Solar Power in UK Surges 42% With Sunniest Spring on Record: Analysis

Solar farms and rooftops in the United Kingdom generated a record 42 percent more electricity from January through May 2025 than during the same period in 2024, according to a new analysis by Carbon Brief.

The UK also just had its sunniest spring since record keeping began in 1910, the Met Office said.

Data from the National Energy System Operator shows that solar sites in the UK generated 7.6 terawatt hours (TWh) of electricity in the first five months of 2025. That’s 42 percent more than the 5.41 TWh generated last year at the same time. It also marks a 260 percent increase over the past decade.

“Solar power is rising faster than most people realise. It is cheap, fast to install and every unit of electricity it generates here in the UK displaces two units of imported gas,” said Simon Evans, senior policy editor at Carbon Brief, as The Times reported.

NEW ANALYSIS: UK's solar power surges 42% to a new record, after the sunniest spring on record * For the first time, solar was >10% of UK generation in consecutive months (April/May 2025) * In 2025, solar has already avoided gas imports that would've cost £600m www.carbonbrief.org/analysis-uks…

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— Simon Evans (@drsimevans.carbonbrief.org) June 4, 2025 at 11:41 AM

Solar in the UK also reached a new half-hourly milestone at 1 p.m. on April 6, generating a record 13.2 gigawatts (GW) and meeting 40 percent of electricity demand, Carbon Brief said.

For the first time, solar made up over 10 percent of monthly electricity generation two months in a row — April and May. Solar accounted for 11.6 percent of the UK’s electricity generation in May, just the fourth time the 10 percent threshold has been breached.

So far, this year’s solar electricity output in the UK has avoided gas imports of roughly $813.9 million, which would have released approximately 6.61 million tons of carbon dioxide.

Though this year’s solar record was driven partially by the sunniest spring on record, rising capacity also helped. The UK’s solar capacity is on track to reach a minimum of 45 GW by the end of the decade, as part of the country’s goal of decarbonizing the power sector and becoming a “clean-energy superpower.”

UK solar installations generated an average of 2,320 megawatts (MW) of electricity in March, up 66 percent from 2024. April saw a jump of 53 percent from the previous year.

Electricity from solar also reached a high of 2.5 TWh in May, with April in second place with 2.3 TWh.

Between March 1 and May 31 of this year, the UK had 653 hours of sunshine — 43 percent higher than average for the period 1961 to 1990.

Sunshine hours in the UK have been increasing, especially since the 1980s, with spring months an average of 15 percent sunnier during the past decade, the analysis found.

This spring was not just the sunniest spring, but the fourth-sunniest season on record, with only three summers topping its sunshine hours. The abundance of sunshine, along with growing capacity, contributed to the unusually high output of solar power.

After stagnating for several years, installed solar capacity in the UK had jumped to 20.2 GW by the end of 2024. As capacity has grown, prices have fallen, increasing solar’s economic benefits.

Roughly 3 GW of new capacity have been approved for gigantic sites, including the Heckington Fen and Gate Burton solar farms, each with the potential to produce 500 MW of electricity once installed.

“Every new solar panel installed in the UK makes us less dependent on gas imports, which is good for our energy independence as well as for stabilising energy bills given the sun offers up its power for free,” said Jess Ralston, Energy and Climate Intelligence Unit analyst, as Business Green reported. “As we install more solar and build more wind turbines, our reliance on gas will fall.”