Emission Factors Reference
The essential reference for converting activity data into CO₂ equivalents. Regional electricity factors, sector-specific data, recommended databases, and practical selection guidance.
What Are Emission Factors?
An emission factor is a coefficient that relates the quantity of a pollutant released to the atmosphere to a specific activity. In carbon accounting, emission factors convert activity data — such as kilowatt-hours of electricity, litres of fuel, or kilometres travelled — into kilograms or tonnes of CO₂ equivalent (CO₂e).
The formula is straightforward:
Emissions = Activity Data × Emission Factor
For example, if your office consumes 10,000 kWh of electricity in a year and the grid emission factor for your region is 0.4 kg CO₂e/kWh, your Scope 2 emissions would be:
10,000 kWh × 0.4 kg CO₂e/kWh = 4,000 kg CO₂e = 4 tonnes CO₂e
Selecting the right emission factor is one of the most consequential decisions in carbon accounting. The factor you choose directly determines your reported emissions total, your reduction targets, and your compliance status.
Regional Electricity Factors
Grid electricity emission factors vary significantly by country and region, reflecting the local energy mix. These factors are essential for Scope 2 calculations.
| Country / Region | kg CO₂e / kWh | Primary Energy Mix | Data Source |
|---|---|---|---|
| European Union (average) | 0.25 – 0.30 | Nuclear, renewables, natural gas | EEA / Eurostat |
| United Kingdom | 0.20 – 0.25 | Wind, natural gas, nuclear | DESNZ / BEIS |
| Germany | 0.35 – 0.45 | Coal, wind, natural gas | Bundesnetzagentur |
| France | 0.05 – 0.08 | Nuclear (dominant), hydro | RTE / Citepa |
| United States (average) | 0.35 – 0.45 | Natural gas, coal, nuclear | EPA eGRID |
| China (average) | 0.55 – 0.65 | Coal (dominant), hydro, wind | NDRC / IEA |
| India | 0.70 – 0.80 | Coal (dominant), solar, hydro | CEA / IEA |
| Australia | 0.50 – 0.65 | Coal, natural gas, renewables | NGA Factors / DCCEEW |
| Morocco | 0.60 – 0.70 | Coal, natural gas, renewables | ONEE / IEA |
| Brazil | 0.10 – 0.15 | Hydro (dominant), wind, biomass | MME / IEA |
Note: Factors are approximate ranges for location-based reporting. Use the most recent official data for your specific country and year. Market-based factors (renewable energy certificates) may differ significantly.
Sector-Specific Factors
Beyond electricity, each sector has characteristic emission sources and corresponding factors. Selecting sector-appropriate factors improves accuracy and comparability.
Transportation
| Fuel / Mode | kg CO₂e / unit |
|---|---|
| Petrol (litre) | 2.31 |
| Diesel (litre) | 2.68 |
| Jet fuel (kg) | 3.16 |
| Marine fuel (kg) | 3.21 |
| Natural gas (kg) | 2.75 |
Stationary Combustion
| Fuel | kg CO₂e / unit |
|---|---|
| Natural gas (kWh) | 0.20 |
| Natural gas (m³) | 2.10 |
| LPG (kg) | 2.98 |
| Heating oil (litre) | 2.96 |
| Coal (kg) | 2.88 |
Refrigerants & Fugitive
| Refrigerant | GWP (100-yr) |
|---|---|
| R-410A | 2,088 |
| R-134a | 1,430 |
| R-404A | 3,922 |
| R-32 | 675 |
| CO₂ (R-744) | 1 |
Materials & Waste
| Material / Process | kg CO₂e / kg |
|---|---|
| Steel (virgin) | 1.9 – 2.3 |
| Steel (recycled) | 0.3 – 0.5 |
| Cement | 0.9 – 1.0 |
| Aluminium (virgin) | 8.0 – 12.0 |
| Landfill waste | 0.5 – 1.0 |
Recommended Databases
These databases provide verified, regularly updated emission factors for professional carbon accounting. Always cite your source and document the factor version used.
IPCC Emission Factor Database (EFDB)
GlobalThe Intergovernmental Panel on Climate Change maintains the most authoritative global emission factors for national inventory reporting. Suitable for cross-border consistency and academic rigour.
Best for: National inventories, academic research, cross-border comparison
EPA GHG Emission Factors Hub (United States)
USThe US Environmental Protection Agency provides comprehensive emission factors for electricity, fuels, waste, and industrial processes. Updated annually and widely used for corporate reporting in North America.
Best for: US-based organisations, EPA compliance, corporate reporting
DEFRA / BEIS Conversion Factors (United Kingdom)
UKThe UK Department for Business, Energy & Industrial Strategy publishes annual conversion factors for greenhouse gas reporting. The most widely used factors for UK corporate reporting and SECR compliance.
Best for: UK organisations, SECR compliance, Streamlined Energy & Carbon Reporting
IEA Emission Factors
GlobalThe International Energy Agency provides electricity emission factors for over 190 countries and regions. Updated annually with the latest energy mix data. Essential for multinational organisations.
Best for: Multinational corporations, global Scope 2 reporting, country comparison
Ecoinvent & LCA Databases
GlobalEcoinvent, GaBi, and other life cycle assessment databases provide cradle-to-gate emission factors for thousands of products and processes. Essential for Scope 3 calculations and product carbon footprints.
Best for: Scope 3 calculations, product carbon footprints, supply chain analysis
Practical Guidance
1. Choose the Right Factor Type
- •Location-based — reflects the average emissions intensity of the grids where energy consumption occurs. Required for GHG Protocol compliance.
- •Market-based — reflects emissions from energy that companies have purposefully chosen, including renewable energy certificates and power purchase agreements. Also required for GHG Protocol compliance.
- •Residual mix — the grid emissions after accounting for tracked renewable energy. Used when market-based factors are unavailable.
2. Use the Most Recent Data
Emission factors change as grids decarbonise and industrial processes improve. Using outdated factors can significantly overstate or understate your emissions. Establish a policy to update factors annually and document the version used in each reporting period.
3. Document Your Sources
Every emission factor used should be traceable to its source. Maintain a factor register that records: the factor value, the source database, the publication year, the applicable geography, and the date it was applied. This is essential for audit trails and third-party verification.
4. Match Factors to Activity Data Precision
The precision of your emission factor should match the precision of your activity data. Using a highly precise factor with approximate activity data creates a false sense of accuracy.
| Activity Data Quality | Recommended Factor Precision |
|---|---|
| Invoice-level (exact kWh) | Country or regional grid factor |
| Utility bill (monthly totals) | National average factor |
| Estimated consumption | Regional or global average |
| Spend-based (financial data) | Sector-average emission factor |
5. Be Consistent Across Time
When tracking emissions over time, consistency is more important than precision. If you change emission factors between reporting periods, recalculate your base year using the new factors to maintain comparability. The GHG Protocol calls this "base year recalculation."
Searchable Emission Factor Database
Terrnix is building a searchable database of emission factors covering 190+ countries, all major fuels and materials, and regular updates from official sources. Filter by country, sector, and fuel type. Export directly to your carbon accounting workbook.
190+ Countries
National and regional electricity factors updated annually
All Major Fuels
Transport, stationary combustion, refrigerants, and materials
Export Ready
CSV and Excel export for direct import into your models
Related Tools & Resources
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