The Energy System of the United Kingdom


The UK’s supply of energy from coal has plummeted, and that from oil, gas and renewables has recently grown. Between 2010 and 2017 (the most recent year of free IEA data, and the only with sufficient detail), non-hydro renewables grew from a 1% share to 8%, nuclear grew from 7% to 9%, biofuels grew from 3% to 7% and fossil fuels reduced from 88% to 76%.

The steep reduction of coal fired electricity grabbed the headlines. The rate of this reduction was consistent from 1990 onwards, except for a brief peak in 2005. Over this period electricity demand increased, and the reduced coal-fired capacity was replaced by that from gas, wind and biofuels.

Electricity generation from biofuels tripled between 2010 and 2017. The UK is the world’s largest importer of wood pellets (a biofuel), sourced from the forests of the SE US. Four of the six furnaces of UK’s largest coal fired power station, Drax, were converted to burn wood pellets, and the emissions from this combustion are not tallied, nor are they tallied by the US. This results in an under-reporting of the UK’s CO₂ emissions and consequently, the carbon intensity of their energy supply (i.e. carbon emitted per unit of energy supplied).

Placing aside the obfuscation of carbon accountancy caused by biofuel energy, the data shows the carbon intensity of the UK’s energy supply has only lowered to world average, despite the UK’s CO₂ emissions from fossil fuels having declined by 30% between 2008 and 2018.1 The UK’s energy supply in 2017 remained highly fossil fuelled.


The following preface is used on all posts on this site about energy systems, so you may wish to skip down to The UK’s Energy Supply.

This site uses data from the IEA2 and BP.3 The latest year of BP’s data is 2018, whereas the IEA’s is 2017. Despite this, some charts here use IEA data because BP doesn’t fully account for solid biofuels, and in some instances doesn’t provide adequate detail.

A conventional representation of an energy system is shown below.

Figure 1. Representation of an energy system.

The term ‘total primary energy supply’ (TPES) describes, or accounts for, energy in its primary form prior to any conversions such as coal to electricity, whereas energy in forms purchased and used by the consumer, such as electricity, is accounted for separately as ‘total final consumption’ (TFC). For simplicity this site uses the terms ‘energy supply’ and ‘energy consumption’ respectively. Information about electricity is shown at the bottom of this page.

Energy supplied by renewables (shown as non-combustibles in the above diagram) cannot be directly compared with energy supplied by fossil fuels because renewables have natural forms of primary energy (i.e. sun, wind etc). For example, the quantity of kinetic energy in wind can’t be directly measured and compared to the quantity of coal or other combustible fuels. To overcome this, for each renewable energy source, an equivalent quantity of primary energy is determined. This allows the primary energy supplied by both combustible and non-combustible (i.e. renewable) energy sources to be compared. This is conventionally done by calculating for each quantity of renewable electricity, the quantity of primary energy that would be required to be input to a thermal (fossil fuelled) power station of average efficiency, in order to output an equivalent amount of electricity. This method therefore describes the quantity of fossil fuels displaced by renewables, and is explained further in the post About Energy Systems.

The UK’s Energy Supply

Most of the UK’s energy is supplied by gas.4

The UK’s energy supply is shown below in chart 1, and in expanded form in chart 2. It’s important to note that in the UK’s case, IEA data reveals that about half of the energy shown by BP to be from renewables is from bioenergy, which as explained further below, is not all carbon-neutral.

Chart 1. UK’s energy supply, 1990 to 2018. Data: BP(2019).3 Shaded bars indicate years 2017 and 2018. Note: (i) BP’s definition of Renewables is energy supplied by Solar, Wind, Geothermal, Solid Biofuels & ‘Other’; (ii) BP does not fully account for biofuels; and (iii) Solid biofuels may not be carbon-neutral.5
Chart 2. UK’s energy supply, 1990 to 2018, expanded. Data: BP(2019).3 Shaded bars indicate years 2017 and 2018. Note: (i) BP’s definition of Renewables is energy supplied by Solar, Wind, Geothermal, Solid Biofuels & ‘Other’; (ii) BP does not fully account for biofuels; and (iii) Solid biofuels may not be carbon-neutral.5

The obvious decline of coal is due to a decline of energy consumption by UK industry, and the replacement of coal with gas, bioenergy and wind for electricity generation.

Charts 3 and 4 show the UK’s energy supply by share, that in 2017 was 76% fossil fuelled. Note that although IEA data used here is one year older than BP’s above, it reveals the share of energy from biofuels and waste.

Chart 3. UK’s energy supply by share in 2017. Data: IEA.2
Chart 4. UK’s energy supply by share. Data: IEA.2

Numerical values are shown below.

