Solar power in the UK has achieved a significant milestone by supplying more than 10% of the nation's electricity for two consecutive months—April and May 2025. This breakthrough reflects a combination of record-breaking solar generation capacity, unusually sunny weather, and strong government and industry support for solar expansion, marking a pivotal moment in the country’s clean energy transition.
Record Solar Generation in Spring 2025
In April and May 2025, solar power accounted for over 10% of the UK’s electricity supply for the first time ever in back-to-back months, reaching 11.6% in May. This milestone was driven by an extraordinary surge in solar output, representing a 42% year-on-year increase compared to the same period in 2024. solar farms and rooftop installations generated a record 7.6 terawatt-hours (TWh) of electricity from January to May 2025, up from 5.4 TWh the previous year and a 260% increase over the past decade.
April and May proved particularly exceptional, with solar generation in May hitting a new monthly high of 2.5 TWh, surpassing April’s 2.3 TWh. Average electricity output from solar installations reached 3,189 megawatts (MW) in April and 3,383 MW in May, both significantly higher figures than those recorded in previous years.
The Role of Sunniest Spring on Record
A key factor behind this solar boom was the sunniest spring on record since 1910, as reported by the UK Met Office. Between March 1 and May 31, 2025, the UK experienced 653 hours of sunshine—43% more than the 1961–1990 average for the same months. This abundance of sunshine, combined with long daylight hours, and rising solar capacity, propelled solar power generation to unprecedented levels. The spring of 2025 was not only the sunniest spring but also the fourth-sunniest season ever recorded in the UK.
Growing Solar Capacity Boosts Output
While excellent weather was crucial, the surge in solar output was also strongly supported by continued growth in installed solar capacity. By the end of 2024, UK solar capacity had reached 20.2 GW, up 2.3 GW from 17.9 GW the year before. This extra capacity has enabled a greater share of the electricity mix to come from solar, complementing the weather-driven boost.
Looking ahead, the UK government has set ambitious targets to more than double solar capacity to at least 45 GW by 2030, as part of its Clean Power 2030 plan and net-zero 2050 goals. Large-scale solar farms with capacities of 500 MW or more are being approved and developed, alongside widespread rooftop solar deployment on residential and commercial buildings.
Impact on Energy Security and Emissions
This surge in solar generation has tangible benefits for the UK’s energy security and climate commitments. Solar electricity generated in 2025 to date has displaced the need for around £600 million worth of gas imports, avoiding approximately 6 million tonnes of CO2 emissions that would have resulted from burning that gas. By reducing reliance on imported fossil fuels, solar supports both environmental goals and stabilises energy costs for consumers in a volatile global energy market.
Setting New Records for Instantaneous Solar Output
In addition to monthly milestones, solar power set new instantaneous generation records. On 6 April 2025, at 1 p.m., solar output reached 13.2 GW—enough to meet about 40% of the UK’s electricity demand at that moment. Earlier in the year, on 1 April, a record 12.2 GW output was recorded, showcasing the rapid rise in solar generation capability across Great Britain.
Challenges and the Path Forward
Despite this rapid growth, challenges remain in expanding solar further. Grid connection delays, planning bottlenecks, and supply chain pressures still affect the pace of new installations. Addressing these issues through government reforms and industry collaboration is critical to sustaining momentum.
The UK’s robust public support for solar and renewables overall continues to drive demand. Solar energy is recognized for its declining costs, quick installation times, and significant environmental benefits. These factors combine to position solar as a cornerstone technology in the UK’s clean energy future.
Conclusion
The unprecedented achievement of solar supplying over 10% of the UK’s electricity for two consecutive months in 2025 signals a transformative shift in the energy landscape. Fueled by record sunshine and expanding capacity, solar power is not only proving its viability as a major electricity source but also delivering substantial economic and environmental benefits.
With strong policy support, continued technological advancements, and ongoing growth in installations, solar energy is on track to play a central role in reaching the UK’s 2030 climate ambitions and its ambitious net-zero 2050 target.
