A record year for British solar

In the first half of 2025, record-breaking solar generation in Great Britain offset lower-than-average wind speeds, limiting the increase of gas power. Solar generation rose by 32% to 9.91 TWh, with a peak grid level of 14 GW on 8 July. Analysis shows that low-wind and low-solar days coincide only 2% of the time, demonstrating a natural balance in the British climate. While gas generation increased overall in H1 2025 to compensate for lower power imports, it fell to 21% of electricity generation in June. The report advocates for doubling energy storage capacity by 2030 and transitioning gas and biomass plants to a strategic reserve by the early 2030s to further reduce costs and emissions.

• Solar power in Great Britain achieved record-breaking generation in the first half of 2025, increasing by 32% to reach 9.91 TWh and breaking generation records for five consecutive months starting in March. A peak of 14 GW was recorded on the grid on 8 July, which is 44% higher than the 2020 peak of 9.7 GW.
• Wind and solar power are highly complementary in the British climate; analysis of data from January 2017 to June 2025 shows that days with both low wind and low solar generation (below the 20th percentile for both) occur only 2% of the time.
• In the first half of 2025, solar generation increased by 2.4 TWh, which helped offset a 2.8 TWh reduction in wind generation. Despite this, overall gas generation in the first half of the year was 5.7 TWh higher than in the first half of 2024, primarily to fill a 3 TWh gap caused by falling power imports from Europe.
• Gas power reached record lows in May and June 2025, falling to 21% of electricity generation in June, displaced by strong wind and solar performance.
• Domestic solar installations are increasing in size, with the 4-10 kW band growing from 5% of capacity installed below 10 kW in 2015 to 50% in 2025. Additionally, the 'Future Homes Standard' will require new homes to have solar panels 'by default' before the end of 2025.

APA

Mayo, F. (2025). A record year for British solar. Ember. https://ember-energy.org/app/uploads/2025/08/a-record-year-for-british-solar-analysis-1.pdf

Chicago

Mayo, Frankie. A record year for British solar. Ember, 2025. https://ember-energy.org/app/uploads/2025/08/a-record-year-for-british-solar-analysis-1.pdf.

Wikipedia

{{cite report |last1=Mayo |first1=Frankie |title=A record year for British solar |publisher=Ember |date=28 August 2025 |url=https://ember-energy.org/app/uploads/2025/08/a-record-year-for-british-solar-analysis-1.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{mayo2025record, author = {Mayo, Frankie}, title = {{A record year for British solar}}, institution = {Ember}, year = {2025}, month = aug, url = {https://ember-energy.org/app/uploads/2025/08/a-record-year-for-british-solar-analysis-1.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }