What does “fuel mix” mean?

A supplier’s fuel mix shows the sources of the electricity that it supplies to its customers e.g. coal, gas, nuclear and renewables.

Over the course of a year, energy suppliers must purchase sufficient electricity to feed into the national electricity grid to cover the amount their customers take out. At the end of each year, suppliers must disclose their fuel mix to the electricity and gas regulator, Ofgem. This information is published annually to help consumers make informed choices about their electricity supplier.

For further information on the impacts of the UK average fuel mix see https://www.gov.uk/government/collections/fuel-mix-disclosure-data-tables

For further information on the health and environmental impacts of coal, gas and nuclear see:
– Coal (toxic air pollution): https://www.ukhealthalliance.org/wp-content/uploads/2016/10/UK-Health-Alliance-A-Breath-of-Fresh-Air-Final-Report.pdf
– Gas (emits CO2): https://www.ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_wg3_ar5_chapter7.pdf
– Nuclear (radioactive waste): https://ukinventory.nda.gov.uk/about-radioactive-waste/how-is-radioactive-waste-produced/


The information in the table below covers our supply licence for Symbio Energy Ltd for the period from April 2016 to March 2017.

 Fuel Mix for 1st April 2016 to 31st March 2017 ENVIRONMENTAL IMPACT
Energy SourcesCoalNatural GasNuclearRenewablesOther FuelsCarbon Dioxide Emissions (g/KWh)Radioactive Waste (g/KWh)
Symbio Energy Ltd.6.4%19.6%5.4%66.5%2.1%1410.0003
UK National Average*8.5%44.1%21%24.2%2.2%2540.00147

*Figures provided by the Department for Business, Energy and Industrial Strategy (BEIS).

Fuel Mix Data
Natural Gas
Other Fuels

Carbon Dioxide Emissions (g/KWh): The weighted average of the carbon dioxide emitted in the production of electricity from each fuel source. This is calculated on the basis of figures provided by BEIS (details of these can be found at the BEIS website).

Radioactive Waste (g/KWh): The radioactive waste, being fuel burnt in the reactor to be subsequently discharged as spent fuel. This is calculated on the basis of figures provided by the DECC (details of these can be found at the BEIS website).