Solar Energy UK
17 December 2025
A record 6.3% of Great Britain’s power was supplied by the sun in 2025, according to official figures. The extraordinary 30% rise in generation follows the sector smashing several other records this year.[1]
As of yesterday, an estimated 18,314 gigawatt-hours of sun-powered electricity was generated over the year. That’s enough to make over 732 billion cups of tea or keep around 4.6m typical three-bed semi-detached homes warm using a heat pump for a year.
A total of 14,067GWh came from solar energy in 2024, according to grid operator NESO.
The sector is already making a significant contribution to reducing the cost of electricity from the grid. With further growth and reform to the electricity market, this will be more apparent over the coming years.
Solar energy’s growth contributed to Great Britain’s electricity supplies having their second lowest carbon intensity ever this year, averaging only 126 grams of CO2 per kilowatt-hour, down from 444g/CO2 in 2009.
The massive jump was largely, though not exclusively, due to an 18% surge in capacity over the year, going from about 20.2 gigawatts to around 23.8GW by the end of the year, according to estimates from Solar Media’s Market Research Analyst Josh Cornes. Around 650MW is expected at the smaller scale (largely on residential rooftops), 450MW on the roofs of commercial buildings and 2.5GW on the ground as solar farms.
The record-breaking weather this year also played a significant role. As of Monday, the UK recorded 1,622 hours of sunshine over the year, more than any year since Met Office records began in 1910.[2] Scotland saw its second sunniest year, Wales its sixth, while Northern Ireland was well above the long-term average.
The previous UK record had stood since 2003. March and April were the sunniest, while May was the second sunniest, seeing 653 hours of sunshine in all – 43% above average.[3] The summer was also bright, with 556 hours of sunshine over June, July and August, or 10% above the long-term average. [4] Southern and eastern England, where solar farms are more concentrated, were particularly sunny.
In contrast, the pattern of sunny and dry weather broke in the Autumn, though September still had slightly above-average hours of sunshine.
Energy Minister Michael Shanks said: “Solar is one of the cheapest forms of power – getting us off fossil fuels and delivering energy security so we can get bills down for good. The sunniest year on record highlights the huge opportunity we have to make the most of this clean energy source and keep installing more solar panels on schools, hospitals and homes.
“As we move into 2026, we will scale up the solar power we need to shield households from volatile fossil fuel markets and tackle the climate crisis,” he added.
Chris Hewett, Chief Executive of Solar Energy UK, said: “The solar sector has long passed being a bit-player in the UK energy market. It is now supplying six times more hydropower, more than half of the output from nuclear and a quarter of the power generated from natural gas. With capacity set to rise to almost 60GW over the coming decade, we are guaranteed to see records tumble each year, putting the nation on course for cheaper, cleaner power.”
Professor Alaistair Buckley of the University of Sheffield, the UK’s foremost solar academic and responsible for estimating Great Britain’s photovoltaic output, said: “Solar has truly come of age, with a strong subsidy free market. Together with co-located battery storage, it makes for a powerful combination that will help drive the national energy system. The UK is on track to meet its projected photovoltaic capacity under the Clean Energy plan and these latest numbers support that.”[5]
More records broken
2025 broke many records, reflecting how solar energy has become the cheapest source of power for the UK.
Earlier in the year, Cleve Hill solar farm in northern Kent came online. At 373MW, it is by far the largest of its kind in the UK.[6] The next greatest is Llanwern near Newport, at 75MW.
The number of smaller-scale solar rooftop installations smashed the annual record of 203,125 that had stood since 2011.[7] Almost 250,000 have been reported to standards body MCS, with data still coming in.[8] Much of the increase can be attributed to the newbuild market, with new homes often coming with solar panels pre-installed. The forthcoming Future Homes Standard and Future Buildings standard will make this all but mandatory for new construction.
March and October had the fifth and sixth most installations recorded by MCS since the scheme began in 2009.
A new record for the most instantaneous solar power generated was set at 12.30pm on 8 July, reaching just over 14GW, of 43% of demand. The previous record of 13.8GW had been set on 6 April.[9]
Meanwhile, the sector has continued to innovate. Associated British Ports will deploy 40MW at the Port of Barrow, after Westmorland & Furness Council approved the project in November.[10] In conjunction with Solar Energy UK members, Peel Ports is working on the largest rooftop installation, at the Port of Liverpool. A total of 31MW will be deployed there next year, five times more than the current record holder at the Port of Hull.[11,12]
[1] Historic GB Generation Mix – NESO
[2] 2025 is already the UK’s sunniest year on record – Met Office
[3] Spring 2025 – Met Office
[4] Summer 2025: A regional breakdown – Met Office
[5] PV Live – University of Sheffield
[7] UK rooftop solar installations hit record high – MCS
[8] MCS Data Dashboard – MCS
[9] British and French solar generation hit new records – Solar Energy UK
[10] Approval granted for UK’s largest floating solar energy project at Port of Barrow – Associated British Ports
[11] Record-breaking rooftop solar project welcomed by Solar Energy UK
[12] Case Study – Port of Hull – Solar Energy UK
– ENDS –
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