UK households with rooftop solar generated enough electricity to power about 5 hours of daily whole-home air conditioning during the June 2026 heatwave, Ember said in a note on Wednesday.
A typical rooftop solar system produced enough electricity to run a 3-kilowatt air-conditioning setup for around five hours a day during the early stages of the heatwave, highlighting the link between solar generation and cooling demand, Ember said.
Solar output reached about 15 kilowatt-hours a day on June 21 and June 22, when the heatwave coincided with the summer solstice and boosted generation from household installations.
The UK Met Office issued Red Extreme Heat Warnings for parts of England and Wales on June 24 and June 25 after upgrading an Amber warning introduced on June 22. Forecasts showed temperatures exceeding 37 degrees Celsius.
As temperatures rise, nearly 22% of UK buildings may require active cooling in a 2-degree Celsius warming scenario, while English schools could face 70% more days with temperatures reaching 35 degrees Celsius, according to the Climate Change Committee's 2026 climate risk assessment.
During each day of the heatwave, Britain's 1.9 million solar-equipped homes produced enough electricity to support roughly 10 million hours of air-conditioning use. Growing battery adoption is also helping households use more of their solar generation throughout the day, Ember said.
Home battery installations doubled between 2024 and 2025, while households completed a record 253,500 rooftop solar installations in 2025. Installation activity during the first four months of 2026 ran 3% ahead of the same period last year.
Developers have secured contracts for 10,343 megawatts of additional solar capacity under the government's Contracts for Difference scheme, compared with 854 megawatts currently operating, according to Ember.
Expecting excess electricity supply during summer periods, the National Energy System Operator plans to use its Demand Flexibility Service to reward consumers for increasing power consumption when solar generation is abundant.
Subsidy programs helped Britain install 10 GW of solar capacity between 2012 and 2017 before deployment slowed sharply. Less than 2.5 GW was added during the following five years as support programs were phased out, Ember said.
Solar development has accelerated again despite the absence of household subsidies. Britain installed more than 2.5 GW of solar capacity in both 2024 and 2025, exceeding the total capacity added between 2017 and 2021.
Frequent record-breaking output signals that Britain has entered a second solar growth cycle. The country reset its half-hourly solar generation record 11 times in the first half of 2026, while output through June 21 ran 2% above 2025 levels after 2025 generation jumped 30% from 2024.
Solar production also exceeded 16 GW for the first time in 2026, more than 50% above levels recorded during the 2022 energy crisis, according to Ember.