According to the latest report from Ember, solar power generation reached a record 9.91 TWh in the first half of 2025.
The clean energy think tank Ember’s latest report indicates that 2025 has become the strongest year on record for solar power generation in the UK. In the first six months of the year, solar generation increased by 32% year-on-year, reaching a record 9.91 TWh.
UK Solar Power Generation Surges 32% in First Half of 2025
Since the beginning of 2025, solar power generation has consistently broken records, setting new monthly peaks for five consecutive months starting from March. On July 8, a new all-time high for instantaneous solar power supply to the UK grid was achieved—14 GW of solar power supplied simultaneously nationwide, marking a 44% increase compared to the annual peaks of the past five years.
This surge in generation is largely attributed to two key factors: record-breaking sunshine hours this summer and a significant increase in solar photovoltaic (PV) capacity. Josh Cornes, a market research analyst at Solar Media, pointed out that in the first half of 2025, the UK added over 2 GW of new solar PV capacity—nearly matching the total installations for the entire year of 2024, making it the strongest start to a year in a decade. The UK’s total operational solar PV capacity has now exceeded a peak of 22 GW.
Residential solar installations have also seen an upward trend. Data from Ember shows that residential PV installations have reached their highest level in a decade. Figures released this month by the Microgeneration Certification Scheme (MCS), a certification body for low-carbon technologies, confirm that certified component installations across the UK reached 120,000 in the first half of 2025, a 37% year-on-year increase, breaking the previous record set in the first half of 2012.
Ember attributes the rise in residential solar adoption to two main drivers: a 10% year-on-year increase in energy prices (equivalent to £152) and a decline in installation costs. MCS data shows that the average cost per kilowatt for residential solar PV has continued to decrease since the summer of 2023, falling from £2,009/kW in 2023 to £1,590/kW this year.
The think tank also noted that the average size of residential solar installations has significantly increased since the feed-in tariff scheme (which offered higher rates for systems under 4 kW) ended in 2019. Over the past decade, the share of 4-10 kW systems has grown tenfold, rising from 5% in 2015 to 50% this year.
Wind and Solar Complement Each Other
The report also emphasized that the UK’s renewable energy mix, combining wind and solar power, effectively balances the fluctuations in energy demand caused by the country’s variable climate. While the number of high-sunshine days increased significantly in the first half of 2025, wind power generation declined—a stark contrast to the situation in early 2024.
According to Ember’s calculations, days with both low sunshine and low wind power accounted for only 2% of the recent period, contributing to a record-low 21% share of natural gas in the grid this June.
