Wind and solar power drive UK renewable electricity record

Britain’s renewable electricity generation hit a new record for the third quarter of 2025, with wind and solar production combining to provide the country’s cleanest energy mix ever, according to the latest data from Montel Analytics.

In the three months to the end of September, total renewable energy production – including wind, solar, hydro and biomass – reached 31.9 terawatt-hours, the highest third-quarter figure since records began in 2014. Renewables accounted for 51% of total power generation in Britain, surpassing all fossil fuel sources combined.

Wind power led the charge at 17.7 TWh, up 6% year-over-year and the highest third-quarter production Monttel has ever recorded. This increase came despite multiple curtailment periods, particularly in September when strong winds coincided with weak demand, pushing electricity prices into negative territory for several hours.

Solar power generation also saw exceptional gains, producing 6.2 TWh – the second-highest quarterly total since records began, behind only Q2 2025. This represents a 32% increase over the Q3 2024 total of 4.7 TWh, fueled by prolonged sunshine and intense summer heat waves in early July and mid-August that led to a Temperatures and boosting cooling demand across the UK.

Phil Hewitt, director of Montel Analytics, said these figures reflect Britain’s accelerating shift towards renewable energy and the growing impact of clean generation on the overall energy mix.

“High levels of renewable energy generation are a symptom of a long-term commitment to producing more energy from clean sources,” Hewitt said. “Wind production would have been even higher had it not been for several reductions during the quarter. Due to high levels of renewable generation, gas-fired power requirements were significantly reduced.”

The boom in renewables continues to replace gas-fired power. Combined cycle gas turbine (CCGT) plants produced 15.4 TWh in the third quarter – up slightly from the record low of 13.8 TWh the year before, but still 25% below 2023 levels, when total gas generation reached 20.5 TWh.

Meanwhile, the UK’s nuclear fleet production fell to 7.8 TWh, its lowest level in the third quarter since 2014. Multiple reactors, including Hartlepool 2, Heysham 1 and 2, and Torrens 1 and 2, were out of service for maintenance and refueling during the period.

As a result, renewables dominated Britain’s energy mix in the third quarter (51%), followed by gas (24%), imports (13%) and nuclear (12%).

Hewitt noted that the rising share of renewable energy, coupled with lower summer demand, helped stabilize wholesale energy prices during the third quarter.

“The quarter followed the expected seasonal trend, with warm weather easing demand on the system and contributing to lower gas and electricity prices than we saw in the second quarter,” he said. “We expect stability to continue in the fourth quarter, unless geopolitical tensions – particularly in the Middle East – lead to higher gas prices.”

Gas storage levels across Europe are now almost full ahead of winter, but analysts warn that emerging La Niña conditions could lead to colder than usual weather in the UK and northern Europe later in the year.

“La Niña typically occurs every three to five years and can lead to colder winters,” Hewitt said. “This could increase demand, accelerate inventory withdrawals, and add upward pressure on wholesale prices. However, this appears to be a weak La Niña event that may fade away.”

New data underscores the resilience and importance of renewables in the UK’s energy system – even in the face of market volatility and infrastructure constraints.

Analysts said this record quarter strengthens the UK’s position as a global leader in clean energy generation, while also highlighting the need for greater grid and storage flexibility to prevent curtailments during periods of high production.

As the UK heads into the winter months, the balance between renewable energy generation, system demand, and gas market stability will be crucial to maintaining energy security – and maintaining the downward trend in wholesale prices that consumers and businesses hope will continue.