Renewable energy – considered crucial to limiting climate change – produced a record amount of electricity in Great Britain in 2025, BBC analysis shows.

Wind was the biggest single renewable source of electricity, according to the provisional figures from the National Energy System Operator (Neso).

But solar-powered electricity rose by nearly a third on 2024 levels, helped by the UK’s sunniest year on record and the expansion of solar panels around the country.

While behind renewables, electricity from fossil gas also rose slightly, highlighting the challenge of reaching the government’s “clean power” target by 2030.

“It has been quite a strong year in terms of deployment of renewables,” said Pranav Menon, research senior associate at the Aurora Energy Research think tank.

“[But] what we’re not seeing is kind of the exponential scale-up that you’d need to get to clean power 2030, because those targets are very, very ambitious,” he added.

Under its “clean power” target, the government aims to use hardly any polluting gas to produce electricity by 2030. It is also under pressure to meet its pledge to bring energy bills down by up to £300 by then and has argued that clean power can achieve this.

Neso data – and the clean power target – only cover Great Britain and not Northern Ireland, which has its own electricity transmission system operator.

The recent growth of renewables has been one of the strongest areas of progress in the world’s attempts to tackle climate change.

The trend has been notable in Great Britain over the past decade too. The government wants to ramp up renewables even more quickly to help meet its own clean power goal and reduce its planet-warming carbon emissions.

In 2025, wind, solar, hydro and biomass generated more than 127 terawatt hours (TWh) of electricity in Great Britain, according to BBC analysis of provisional Neso data.

That beats the previous high of 119TWh in 2024.

Wind generated more than 85TWh – nearly 30% – of Great Britain’s electricity last year, up slightly on 2024, according to analysis of Neso data.

But the most notable change was solar power.

Over the course of the year, solar panels generated more than 18TWh – over 6% of British electricity.

While that is still a relatively small share, it marks a growth of more than 4TWh versus 2024.

At its peak, solar was producing more than 40% of electricity for a small number of half-hour periods in July.

Back in 2013, no such period had more than roughly 5% of electricity generation from solar.

Part of the reason is the expansion of solar panels across the UK. More large solar farms came online this year, including the biggest at Cleve Hill near Faversham, in Kent.

And it was a record year for solar panels on rooftops, with about 250,000 new small-scale installations reported to the Microgeneration Certification Scheme.

With 2025 the UK’s sunniest year on record, conditions were ideal for British solar panels to capitalise on long, sunny days through the spring and summer.

“Solar’s probably a bigger part of the system than we’d expected, given the cost has come down so much,” said Michael Grubb, professor of energy and climate change at University College London.

Renewables can generate significant amounts of electricity when conditions are right. On roughly a third of days in 2025, at least half of Britain’s electricity came from renewables, according to BBC analysis of Neso data.

But the British electricity grid often still leans heavily on fossil fuel gas.

Analysis of Neso’s figures shows gas generated more than 77TWh – roughly 27% – of electricity, up from 72TWh in 2024.

That increase could be down to several factors, including Britain importing slightly less electricity from Europe, lower nuclear generation, the closure of the last coal power station in 2024 and higher electricity demand.

Driven by the rise in gas, Britain’s electricity was slightly more polluting in 2025 than 2024, according to Neso’s data.

In 2025, each kilowatt-hour (kWh) of electricity generated 126g of planet-warming carbon dioxide on average – up from 124g/kWh in 2024 but down from 505g/kWh in 2012.

With the exception of wind and solar, Neso’s figures only cover generation connected to the main transmission network.

They do not include smaller-scale gas, biomass and hydro operators feeding in electricity at a local level, but these contribute a relatively small fraction of Britain’s total generation.

Separate analysis of UK government data by the climate website Carbon Brief – which includes these smaller sources and Northern Ireland – shows very similar trends to the Neso data for Great Britain. That includes a new renewables record and a slight rise in gas generation.

The government has defined its “clean power” target as 95% of all electricity generated in Britain coming from renewables and nuclear energy by 2030.

In 2024 clean sources produced almost three-quarters of total electricity generation for the year, according to government figures.

These numbers differ from Neso data, which includes imports as well as some gas generation not covered by the government’s clean power definition.

Government figures for 2025 will not be released until later this year – but the amount of gas still in the electricity mix shows there is much to be done.

“There’s still a significant number of periods in the year where the sun’s not shining, the wind’s not blowing, demand is high […] and that’s where the system is sort of forced to rely on gas-fired power to turn up and meet demand,” said Mr Menon.

He added that there were solutions to this challenge. They include technologies like batteries – to store renewable electricity to use when it is less sunny and windy – as well as other low-carbon sources like nuclear, which can provide dependable output.

One of the other struggles in meeting the clean power target is the need to upgrade the electricity grid, partly to connect new renewables and move their electricity around the country.

Sometimes the grid cannot cope with all of the renewable electricity that could be generated, leading to wind farms being paid to reduce their output.

Grid upgrades should help to reduce the problem but upgrades add to costs in the short term.

That could offset some of the savings from some of the cheapest renewables which are starting to displace gas power, according to Prof Grubb.

But he said he still expected bills to start to come down in the coming years – partly due to those renewables, but also assuming gas prices fall from their recent high levels.

In response to the renewables data, Energy Secretary Ed Miliband said: “After years of delay and underinvestment, this government is keeping its promise to take back control of Britain’s energy with clean homegrown power.”

This would “protect households against volatile fossil fuel markets”, he added.

But shadow energy secretary Claire Coutinho called on the government to ditch its clean power target, arguing it was raising energy bills.

“Britain is generating more renewable power than ever before, but people should know about the extra costs that come along with it,” she said.