Solar power generation in the UK reached a new record over the summer of 2026, as temperatures across the nation soared, according to new analysis by Carbon Brief.
Electricity generation from British solar installations reached an all-time high of 8.8 terawatt-hours during June, July, and August 2026, driven by record-breaking temperatures and expanded capacity, according to analysis by Carbon Brief. The historic output across Great Britain's solar farms and rooftops represents a 23% increase compared to the same period in 2025 and twice the volume produced during the summer of 2021.
The rise in generation coincided with Great Britain's warmest summer on record, which featured five separate heatwaves between May and August, as well as the sixth-sunniest summer nationally with over 620 hours of sunshine, Met Office figures show. Extended daylight hours and elevated solar radiation offset any reduction in panel efficiency caused by high heat. Regional weather records were also broken, including England's hottest June since 1884, its driest July since 1836, and a peak temperature of 38.1 degrees Celsius recorded at Kew Gardens on August 13. Met Office data indicates climate change made the summer's mean temperature record 130 times more probable.
Every summer month achieved new generation milestones, with July recording an all-time monthly high of 3.3 terawatt-hours, fulfilling 15% of total British electricity demand. Cumulative solar output for 2026 reached 17 terawatt-hours through August, marking a 13% rise year-over-year. Solar Energy UK Chief Executive Chris Hewett attributed the performance to sunny conditions and ongoing capacity additions, noting that the generation curtailed reliance on natural gas and stabilized broader power prices while lowering domestic energy expenses.
The grid's overall capacity expansion supported the output surge. Total installed capacity in Great Britain stands near 24 gigawatts according to University of Sheffield data, up from 21 gigawatts in the third quarter of 2025. Official statistics show approximately 172,000 systems have been added since the start of 2026, bringing total household installations to nearly 1.7 million, with residential setups comprising roughly 29% of nationwide capacity. Over 19,800 rooftop arrays were added in July alone. Analysis from Utility Bidder estimated that residential solar systems saved British households £86.7 million in power costs across 26 heatwave days during the period. Despite the seasonal totals, the half-hourly generation record remained at 15.2 megawatts, set on April 23, 2026.
Originally reported by Carbon Brief on Sep 4, 2026.
