Energy Fuel Mix Explained

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Our green energy fuel mix is the fuels that are utilised to generate the electricity that powers our homes. For years, we got nearly all of our energy from burning fossil fuels like coal, oil, and gas. However, in recent years, renewable energy fuels have also become much more commonly utilised to generate energy. These fuels make up what is known as our national energy mix. In this article, we’ll look at everything you need to know about our UK energy mix, the energy fuel mix of different suppliers, and where different suppliers get their energy from.
Last update: November 2022

As you may have heard on the news, the UK energy market is currently under an immense amount of stress as a result of a global gas shortage driving up costs and putting several energy suppliers out of business. To learn more about this and stay updated on a daily basis you can read our page on the UK energy crisis.

What does energy mix mean?

Right now, there’s electricity from all kinds of sources surging through the national grid. Some of it is renewable. Some of it comes from fossil fuels. It all gets mixed up together in our country’s network of cables and wires.

Of course, when we use our electricity, the fuels that generated it make no difference to us. But they can make a big difference to the planet. Let’s examine our nation’s energy fuel mix and why it’s so important if we’re to meet our environmental targets going forward.

What is an energy fuel mix?

An energy fuel mix is the combination of different fuels that generate all the electricity that flows through the national grid. This is known as our national energy fuel mix.

Energy suppliers buy electricity wholesale from a range of different sources (and some of the larger suppliers generate their own). Many suppliers buy wholesale energy from a range of sources. As such, different suppliers have different energy fuel mixes of their own. Ofgem dictates that energy suppliers are required to disclose their energy fuel mix so that consumers can see how green they are.

The primary sources of energy in the UK are:


Coal’s proportion of the energy fuel mix has been steadily shrinking over the past two decades as we have shifted towards more sustainable forms of energy generation. Coal is one of the “dirtiest” fossil fuels, producing just over 400g of carbon per kWh of electricity.


Gas is still the largest component in our country’s energy mix, and made up 41% in Q3 of 2020 (the most recent figures available at the time of writing). Although gas is still a fossil fuel, it burns much more cleanly than coal or oil.


Nuclear power is emissions-free and, despite some high profile mishaps like Chernobyl and Fukushima, very safe. However, because it uses finite natural resources like uranium, it is not technically renewable.


Finally, a growing proportion of the UK energy mix comes from renewables. In 2020, our generation of renewable energy skyrocketed. Soon it is expected to make up the lion’s share of our energy mix.

What are the differences between the different renewable fuel types? Pros & cons

Renewables will soon account for the majority of our energy mix, with Ofgem ensuring that energy suppliers incorporate renewables into their own energy mixes. But what are the different renewable fuel types? What are the differences between them? And what are the pros and cons of each.

Let’s take a closer look:


Wind makes up the highest proportion of our renewable energy mix. The UK is actually the biggest generator of wind energy in the world. We have 2,450 wind farms across the country, sharing 10,420 wind turbines between them. Combined with the domestic wind turbines used by homes and small businesses, this gives us an operational capacity of over 24,000 megawatts. That’s enough to power around 4.5 million homes.

You can see the pros and cons of wind energy in the table below:

Wind Energy Pros Wind Energy Cons
It's cheaper than ever to generate. Even cheaper than natural gas Potentially disrupts the view of the British countryside
Saves on millions of tonnes of CO2 every year New wind farms require significant upfront investment
The land between wind turbines can be used to grow crops or even raise cattle Wind turbines are dependent on the whims of the weather
Allows the UK to generate more of its own energy and rely less on imports
Creates jobs and drives innovation


Upwards of 800,000 UK homes are fitted with photovoltaic (PV) solar panels. Combine these with the 425 solar farms around the nation and we have a combined solar energy capacity of 72.2 megawatts. Domestic solar panel users feed energy back into the national grid. Their suppliers pay them for this energy via an initiative called the Smart Export Guarantee. You can read more about it here.

You can find out more about the pros and cons of solar energy here:

Solar Energy Pros Solar Energy Cons
Very clean with no emissions or by-products Solar panels are expensive to install
It allows homes that are off the grid to generate their own clean energy Solar panels are reliant on the weather, and the UK isn't known for its climate
Domestic PV solar panels are recyclable Solar panel manufacture can result in carbon emissions and toxic waste water
Solar panels are low maintenance. Even at scale
The solar energy industry creates tens of thousands of new jobs per year.

Hydroelectric power

Hydropower may not make up much of our energy mix, but it’s often called upon to generate energy at short notice. And because it uses the natural flow of our waterways, it’s less weather-dependent than wind and solar power.

Although it currently makes up around 1.12 tWh of our national energy mix, it’s a very reliable and clean way to generate energy.

You can see some of the pros and cons of hydropower in the table below:

Hydropower Pros Hydropower Cons
Highly efficient. 90% of kinetic energy is turned into electricity Decaying vegetation from runoff can generate greenhouse gases
Cheap to generate Limited as there are relatively few bodies of water in the UK
Less reliant on weather than solar or wind Hydropower plants can be costly and time-consuming to build
Easier to store energy than other renewables


Finally, biomass involves the burning of renewable sourced wooden pellets. While this does have a carbon footprint, it is negated by the planting of new trees to create more biomass materials. It also helps to combat the growing problem of waste wood in the UK, of which we send around 8.5 million tonnes to landfill every year.

