UK solar power generation hit a new high between June and August 2026, helped by long stretches of sunshine and continued growth in solar installations.
Solar farms and rooftop panels generated 8.8 terawatt-hours of electricity over the three-month period, according to Carbon Brief analysis. That was 23% higher than a year earlier and double the level recorded in 2021.
Clear skies were a major factor, according to Chris Hewett, chief executive of Solar Energy UK. Continued growth in solar installations also helped push generation higher.
The increase came during the UK’s hottest summer on record. Five heatwaves hit the country between May and August, with temperatures reaching 38.1C at Kew Gardens in London on August 13.
Britain recorded its sixth sunniest summer, while England and Wales had their second-sunniest. The Met Office said climate change made the record mean temperature 130 times more likely.
June, July and August all set new monthly highs for solar generation. July produced 3.3TWh, the highest amount generated in a single calendar month, with solar supplying 15% of UK electricity demand.
The growth in capacity has also played a role. Nearly 172,000 new installations have been fitted across the UK since the start of 2026, while domestic rooftop panels now account for around 29% of total generation.
By the end of August, solar generation for the year had reached 17TWh, up 13% from the same point in 2025. Extreme heat can reduce panel efficiency, but longer daylight hours and stronger sunshine more than offset those losses.
