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A guide to fuel mixes

a row of wind turbines on a hillWhere does your electricity come from and how green is it?  

Since 2005, all UK electricity suppliers have had to tell us what makes up the electricity that comes into our homes. This is called ‘fuel mix disclosure’ and it’s a requirement of energy regulator Ofgem.

What is fuel mix?

Electricity is generated from different fuels - coal, natural gas, renewable and nuclear energy.

Your supplier’s fuel mix information shows what percentage of each resource has been used.

Green fuel 

Renewable, or ‘green’, energy comes from sources such as wind, solar and wave power, and the greener the supplier, the lower their carbon emissions.

To see how green your energy supplier is, check out the table below: the higher the renewable energy percentage, the greener the supplier.

But being eco-friendly can cost you. It’s usually more expensive to buy renewable energy because of the time and money it takes to generate, after all, windfarms are pricey to build.

The UK currently has the lowest percentage of energy sourced from renewables in the European Union. However, the government has promised to boost investment in offshore wind farms in order to hit our target of 35% by 2020.

Who are the greenest electricity providers?

It would be hard to find a greener team than Green Energy, the only UK supplier who currently get 100% of their power from renewable sources. However, most of the other energy suppliers do offer a tariff with power sourced entirely from renewables. These tariffs can be compared easily by using the 'green' filter on our energy comparsion result page.

For more information on green energy, check out’s Guide to Generating Domestic Renewable Energy.

Nuclear energy

First Utility and E.ON are the two top users of nuclear energy (28.1% and 24.8% respectively).

But nuclear power also has its critics. Fears about safety after high-profile leaks and a long-term plan for the safe disposal of nuclear waste still need to be addressed to everyone’s satisfaction.

Fuel mixes of the energy suppliers

Want to know how your supplier mixes it up? This table provides all the information you need…

Fuel mixes of the energy suppliers
Supplier Coal Natural gas Nuclear Renewables Other
British Gas 13.0% 66.0% 13.0% 6.0% 2.0%
npower 38.0% 46.0% 11.0% 3.0% 2.0%
Scottish Power 50.2% 41.9% 0.0% 7.6% 0.3%
E.ON 25.2% 35.7% 24.8% 11.2% 3.1%
SSE 25.0% 59.1% 5.5% 8.9% 1.5%
EDF 49.0% 31.0% 12.0% 6.0% 2.0%
Telecom Plus 38.0% 46.0% 11.0% 3.0% 2.0%
Ebico 25.0% 59.1% 5.5% 8.9% 1.5%
Spark 25.0% 59.1% 5.5% 8.9% 1.5%
Utilita 33.0% 39.0% 21.0% 4.0% 3.0%
Ecotricity 18.3% 24.1% 18.0% 37.4% 2.2%
Green Energy UK 0.0% 68.0%* 0.0% 32.0% 0.0%
Good Energy 0.0% 0.0% 0.0% 100% 0.0%
First Utility 28.6% 37.7% 28.1% 2.1% 3.5%
*Gas from combined heat and power (CHP), considered 'green' by Ofgem.

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