Estimated fuel legs: parameters and sources

This page lists every ratio the estimated fuel legs multiply by, with where it came from. A leg is U = C x r, where C is the publisher's combustion value and r is a ratio from one of the tables below. The value-key columns give each donor value's value_key, the identifier the open-data files and the API carry for a factor value (on these physical values it equals the source_key, see identifiers), and each ratio is the first value divided by the second. The supply-chain model rows are held in the reference table fuel_chain_ratio, and every leg's source_record names the values or the row it used.

UK Government ratios (W3)#

The ratio for every fuel no earlier rung covers, from the UK Government GHG Conversion Factors for Company Reporting 2026, fuels: kg CO2e per kWh of net calorific value, AR5 on both legs, 2026, read from the flat-format file retrieved on 2026-09-18. The fuel codes are those of the fuel map; a code listed under a donor takes that donor's ratio.

city_gas_jp takes the LNG ratio because Japan's city gas is almost all imported LNG. The worked examples round these ratios to six places from the same two values: diesel 0.234686, the diesel blend 0.237083, LNG 0.353039.

co2emissiefactoren.nl ratios (W0)#

The ratio for the Netherlands, same year only, from co2emissiefactoren.nl's list: kg CO2e per the list's unit, well-to-tank (wtt) over tank-to-wheel (ttw), read from the yearly files retrieved on 2026-09-25. The list prints both legs from 2020 to 2026 (Jet A1 from 2021); the rows below are the years of RVO's bases.

The list prints natural gas per normal cubic metre (0.355 over 1.779 kg CO2e); it is served per litre, a thousandth of that. The ratio carries no unit, so it scales RVO's per-kilowatt-hour value. Marine diesel oil stands in for marine gas oil, and heavy fuel oil serves both fuel oil and marine fuel oil.

Supply-chain models (W1 and W2)#

One row per region, fuel and year of fuel_chain_ratio, each retrieved 2026-09-24. The upstream and combustion values share the unit given, and r is the first over the second.

• US gas. NETL's upstream emissions of gas delivered through the distribution network, over EPA's combustion factor for the same megajoule: 53.06 kg CO2 per mmBtu (Table C-1) plus CH4 and N2O (Table C-2) at AR6 (CH4 29.8, N2O 273).
• US coal. NETL's 2016 upstream emissions per kg of coal delivered to a power plant (model workbook, sheet "Pivot - Basin-Coal"), over EPA's combustion emissions of the same kg: Table C-1 bituminous 93.28, subbituminous 97.17, lignite 97.72 and mixed (electric power sector) 95.52 kg CO2 per mmBtu, plus the Table C-2 CH4 and N2O at AR6, at NETL's heating values (Exhibit 3-2) taken as gross. NETL prints results per basin: the average per rank is open-climate.ai's production weighting, and so is the 9,681 Btu per lb of the mixed coal. The mixed coal's upstream value is NETL's own US average row.
• New Zealand gas. Upstream: gas production and gathering (CRT 1.B.2.b.ii), Kapuni CO2 venting (1.B.2.c.i.2), the gas share of combined venting, flaring and exploration (1.B.2.c.i.3, 1.B.2.c.ii.3, 1.B.2.a.i), split by the gas and oil shares of indigenous production in MBIE's energy balance, gas used by the energy industries (1.A.1.c) and pipeline compressor gas (1.A.3.e.i). Combustion: gas burned in the economy (1.A), less the compressor gas, scaled up by the feedstock gas of methanol and urea. Network leaks (1.B.2.b.iv and v) are left out.
• EU gas. JEC's EU-mix piped gas summed over production, long-distance pipeline and high-pressure distribution, CNG compression left out. EU hard coal. JEC prints no per-MJ figure for process KO1, so it is back-calculated from pathway KOEL1's coal provision step over its coal input; pathways KOEL2, KOEL2C and KOCH agree to 0.001.

