The UK Electricity Generation Mix: What Powers the Grid Today

Britain's electricity now comes from two roughly equal halves: a renewable and nuclear half, and a gas half that is shrinking but still sets the balance on any given day. Gas supplies about one third of UK electricity¹. Official statistics for the three months from September to November 2025 put gas at 33.3% of generation by Major Power Producers, with fossil fuels as a whole at 33.4%². A published UK fuel mix for April 2024 to March 2025 gives renewables 42.1%, natural gas 33.3%, nuclear 16.2%, coal 5.9% and other sources 2.5%³.

On a calendar-year basis for 2024, 51% of UK electricity generation came from renewable sources and 14% from nuclear⁴. Gas was the largest single source of electricity generation until 2024, when wind overtook it⁵. That ordering matters less than the daily swing: gas supplies around a quarter of generation on a good day and up to 60% depending on the day⁶.

This page sets out the published shares, why different official and independent figures disagree, what moves the mix hour by hour and season by season, how the picture differs across the four nations, the rules that govern what is reported and what is built, and what the whole thing does, and does not do, for a household's energy independence. For the wider picture of where the fuel itself originates, see UK energy supply.

The headline shares, and why the published numbers differ

There is no single correct percentage, because the published series measure different things. Some count generation by Major Power Producers, the large licensed generators, which excludes a great deal of embedded and small-scale output. Some count all UK generation. Some count electricity demand met, which includes imports over interconnectors. And the reporting periods differ: calendar years, rolling supply years from April to March, and rolling three-month comparisons.

The same April 2024 to March 2025 fuel mix is published independently as renewables 42.1% and natural gas 33.3%¹², which is the figure a household is most likely to meet, because it is the basis on which suppliers describe the electricity they sell. Elsewhere nuclear is described as contributing around 20% of generation¹³, and in 2023 nuclear was 14.2% of UK electricity¹⁴. These are not errors so much as different denominators and different years; where a figure matters, its period and its measure matter with it.

Total generation is falling even as demand for electricity in some sectors rises. The UK produced 294.1 TWh in 2023 and 285 TWh in 2024⁹, and in 2024 generated 10.85% less electricity than in 1990, with over a third of that energy coming from wind and solar⁹. Renewables generated 57% more electricity than fossil fuels in 2024¹⁵. Renewable output more than doubled from 65 TWh in 2014 to 143 TWh in 2024, a rise of 122%¹⁵.

How far the mix has moved since 2012

The scale of the change is clearest against the old baseline. In 2012 the UK fuel mix was gas 39.3%, nuclear 27.5%, coal 19.4%, renewables 11.3%, oil 1.5% and other 1%¹⁶. Zero-carbon sources were less than 20% of Britain's electricity mix in 2010³.

Coal has gone from the second largest source to a residual, and the nuclear fleet has shrunk in share as reactors closed: nuclear was 26.9% of generation by Major Power Producers in June 2017², 27% in 2019¹⁷, and 16.6% in the period to May 2026⁷. Renewables have travelled the opposite way, from 11.3% in 2012¹⁶ to 23% in 2019¹⁷ to 51% in 2024⁴. Gas held a steady middle: dominant for electricity generation since 2008¹⁸, 46% of electricity generated in 2019¹⁷, 40% as of early 2022¹⁷, over a quarter in 2025⁵.

The UK has around 80GW of electricity generating capacity¹⁶. The move from a coal and gas fleet to a wind and solar one changes what that capacity means, because a gigawatt of wind and a gigawatt of gas do not produce the same energy in the same hour.

What drives the mix hour by hour and season by season

Annual percentages hide the thing that actually determines what is on the grid at any moment: weather and demand. Wind and solar run when the resource is there. Nuclear runs close to flat. Gas fills what is left, which is why its share ranges from around a quarter to up to 60% depending on the day⁶.

Solar is the sharpest illustration of that swing. Solar power in Great Britain rose by a third in the first six months of 2025 to produce a record 9.91 TWh, up 32%, breaking generation records for five months in a row since March 2025¹⁹. A record for the highest level of solar on the grid, 14 GW, was set on 8 July 2025, 44% higher than the peak five years earlier¹⁹. Output has since reached a maximum of 15,427MW on 12 July 2026, and the record for power generated from embedded solar stands at 16.3 gigawatts, set at 12.30pm on 23 April 2026²⁰. Solar's record share of generation is 19.5%, set on 24 May 2026²⁰. None of that happens at 6pm in January.

Wind and solar are complementary rather than coincident, which is what makes the combined share stable. Only 2% of days in a typical year have both low wind generation and low solar generation, measured from January 2017 to June 2025¹⁹. In the first half of 2025 the solar share of total generation increased by 2.4 TWh while the combined wind and solar change was only a 0.4 TWh reduction¹⁹. Research by the Royal Society suggests the optimal solar and wind mix is 20/80²¹.

Demand is also shifting. Generation by Major Power Producers rose by 3.0% over September to November 2025 against the same period a year earlier², and nuclear generation was up 0.2% in the three months to May 2026⁷. For how that plays out at peak, see rising electricity demand and household demand flexibility.

What is being built: wind, solar and nuclear pipelines

Offshore wind is intended to carry most of the growth. It forms the backbone of the future system, in the words of the Climate Change Committee²²:

Government ambition is up to 50GW of offshore wind by 2030, including up to 5GW floating offshore wind²³, a target repeated as delivering up to 50 GW by 2030 alongside work on supply-chain bottlenecks including ports, vessel capacity and manufacturing capability²². An earlier commitment set 40GW in 2030 growing to 100GW or more by 2050²². The latest renewables auction in early 2026 secured 8.4GW of offshore wind overall²⁴. More detail sits on wind power on the UK grid.