Let’s take a look at the pros and cons of biomass in the table below:

Biomass Pros Biomass Cons
Helps to combat the problem of waste wood Has more of a carbon footprint than other renewables
Reduces our reliance on fossil fuels Biomass boilers may be impractical in many domestic settings due to their size
Highly reliable and efficient Can be costly to implement
Domestic biomass boilers can be used to reduce our reliance on natural gas

What is the UK’s energy mix?

The UK’s energy mix is always changing, with different fuels making up a different proportion of our energy mix with each quarter.

At the time of writing, the most recent reporting of our national energy mix comes from Q3 2020. In the table below you can see various energy fuels and how much in tWh they contributed to our national energy mix:

Energy Fuel Contribution to Energy Mix in tWh
Coal 0.49
Oil 0.20
Gas 29.73
Nuclear 9.93
Hydro 1.12
Wind & Solar 18.91
Biomass 8.77
Other fuels 1.38
Imports 2.36

How much of our energy comes from renewable sources?

In Q3 of 2020, renewables accounted for 40% of our energy fuel mix with nearly 29 terawatt hours of energy coming from solar, wind, hydro and biomass.

How did it evolve over time? What is it going to be in the years to come?

Despite a few peaks and troughs, renewables have become a growing proportion of our national energy mix since the turn of the millennium, reaching an all-time high in 2020. As Ofgem continues to make our energy industry more sustainable, and consumers show more demand for green energy, we can expect renewables to become the biggest part of our energy fuel mix in the coming years.

The UK, along with other countries around the world, is aiming to make our energy industry 100% renewable by 2050. Sounds like a pipe dream? Not at all! There are several nations that already have a completely renewable energy sector.

What is the energy mix of the main suppliers?

Every energy supplier has its own energy fuel mix. It’s important to remember that even though a supplier may offer a 100% renewable energy tariff, this doesn’t necessarily mean that they have a 100% renewable energy mix.

There are too many suppliers to provide every supplier’s energy mix. However, we can provide energy mixes for the “Big 6”. These are the 6 biggest suppliers in the country (although 2 of these are in the process of amalgamating). Between them, they supply roughly 70% of the UK’s energy.

British Gas

British Gas is the UK’s biggest energy supplier, and their energy mix has grown increasingly renewable in recent years. Their energy mix is currently:

  • 76% renewables
  • 24% nuclear

Scottish Power

Scottish Power’s energy mix is as follows:

  • 5% coal
  • 50% gas
  • 6% nuclear
  • 36% renewables
  • 4% other

E.On / N Power

E.On and N Power are currently in the process of amalgamating. Although the N Power brand is still active, it will soon be completely subsumed by E.On. Their energy mix is as follows:

  • 6.2% coal
  • 70.5% gas
  • 8% nuclear
  • 10.2% renewables
  • 5.1% other


Part-owned by the French government, most of EDF’s energy comes from nuclear and renewables, although there are still some fossil fuels present in their energy mix, which is currently as follows:

  • 3.5% coal
  • 9.3% gas
  • 66.6% nuclear
  • 20.5% renewables
  • 0.1% other


Scottish supplier SSE generates its own renewable energy as well as buying it wholesale. It’s energy mix is as follows:

  • 48.1% gas
  • 51.9% renewables

Which suppliers have the most renewable energy mix?

If you’re looking for a more renewable energy supplier, there are many more options outside of the “Big 6”. The following energy suppliers all offer 100% renewable electricity as standard. They also offer either carbon-offset natural gas or carbon-neutral biomethane gas (or a combination of the two).

The greenest energy suppliers are as follows:

  • Bulb
  • Ecotricity
  • Good Energy
  • Green Energy UK
  • Pure Planet

Generation of electricity around the world

Renewables aren’t just becoming a bigger part of the UK’s energy mix. They’re a growing presence all over the world. But which countries have the greenest energy mix?

These are as follows:


Iceland both consumes and produces the most renewable electricity in the world. It also produces more energy per person than any other country, generating 19 tWh is per year. That’s 55,000 kWh per person, almost 10 times the EU average of 6,000 kWh per person.

energy mix


Norway comes in at a close second, producing 98% of its energy from renewable sources. Most of Norway’s energy comes from hydropower, with wind and geothermal energy also major contributors to its energy mix.


Finally, Kenya earns the bronze medal, with 70% of its Kenya’s energy mix coming from renewables.

Let the Papernest team find the perfect energy mix for your home

As we’ve established, every supplier has a different energy mix. If renewables are important to you, don’t worry. They needn’t come with a higher price tag.

Call the Papernest team today on 0330 818 6225 and let us find the supplier and tariff with the perfect energy mix for your home.

We’re available from 8am to 6pm.

Would you like to know more about green energy? Great! Check out these related articles:

  1. Compare green energy suppliers
  2. Best green energy supplier
  3. Home energy

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What is an energy mix?

An energy mix is the combination of fuels that are used to generate the electricity that we use in our homes and businesses.

Where do we get our energy from?

Most of the energy used in the UK is generated right here. In Q3 of 2020, only 2.36 tWh of energy came from imports.

What are the primary sources of energy in the UK?

In the UK most of our energy comes from natural gas. However, around 40% of our energy mix comes from renewable sources like hydropower, solar, wind and biomass. The rest comes from nuclear, coal, oil and imported energy from overseas.

Who are the country’s greenest suppliers?

There are many energy suppliers in the UK that provide 100% green electricity as well as carbon-neutral or carbon-offset gas.

These include:

  • Bulb
  • Ecotricity
  • Good Energy
  • Green Energy UK
  • Pure Planet

Updated on 11 Nov, 2022

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