Calibration errors served#

The value's uncertainty_pct per rung and fuel family: the worst error of the rule's ratio against the ratio of a publisher who prints both legs, measured on 2026-09-25. "none" means nothing independent was measured and no uncertainty is served. The family coal holds petroleum coke, and liquids holds LPG, propane, butane and other petroleum gas.

The comparators, medians and worst rows are on the method page. No tier moves: every rung is served at its cap.

Sources#

• National Energy Technology Laboratory (NETL) (2025), Life Cycle Analysis of Natural Gas Extraction and Power Generation: U.S. 2020 Emissions Profile, Rev1 (DOE/NETL-2025/4933), Appendix E: https://edx.netl.doe.gov/dataset/2020-natural-gas-lca-appendices-rev1 (doi:10.18141/2568689). CC0 1.0, as tagged on NETL's data exchange. Changed: the upstream emissions were divided by EPA's combustion factor for the same megajoule.
• NETL (2023), Cradle-to-Gate Life Cycle Analysis Baseline for United States Coal Mining and Delivery (DOE/NETL-2024/4846), model workbook NETLCoalBaselineModel.xlsm: https://edx.netl.doe.gov/dataset/lca-baseline-for-us-coal-mining-and-delivery-data-products (doi:10.18141/2560300). CC0 1.0. Changed: basin results were averaged per rank by production, and each divided by EPA's combustion emissions of the same kg.
• U.S. Environmental Protection Agency, 40 CFR Part 98, subpart C, Tables C-1 and C-2: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-C/part-98/subpart-C. US Government work, public domain. Changed: CO2, CH4 and N2O summed to CO2e at AR6, and coal factors per mmBtu converted to per kg at NETL's heating values.
• JEC Well-to-Tank report v5 (Prussi, Yugo, De Prada, Padella, Edwards, Lonza; JRC119036, EUR 30269 EN, 2020; doi:10.2760/959137 and doi:10.2760/06704) and its pathway workbooks: https://publications.jrc.ec.europa.eu/repository/handle/JRC119036. © European Union 2020, CC BY 4.0. Changed: the gas pathway's steps were summed, and the hard coal figure back-calculated from a coal-to-electricity pathway.
• Ministry for the Environment (New Zealand) (2026), New Zealand's Greenhouse Gas Inventory 1990-2024, Common Reporting Tables (NZL-CRT-2026-V0.10) and National Inventory Document: https://environment.govt.nz/publications/new-zealands-greenhouse-gas-inventory-19902024/. CC BY 4.0. Changed: inventory categories were summed into an upstream and a combustion total, as listed above; no published figure was otherwise altered.
• Ministry of Business, Innovation and Employment (New Zealand), energy balance tables, calendar years 2022 to 2024: https://www.mbie.govt.nz/assets/Data-Files/Energy/nz-energy-quarterly-and-energy-in-nz/energy-balance-tables.xlsx. CC BY 4.0. Changed: the natural gas and oil shares of indigenous production were used to split the inventory's combined oil and gas rows.
• Department for Energy Security and Net Zero, UK Government GHG Conversion Factors for Company Reporting 2026: https://www.gov.uk/government/publications/greenhouse-gas-reporting-conversion-factors-2026. Contains public sector information licensed under the Open Government Licence v3.0. Changed: a ratio was computed from two printed values.
• co2emissiefactoren.nl, Lijst emissiefactoren: https://www.co2emissiefactoren.nl/lijst-emissiefactoren/. The site's terms of use. Changed: a ratio was computed from two printed values.
• GHG Protocol, Corporate Value Chain (Scope 3) Standard: https://ghgprotocol.org/sites/default/files/standards/Corporate-Value-Chain-Accounting-Reporing-Standard_041613_2.pdf. Technical Guidance for Calculating Scope 3 Emissions: https://ghgprotocol.org/sites/default/files/standards/Scope3_Calculation_Guidance_0.pdf.

Related#

• Estimated fuel legs: the supply chain before the burn
• Estimated electricity legs: parameters and sources
• Licences and redistribution of emission factors
• Units and unit conversions in emission factors