of gas per unit.
  • N2O: Impact factor for N2O in kg of gas per unit.
  • Unit (LHV): Expected unit to use the impact factors for each GHG gas.
Table 2: GHG emissions associated with fuel production and use.
System Boundary Source Category Source CO2_fossil CO2_biogenic CH4_fossil CH4_biogenic N2O Unit (LHV)
Upstream production of fuels Biodiesel (on-road heavy-duty truck) 2.24 0.00 0.0037037 0.00e+00 0.0010976 gallon
Upstream production of fuels Diesel (ag equipment) 0.97 0.00 0.0023290 0.00e+00 0.0000195 gallon
Upstream production of fuels Diesel (on-road medium-heavy duty truck) 0.97 0.00 0.0023290 0.00e+00 0.0000195 gallon
Upstream production of fuels Gasoline 1.68 0.00 0.0046768 0.00e+00 0.0003232 gallon
Upstream production of fuels LPG 0.91 0.00 0.0025506 0.00e+00 0.0000152 gallon
Upstream production of fuels Natural gas 0.01 0.00 0.0001952 0.00e+00 0.0000013 SCF
Upstream transportation of agricultural inputs Diesel (on-road medium-heavy duty truck) 11.18 0.00 0.0032384 0.00e+00 0.0003245 gallon
Post-Harvest transportation of crop production Biodiesel (on-road heavy-duty truck) 0.00 9.48 0.0000000 9.95e-05 0.0000142 gallon
Post-Harvest transportation of crop production Diesel (on-road medium-heavy duty truck) 10.20 0.00 0.0009094 0.00e+00 0.0003050 gallon
Post-Harvest stationary machinery Diesel (ag equipment) 10.20 0.00 0.0012692 0.00e+00 0.0010693 gallon
Post-Harvest stationary machinery Gasoline 8.72 0.00 0.0003727 0.00e+00 0.0000745 gallon
Post-Harvest stationary machinery LPG 5.64 0.00 0.0002744 0.00e+00 0.0000549 gallon
Post-Harvest stationary machinery Natural gas 0.05 0.00 0.0000010 0.00e+00 0.0000001 SCF
On-Farm Mechanical mobile machinery Diesel (ag equipment) 10.20 0.00 0.0012692 0.00e+00 0.0010693 gallon
On-Farm Mechanical transportation of crop production Biodiesel (on-road heavy-duty truck) 0.00 9.48 0.0000000 9.95e-05 0.0000142 gallon
On-Farm Mechanical transportation of crop production Diesel (on-road medium-heavy duty truck) 10.20 0.00 0.0009094 0.00e+00 0.0003050 gallon
On-Farm Mechanical stationary machinery Diesel (ag equipment) 10.20 0.00 0.0012692 0.00e+00 0.0010693 gallon
On-Farm Mechanical stationary machinery Gasoline 8.72 0.00 0.0003727 0.00e+00 0.0000745 gallon
On-Farm Mechanical stationary machinery LPG 5.64 0.00 0.0002744 0.00e+00 0.0000549 gallon
On-Farm Mechanical stationary machinery Natural gas 0.05 0.00 0.0000010 0.00e+00 0.0000001 SCF
On-Farm Mechanical mobile machinery Diesel (on-road medium-heavy duty truck) 10.20 0.00 0.0009094 0.00e+00 0.0003050 gallon

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References

Tools, Hydrogen. 2024. “Hydrogen Analysis Resource Center (HYARC) Calculators.” https://h2tools.org/hyarc/calculator-tools/lower-and-higher-heating-values-fuels.
USEPA. 2023. “GHG Emission Factors Hub.” U.S. Environmental Protection Agency. https://www.epa.gov/climateleadership/ghg-emission-factors-hub.
Wang, Michael, Amgad Elgowainy, Uisung Lee, Kwang Hoon Baek, Sweta Balchandani, Pahola Thathiana Benavides, Andrew Burnham, et al. 2023. “Summary of Expansions and Updates in r&d GREET 2023.” Argonne National Laboratory (ANL), Argonne, IL (United States).