Analysis: UK solar power hits record high over summer 2026

Summer 2026 was the sixth sunniest on record, with more than 620 hours of sunshine, according to the Met Office. Domestic rooftop solar accounts for around 29% of total capacity. In 2025, the UK’s solar capacity reached 21 gigawatts (GW) , according to UK government figures. This is a jump of 3GW, or 18%, year-on-year, as Carbon Brief reported in January.  (Capacity is the maximum output possible from an electricity generation, whereas generation is what was produced over a certain time period, such as a day, month or year.) According to the University of Sheffield, the installed solar capacity is now nearly 24GW.  This includes nearly 172,000 solar installations that have been fitted across the UK since the start of 2026, according to recent government figures. In July alone, more than 19,800 rooftop solar panels were installed – the equivalent of one installation every two minutes.  In total, nearly 1.7m households in the UK now have solar panels installed.  Over 26 heatwave days this summer – periods of at least three days when temperatures exceed the Met Office’s county-level heatwave temperature threshold – UK households with rooftop solar panels avoided an estimated £86.7m in electricity costs, according to analysis . Talking about the surge in solar generation this summer, Hewett says:  “[It] not only kept bills down for people with solar and batteries in their homes, but helped keep overall power prices much lower than they would have been if Britain had been relying on more gas generation during the day”. Despite the record generation, no new half-hourly solar power output record was set in the summer of 2026. This still stands at 15.2 megawatts (MW) on . * This article refers to the UK throughout, but strictly relates to the island of Great Britain, made up of England, Scotland and Wales. Northern Ireland is part of the separate, all-Ireland electricity system. Factcheck: 10 flaws in the Conservative report on ‘cheap power’ 20.08.2026 Renewables Q&A: What is ‘long-duration energy storage’ – and why does the UK need it? 19.08.2026 Electricity Q&A: What does China’s 15th ‘five-year plan’ for renewables mean for climate change? 29.07.2026 China policy Analysis: Wind and solar power overtake fossil fuels in Germany for first time ever 28.07.2026 Energy