Table 1. UK’s energy supply. Data: IEA.2 Dashes indicate negligible or zero values.

The UK’s consumption of biofuels results in false carbon accountancy:5 The UK is the world’s largest importer of biofuel wood pellets,6 and emissions from burning biofuels is reported in the land-use sector only, not the energy sector, and only by the country supplying the biofuel. Furthermore, countries such as US, Canada and Russia which are all significant exporters of biofuels, do not account for the carbon emissions of biofuels.5 By converting coal fired power station furnaces to instead burn biofuels, as has been done in 4 of the 6 units of Drax power station (the largest in the UK)7 and then importing the biofuel from the US, the UK government has literally been able to clear these emissions from its tally, and now are not tallied in any country at all. It’s a massive lie. The map below from Drax shows their biofuel supply operations in the US.

In 2017, 4 million tonnes of wood pellets was exported from the US to the UK,8 and according to Drax, 20 thousand tonnes arrives every day (20 thousand tonnes/day × 5 days/week × 52 weeks/year = 5.2 million tonnes/year).9 In 2018, 66% of bioenergy in the UK was generated by combusting plant biomass, which is a general term encompassing wood pellets. 10

Drax power station.11

Is burning wood really carbon neutral?  
Southern forest ecosystems do a lot for both people and wildlife. But perhaps most valuable today is their role in storing carbon. And on that key point, critics take strong exception to the industry’s claim that wood pellets are a carbon neutral fuel.
“That’s just not correct,” says John Sterman, a professor at MIT’s Sloan School of Management who recently published a lifecycle analysis of wood bioenergy.
“What we found is that contrary to your intuition, burning wood to make electricity in places like the Drax power plant actually makes climate change worse for the rest of the century” Sterman says.

The UK’s move away from coal means they’re burning wood from the US, Public Radio International (PRI).8

The UK’s annual territorial fossil fuel (i.e. energy related) CO2 emissions are shown below. The decline shown in (a) is not entirely factual due to the false carbon accountancy of biofuels described above.

Chart 5.(a) The UK’s annual fossil fuel CO2 emissions. Data: BP(2019).3 (b) The UK’s fossil fuel CO2 emissions by source from 1959 to 2018. Data: Global Carbon Project.12 Flaring emission data only shown for years 2000 to 2018.

A measure of carbonisation is the carbon intensity of the energy supply, which is the mass of carbon dioxide emitted per Joule of energy supplied. This is shown below for the UK, the world and other countries discussed on this site. This calculation depends on reported CO2 emissions described above, so actual values of the UK’s carbon intensity will be higher.

Chart 6. Carbon intensity of UK’s energy supply. Data: IEA.2

The UK’s Energy Consumption

The London skyline.13

As shown in figure 1 above, energy consumption describes energy after conversions. For example, some energy supplied by coal is converted and consumed as electricity, and the rest is instead combusted and consumed in industrial applications (e.g. steel manufacture) and domestic applications (e.g. cooking). The UK’s energy consumption is shown below.

Chart 7. UK’s energy consumption by share in 2017, showing electricity generation. Data: IEA.2 The dashed segment in the left hand most pie chart represents the equivalent share of electricity if the quantity produced in 2017 was produced within a 100% wind/water/solar (WWS) energy system, serving to demonstrate the remaining change needed for full electrification. The 21.6% in 2017 equates to 50.3% under WWS, as shown. The share of electricity becomes greater because total energy consumption of a 100% WWS system reduces to 42.9% of business-as-usual.14 15 This is due to: (a) using heat pumps for building heat; (b) using electricity for industrial heat; (c) using battery and hydrogen fuel cell vehicles; (d) eliminating mining, transportation and processing of fuels, and (e) efficiency improvements. Also note: (i) Non-energy use of energy sources excluded (e.g. oil used for lubrication); (ii) Transport & Distribution Losses include gas distribution, electricity transmission, and coal transport, and (iii) Examples of Electricity Industry Own-Use include energy consumed in coal mines, own consumption in power plants and energy used for oil and gas extraction.16

Chart 8 shows electricity generation by share for year 2018 using BP data.

Chart 8. Electricity generation in the UK, 2018. Data: BP(2019).3 Note: (i) BP’s definition of Renewables is energy supplied by Solar, Wind, Geothermal and Solid Biofuels; (ii) BP does not fully account for biofuels; and (iii) Solid biofuels may not be carbon-neutral.5

The diversity of the UK’s electricity generation technology is broad, consisting in 2018 of 1,085 seperate generators with a total capacity of 79.4GW,17 and an additional 17.5GW of overseas electricity interconnectors planned, of which 5GW is now operational. The planned total capacity of the interconnectors will be equivalent to 22% of the UK’s total capacity, and when complete, the UK’s grid will be connected to that in Norway, Denmark, Germany, The Netherlands, Belgium, France and Ireland.