Solar deployment has run ahead of older projections. Modelling in 2014 expected about 10 to 12 GWp of solar PV in the UK by the end of that decade, from 2.7 GWp then installed, and judged that 10 GWp of non-controllable solar PV in Great Britain could be accommodated without significantly changing operational practices²⁴. UK solar PV capacity reached 11,429 MW by November 2016²⁴, and the UK had 18 GW of solar in 2024²¹. Estimates assume up to 47 GW of installed solar PV capacity in Great Britain by 2030, supporting up to 20,000 direct jobs and up to 35,000 direct and indirect jobs²⁴. Seventh Carbon Budget modelling takes solar capacity to 82 GW by 2040²⁵.

The four nations do not look the same

Generation mix is a UK-level statistic that conceals four very different pictures. Scotland's renewable share of generation has long run above the rest of the UK: an official comparison gave 29.3% for the UK as a whole against 25.6% for the rest of the UK excluding Scotland²⁶, the gap being entirely Scottish hydro and wind. Scotland is legally committed to net zero greenhouse gas emissions by 2045. See energy supply in Scotland.

Wales has adopted a target to meet the equivalent of 100% of annual electricity consumption from renewable sources by 2035, alongside a target of at least 1.5 GW of renewable capacity being locally owned by 2035. Those are consumption-equivalence targets rather than hour-by-hour self-sufficiency: Welsh electricity still flows onto a shared transmission system. Energy supply in Wales covers this in detail.

Northern Ireland is the clearest exception. It is not part of the Great Britain market at all, sitting instead in the all-island Single Electricity Market with its own system operator and its own interconnection. Figures quoted for "GB" generation, including the solar records and the Smart Export Guarantee, do not apply there. See energy supply in Northern Ireland and the Moyle and East-West interconnectors.

Set against neighbours, the UK generates comparatively little per head: EU members produce on average almost 50% more electricity than the UK on a per capita basis²⁷. That is a statement about the size of the system, not its cleanliness, and part of the explanation is the UK's reliance on gas for heat rather than electricity in homes.

The rules that shape what is reported and what is built

Three sets of rules bear on the mix a household actually sees.

Fuel mix disclosure. All UK energy suppliers are required to publish information about their energy fuel mix annually²⁸. That is why a supplier's percentages exist at all, and why they cover a supply year rather than a calendar year. For renewable electricity generated overseas and supplied in Great Britain, qualifying renewable electricity must be generated in a Member State of the EU²⁹. A "100% renewable" tariff is therefore a contractual and certificate claim about a supply year, not a statement that renewable electrons reached a given meter.

Support for generation. The Smart Export Guarantee supports solar photovoltaics, wind, micro-combined heat and power, hydropower and anaerobic digestion up to 5 megawatts in capacity, or up to 50 kW for micro-CHP, and installations must be located in Great Britain³⁰. Larger low-carbon plant is funded through Contracts for Difference, with the closed Renewables Obligation still appearing on bills.

Levies and the price signal. An official expert group found that most of the regulated social and environmental levies are made on electricity rather than gas, increasing electricity's relative price, and that a rebalancing through action of the UK Government and Ofgem is urgently needed³¹. That policy choice sits between a cleaning grid and any household saving from it.

On safety, all UK electricity systems comply with the exposure limits in force in the UK for electromagnetic fields²⁸.

What the mix means for household energy independence

A cleaner grid is a national gain in energy security before it is a household one. Renewables have cut the UK's dependence on foreign fuels for electricity generation from 65% in 2014 to under 50% today, reported in 2025¹⁰, and solar is credited with reducing dependence on fossil fuel imports²⁰. Against that, the UK remains, on the Treasury's own description, "a net energy importer with a high dependence on gas and oil"³³.

Gas is the connection point between a household bill and a global market. Of UK gas demand in 2024, 26% was for electricity generation⁴, and in 2021 electricity generation took 29.8% of UK gas use¹¹. Because gas frequently sets the wholesale electricity price, a household on a fully renewable tariff still buys electricity priced in part by gas. That is the case even though offshore wind is reported as 60% cheaper than fossil fuels¹⁰. The mechanism is explained further in how the wholesale markets work and how global events move UK energy prices.

What a household can and cannot control is worth stating plainly:

• Cannot be changed by switching: the physical mix delivered to a meter, which is whatever the grid is running at that second.
• Can be chosen contractually: a tariff backed by UK-generated renewable electricity from independent producers, for example one supplier whose tariffs are described as powered by 100% renewable energy generated in the UK by independent producers²⁸.
• Can be reduced but not removed: grid dependence, through on-site generation and storage. Even a well-equipped home retains a connection, a supplier, standing charges and network charges.
• Remains external: fuel imports, interconnector flows, the capacity market and the balancing services that hold the system together.

The practical consequence of the daily swing is that timing matters more than the annual percentage. Where a home can shift load into the hours when wind and solar are plentiful, it uses a cleaner and often cheaper grid; where it cannot, it draws on the gas that is filling the gap. The UK grid is supplied by a mix of wind, nuclear, gas and solar³², and around half of UK electricity now comes from renewable sources³⁴, with over a third of Britain's electricity generated by wind, solar or hydro⁸ and over half from renewable energy sources on another 2026 assessment³⁴. Independence at household level is built from the storage, flexibility and generation a home controls, set against a grid mix it can read but not choose. For that side of the question, see energy security and household independence.