Emitrics
Last Updated: June 16, 2025Data Period: April 2023 - March 2024
Current Dataset

UK Electricity Supplier Fuel Mix & Carbon Factors 2024

About This Dataset

This dataset provides comprehensive information on the fuel mix and carbon emission factors for UK electricity suppliers for the 2024 reporting period (April 1, 2023 - March 31, 2024). It includes data on the percentage of electricity generated from different sources (coal, gas, nuclear, renewable, and other) as well as the resulting carbon dioxide emissions (in grams per kilowatt-hour) for each supplier and tariff.

Data Provenance

The data is compiled from official fuel mix disclosure information published by Ofgem (the UK energy regulator) and individual electricity suppliers. Each supplier is required by law to disclose their fuel mix and environmental impact information to customers annually. We've collected this information from supplier websites and official publications to create a centralized, accessible dataset.

Methodology

For each supplier, we've recorded:

  • The percentage of electricity sourced from coal, gas, nuclear, renewable, and other sources
  • The resulting CO2 emissions in grams per kilowatt-hour (g/kWh)
  • Nuclear waste produced in grams per kilowatt-hour (g/kWh)
  • The disclosure year and effective period
  • The data source and link to the original information

Where suppliers offer multiple tariffs with different fuel mixes (e.g., standard vs. renewable tariffs), we've included separate entries for each tariff type. This allows for more accurate carbon accounting based on the specific tariff a customer is on.

Update Cycle

This dataset is updated annually following the publication of new fuel mix disclosure data by suppliers. The UK reporting period runs from April 1 to March 31, with suppliers typically publishing their data by July each year. We aim to update this dataset by mid-year once all major suppliers have published their information.

Using This Data for Carbon Accounting

To calculate the carbon emissions from your electricity consumption:

  1. Identify your electricity supplier and specific tariff in the table
  2. Note the CO2 emissions factor (in g/kWh)
  3. Multiply your electricity consumption (in kWh) by this factor
  4. Divide by 1,000 to convert to kilograms of CO2

For example, if you used 5,000 kWh of electricity on a tariff with a carbon factor of 200 g/kWh, your carbon emissions would be: (5,000 × 200) ÷ 1,000 = 1,000 kg CO2 (or 1 tonne).

Note: For the most accurate carbon accounting, always use the specific tariff you're on rather than the supplier average. Many suppliers offer both standard and renewable tariffs with significantly different carbon factors.

UK Electricity Supplier Emission Factors

Supplier ↕️Tariff ↕️Coal % ↕️Gas % ↕️Nuclear % ↕️Renewable % ↕️CO2 (g/kWh) Source
British Gasrenewable tariffs0001000British Gas
Co-op Energyaverage0015.284.80Ofgem
e.on nextgust0001000e.on Next
e.on nextdrive0001000e.on Next
Ecotricityaverage0001000ecotricity
EDF EnergyZero carbon0010000EDF Energy
EDF EnergyRenewable0001000EDF Energy
Good Energyaverage0001000Good Energy
Green Energy UKaverage0001000Green Energy UK
London Poweraverage0015.284.80Ofgem
Octopus Energyaverage0015.284.80Octopus Energy
ScottishPowerGreen Tariffs0001000ScottishPower
Utility WarehouseGreen Tariffs0001000Utility Warehouse
e.onDomestic and Small Business0001000e.on UK
smartestenergyRenewable Tariffs0001000smartestenergy
SSE EnergyRenewable Tariffs0001000SSE Energy
British Gas BusinessRenewable Energy for Business0001000British Gas Business
British Gas BusinessZero Carbon Energy for Business0090100British Gas Business
Bryt Energyaverage0001000Bryt Energy
EngieRenewable Tariffs0001000Engie
e.on nextaverage2.19.91.585.568e.on Next
Sainsbury Energyaverage2.19.91.585.568Ofgem
Shell Energyaverage416376111.3Shell Energy
British Gasaverage4175720117Ofgem
EDF Energyaverage4.319.75420.1136EDF Energy
So Energyaverage4.922.73.566.7155.8So Energy
British Gasother tariffs628631191British Gas
British Gas Businessother tariffs628631191British Gas Business
UK Averageaverage6.33512.743.2222Ofgem
EDF Energyother tariffs83750.50.8254EDF Energy
Engieaverage837645254.75Engie
SSE Energyother tariffs010000373SSE Energy
ScottishPoweraverage1360911415ScottishPower
Boostaverage1361911417Ofgem
OVO Energyaverage1361911417Ovo Energy
Rebel Energyaverage1463108432Rebel Energy
ScottishPowerother tariffs1568110465ScottishPower
EngieStandard Tariffs1568110.5465.09Engie
Home Energyaverage14.767.910.60.2466Ofgem
Outfox the Marketaverage14.767.910.60.2466Ofgem
Tomato Energyaverage14.767.910.60.2466Tomato Energy
Tulo Energyaverage14.767.910.60.2466Ofgem
Utility Warehouseaverage14.767.910.60.2466Ofgem
Utility Warehouseother tariffs1568110.2466Utility Warehouse
e.onCorporate Customers14.767.910.60.2466e.on UK
Residual Fuel Mixaverage14.767.910.60.2466Ofgem
Eaverage14.767.910.60.2466.269E Energy
Fuse Energyaverage14.767.910.60.2469Fuse Energy
Utilitaaverage1568110473Utilita
smartestenergyother tariffs1568110473smartestenergy
Showing 50 of 50 suppliers

🌱 Cleanest UK Electricity Suppliers 2024

🏆Zero Carbon Emissions (0 g CO₂/kWh)

Ecotricity
All tariffs
100% renewable
Good Energy
All tariffs
100% renewable
Green Energy UK
All tariffs
100% renewable
Bryt Energy
All tariffs
100% renewable
British Gas
Renewable tariffs
100% renewable
EDF Energy
Renewable tariffs
100% renewable
ScottishPower
Green tariffs
100% renewable
e.on
Domestic & Small Business
100% renewable

These suppliers provide 100% renewable electricity through wind, solar, and hydroelectric sources.

Lowest Non-Zero Emissions

e.on next
Average
68 g CO₂/kWh
85.5% renewable
Shell Energy
Average
111.3 g CO₂/kWh
76% renewable
British Gas
Average
117 g CO₂/kWh
20% renewable
EDF Energy
Average
136 g CO₂/kWh
20.1% renewable
So Energy
Average
155.8 g CO₂/kWh
66.7% renewable

These suppliers offer the lowest emissions among mixed-source tariffs, well below the UK average of 222 g CO₂/kWh.

⚡ How much difference does supplier choice make?

0 g
Best suppliers (100% renewable)
68-156 g
Low-carbon suppliers
222 g
UK average

Impact example: For a typical home using 3,000 kWh annually, switching from the UK average to a 100% renewable supplier saves 666 kg CO₂ per year - equivalent to driving 1,500+ miles less.

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