Renewable electricity generation in Britain reached a record high in the third quarter of 2025, driven by strong performance from wind and solar sources, according to data released by Montel Analytics on Monday.
Total renewable generation, including biomass, reached 31.9 terawatt hours (TWh) between July and September — the highest Q3 figure since records began in 2014.
Wind power led the increase, generating 17.7TWh during the quarter, up 6% from 16.7TWh in the same period last year. Montel said the rise came despite curtailments in September, when strong wind conditions coincided with low demand and negative power prices.
Solar output also rose sharply to 6.2TWh — the second-highest quarterly figure on record — boosted by extended periods of sunshine during summer heatwaves in July and August.
“High levels of renewable generation are symptomatic of a long-term commitment to produce more of our power from clean sources,” said Phil Hewitt, director at Montel Analytics. “Wind output would have been even higher had it not been for several curtailments across the quarter.”
The growth in renewables contributed to a reduction in fossil fuel usage. Gas-fired electricity generation fell to 15.4TWh, a 25% drop from 20.5TWh in the third quarter of 2023. Nuclear output declined to 7.8TWh — its lowest third-quarter level in over a decade — due to maintenance work at several plants.
In total, renewable energy accounted for 51% of Britain’s electricity supply during the quarter. Gas contributed 24%, imports 13%, and nuclear 12%, according to the data.
Looking ahead, Hewitt noted that electricity prices were expected to remain stable into the fourth quarter, barring any significant geopolitical disruptions. “Forecasts suggest the possibility of below-normal temperatures occurring during the winter months, driven by emerging La Niña conditions,” he said. “This could increase demand and accelerate storage drawdowns, adding upward pressure on wholesale electricity prices.”
The findings come as the UK continues its transition toward cleaner energy sources, amid ongoing volatility in global gas markets and increasing policy focus on energy security.