UK overseas electricity interconnectors showing operating (5GW), under construction (3.4GW) and planned (9.1GW).18 Total interconnector capacity is planned to be 17.5GW. In comparison, this is 22% of total installed electricity capacity in the UK in 2018 of 79.4GW.19

Chart 9 shows electricity generation over time.

Chart 9. Electricity generation in UK. Data: IEA.2

The total installed capacity of wind electricity generation in 2018 was 8.9GW onshore and 7GW offshore,20 and as shown in the charts above, in 2017 generated 14% of the UK’s electricity.

Sheringham Shoal Offshore Wind Farm21 22

As shown above, for about the past three decades nuclear energy has accounted for about 9% of the UK’s energy supply and 20% of electricity.

Worldwide there are 449 nuclear reactors,23 and in 2018 nuclear power stations produced 10% of the world’s electricity.3

The UK established the world’s first civil nuclear programme24 and has fifteen operational nuclear reactors.25 All but one are planned to be closed by 2030, with eleven before 2025. One nuclear power station, known as Hinkley Point C,26 is being constructed in the UK at Hinkley Point in Somerset. Also at this location is the disused Hinkley Point A27 and the still operational Hinkley Point B28 nuclear power stations. Hinkley Point C is being constructed by Électricité de France (EDF), 83% owned by the French government, and China General Nuclear Power Group (CGN), a state-run Chinese energy company. CGN took a 33.5% stake in the project, which will be the first new nuclear power station to be built in the UK in almost 20 years and will provide about 7% of the country’s electricity.29

Hinkley Point C is a third generation (‘generation three’)30 pressurised light water reactor (PWR) design known as a European Pressurised Reactor, or Evolutionary Power Reactor (EPR).31 Generation three designs of nuclear power stations include developments of generation two nuclear reactors that were built up to the late 1990s. These developments include (i) improved fuel technology, (ii) longer operating life, (iii) improved thermal efficiency, (iv) significantly enhanced safety systems (including passive nuclear safety), and (v) standardised designs for reduced costs.30

Hinkley Point C will consist of two EPR reactors each with a capacity of 1,600 MW. Taishan 1 in China was the first EPR to begin operation, in June 2018.32 Three other commercial EPR units currently being built: Olkiluoto Nuclear Power Plant in Finland, Flamanville Nuclear Power Plant in France, and Taishan 2 in China.

View east from Dunkery Beacon on Exmoor, towards the Somerset coast. Hinkley Point is visible in the distance.33

Charts 10 and 11 compare electricity generation for years 2017 and 2018. Although BP classify hydro separately from renewables, it’s of course also renewable.

Chart 10. Electricity generation in the UK, years 2017 & 2018. Data: BP(2019).3 Note: (i) BP’s definition of Renewables is energy supplied by Solar, Wind, Geothermal, Solid Biofuels & ‘Other’; (ii) BP does not fully account for biofuels; and (iii) Solid biofuels may not be carbon-neutral.5 About half of the energy in the UK from non-hydro renewables is from biofuels, two-thirds of which is from plant-biomass.
Chart 11. Electricity generation in the UK, expanded, years 2017 & 2018. Data: BP(2019).3 Note: (i) BP’s definition of Renewables is energy supplied by Solar, Wind, Geothermal, Solid Biofuels & ‘Other’; (ii) BP does not fully account for biofuels; and (iii) Solid biofuels may not be carbon-neutral.5 About half of the energy in the UK from non-hydro renewables is from biofuels, two-thirds of which is from plant-biomass.

The following two charts below show the UK’s energy consumption over time by energy source and economic sector.

Chart 12. UK’s energy consumption by: (a) Energy source; (b) Economic sector. Data: IEA.2

Finally, the following charts show energy consumption in each economic sector. Most consumption is gas and oil, in the residential and transport sectors respectively.

Chart 13. Energy consumption in economic sectors. Note: The transport sector includes rail and aviation. Gridlines removed for clarity. Data: IEA.2
  1. (563MtCO₂ – 394MtCO₂) / 563MtCO₂()
  4. British Gas,
  10. 22,897/34,758 =  66%, Capacity of, and electricity generated from, renewable sources (DUKES 6.4),
  11. Photo by Harkey Lodger,,, CC BY-SA 3.0.()
  13. Photo by Kloniwotski,, CC BY-SA 2.0.()
  19. para 5.54,
  20. Database page, sorted by installed capacity,
  22. Photo by
  33. Photo by Nilfanion,, CC BY-SA 3.0.()