As the UK experiences extreme temperatures, with forecasts above 37°C, think tank Ember finds that households with rooftop solar are powering the equivalent of five hours of air conditioning a day. Solar and air conditioning have similar seasonal patterns, meaning that when the need for cooling hits, solar is likely to be generating at a high level. On the 21st and 22nd of June 2026 a typical UK rooftop solar installation generated 15 MWh, equivalent to five hours of electricity demand from a full-house air conditioning set up (at 3 kW) per day. Across the 1.9 million UK homes with rooftop solar, the equivalent to 10 million solar-powered air conditioning hours have been generated each day of the heat wave so far. Although rooftop generation will be split across all household electricity use, this hints at the potential for cost-effective cooling in the future, particularly as home batteries become more common. “Air conditioning is becoming more urgent for households as the climate warms,” said the report author, Frankie Mayo. “As rooftop solar gets more and more popular to reign in energy bills and cut oil and gas use, this can complement the new need for cooling in British summers.” Rooftop solar installations boom in UK, hitting new generation records The UK’s need for household cooling is accelerating, as heatwaves become a fixture of British summers. At the same time, rooftop solar is experiencing a boom in the wake of the second energy crisis in four years. Homes are currently installing rooftop solar at the fastest ever annual rate. Over 2.5 GW of solar was installed in both 2024 and 2025, whereas 2.5 GW in total was installed in the five years from 2017 and 2021. This is happening without government subsidies for rooftop installations, unlike the UK’s first solar development boom from 2010-2016, which was supported by the now-closed Feed-in Tariff and Renewables Obligation subsidies. A large number of solar farms are also in development, supported by the government Contracts for Difference scheme. Although just 854 MW of solar is installed through the scheme so far, 10,343 MW is also contracted to be built before the early 2030s. This surge of installations has led to a huge increase in solar generation, with new records being broken frequently. The peak solar power half-hourly generation record was broken eleven times in the first half of 2026 alone. Britain also set a new all-time monthly solar generation record in May, beating the previous all-time record in May the previous year. Air con use in the summer can benefit the grid and consumers The UK grid can benefit from increased demand for air conditioning at high solar generation hours. A new service, the ‘Demand Flexibility Service’ is to be used to reward consumers for increasing electricity use during these periods. Even for households without rooftop solar, flexibility payments mean a wider pool of consumers can benefit by increasing demand during reward periods, including through the use of air conditioning. “More and more households are seeing the benefit of rising solar across the UK,” continued Frankie Mayo, “Plug-in balcony solar will make the technology more accessible, and at peak hours in the summer, households even without solar panels could be rewarded for using more electricity.” Read the full analysis. About Ember: Ember is an independent energy think tank that aims to accelerate the clean energy transition with data and policy. It creates targeted data insights to advance policies that urgently shift the world to a clean, electrified energy future.
