All UK energy suppliers are required to publish information about their energy fuel mix annually. A supplier’s fuel mix is the ratio of different energy sources or ‘fuels’ that the supplier uses to generate its customers’ electricity.
This ratio is made of up the following fuels:
- Coal
- Natural gas
- Nuclear
- Renewables (such as solar, wind and biomass)
- Other
The table below shows you how the UK’s average energy fuel mix has changed over the past decade:
| 2016-17 | 2020-21 | 2021-22 | 2022-23 | 2023-24 | |
|---|---|---|---|---|---|
| Coal | 9% | 2.7% | 3.8% | 3.4% | 6.3% |
| Natural gas | 44% | 38.2% | 38.5% | 39.3% | 35% |
| Nuclear | 21% | 16.1% | 16.1% | 13.9% | 12.7% |
| Renewables | 24% | 40.3% | 38.7% | 40.8% | 43.2% |
| Other | 2% | 2.7% | 2.9% | 2.6% | 2.8% |
The most recent fuel mix can be found on GOV.UK. This covers the period 1 April 2023 to 31 March 2024. The 2024-25 figures are due to be published on 1 August 2025.
The figures reveal that while coal and natural gas usage have declined since 2016-17, their use has stabilised over the past few years. The proportion of energy provided by nuclear has also fallen significantly during this period, while renewables has plateaued after jumping significantly from 2016-17 to 2020-21.
You can compare this to your supplier’s specific fuel mix using its website or the table below.
Fuel mix by supplier
All UK energy suppliers update their fuel mix figures annually. Ofgem, the energy regulator, requires all electricity suppliers in the UK to tell customers where they get their fuel and how that is broken down by percentage.
The following table reveals what fuels provide electricity supplied by the UK’s big six energy companies:
| Supplier | Coal | Gas | Nuclear | Renewables | Other |
|---|---|---|---|---|---|
| British Gas | 4% | 17% | 57% | 20% | 2% |
| EDF Energy | 4.3% | 19.7% | 54% | 20.1% | 1.9% |
| E.ON Next | 2.1% | 9.9% | 1.5% | 85.5% | 1% |
| Octopus | 0% | 0% | 15.2% | 84.8% | 0% |
| OVO | 13% | 61% | 9% | 11% | 6% |
| ScottishPower | 13% | 60% | 9% | 11% | 7% |
The figures supplied by each company only tells part of the story. What fuels are used to supply your home are dependent on what electricity tariff you’re on.
What is British Gas's fuel mix?
While British Gas’s overall fuel mix is predominantly made up of renewables and nuclear, non-renewable tariffs are predominantly sourced from nuclear (63%) and natural gas (28%) sources. Customers can also sign up for renewable tariffs that use 100% renewable electricity.
What is EDF Energy's fuel mix?
EDF Energy offers a range of tariffs. Its Zero Carbon tariff is sourced entirely from nuclear energy, while its Renewables tariff is powered from 100% renewable sources.
What is E.ON Next's energy fuel mix?
E.ON Next offers two residential tariffs that are powered exclusively from renewable sources: Next Gust and Next Drive.
What is Octopus Energy's fuel mix?
Like E.ON Next, the vast majority of Octopus’s fuel mix is derived from renewable sources. The rest of its electricity comes from another zero-carbon source: nuclear.
What is OVO Energy's fuel mix?
OVO Energy's fuel mix shows a large reliance on natural gas, which makes up over 60% of its total. The company claims its fuel mix is more accurate than others because it’s stopped buying REGO certificates to boost its renewable energy figures.
What is ScottishPower's fuel mix?
ScottishPower only supplies renewable energy to those on its Green Tariffs. If you’re on a ScottishPower Green Tariff then your electricity comes from 100% wind power generated by its own windfarms. If, however, you’re on another tariff, then none of your electricity is renewable – it’s primarily gas (68%) followed by coal (15%) and nuclear (11%).
What are the differences between the fuel types?
The average UK energy mix primarily comes from a combination of coal, natural gas, renewables and nuclear. Here’s a breakdown of the pros and cons of each type of fuel used in the UK's energy supply:
Natural gas and coal energy
Coal is a major contributor to global warming while there are concerns over the use of fracking to extract natural gas. Both are also non-renewable, and extraction won't get easier as the number of locations to drill in reduce.
Nuclear power energy
Nuclear energy is relatively environmentally friendly in that it emits no greenhouse gases, making it a zero-carbon energy source. It’s also cheap, reliable and always available once set up. However, new plants are costly and slow to set up due to all the safety measures and permissions required. There’s also a question mark over the disposal of the radioactive waste generated from nuclear energy. Both transportation and disposal add additional costs and pose extra risks to the environment.
Renewable energy
Generally, all renewable sources are clean and sustainable, meaning they can continuously be used at little cost. Wind turbines and solar panels are relatively cheap to build and inexpensive to maintain. However, bigger solar and wind installations require a lot of land to create the significant amounts of energy required to power the UK’s national grid.
There are multiple sources where UK suppliers get their renewable energy from, including:
- Wind energy
- Solar energy
- Biomass energy
- Hydro energy
- Landfill waste energy.
Switching energy mixes
Once you’ve determined what fuel sources your current tariff and supplier are using with the help of this guide, you can decide if you want to stick with your current plan or try something new. Why not compare your current deal with other energy plans and providers in your area to see if you can find a cheaper plan on a different fuel mix?
What will the UK energy mix be in future?
Although the growth of renewable energy has stalled in recent years, it’s possible that the UK government’s establishment of Great British – or GB – Energy will restart expansion in renewable energy projects such as wind (offshore and onshore), solar and hydro. GB Energy’s stated aim is to help transform the UK into a “clean energy superpower”.
Many major UK energy suppliers have also been making good on their promise to invest heavily in renewable energy sources. One reason is that, unlike fossil fuels or nuclear, renewables won’t run out. Also, once set up, renewable energy plants become self-financing. As a result, rather than make vague promises about where their electricity comes from, companies can point to the fact that they generate at least some of the renewable electricity they sell themselves. For example, ScottishPower sources all its renewable electricity from its own windfarms, while Octopus claims to operate enough renewable generation plants to power four million homes.
However, the UK is unlikely to be fully powered by renewable energy soon. Due to the technological advancements made in being able to locate and extract natural gas at an affordable rate, we will likely see it continue as the UK's main alternative to renewables for quite some time to come.
