Record year for wind and solar electricity in Great Britain in 2025

Great Britain witnessed an unprecedented surge in renewable energy generation in 2025, with wind and solar power reaching record highs, according to comprehensive analysis by the BBC of provisional figures from the National Energy System Operator (Neso). This landmark achievement underscores the nation’s accelerating transition towards a greener energy mix, a critical step in mitigating climate change and meeting ambitious decarbonisation targets. However, the data also highlights persistent challenges, as electricity from fossil gas saw a modest increase, tempering the celebrations and underscoring the complexities of achieving the government’s "clean power" target by 2030.

The year 2025 emerged as a pivotal moment for renewable energy, with wind, solar, hydro, and biomass collectively generating over 127 terawatt hours (TWh) of electricity across Great Britain. This figure comfortably surpassed the previous record of 119 TWh set in 2024, demonstrating a significant upward trajectory in the deployment and output of clean energy sources. The sustained growth of renewables has been a global phenomenon, representing one of the most promising areas of progress in the fight against climate change, and Great Britain has actively participated in this trend over the past decade. The government’s strategy to ramp up renewable capacity is driven by dual objectives: to meet its stringent clean power goals and to drastically reduce planet-warming carbon emissions.

While the overall picture for renewables was overwhelmingly positive, the individual contributions painted a dynamic landscape. Wind power continued to be the bedrock of Great Britain’s renewable electricity supply, generating more than 85 TWh, accounting for nearly 30% of the nation’s total electricity last year. This marked a slight but steady increase from 2024, reflecting ongoing investments in both onshore and vast offshore wind farms that harness the UK’s abundant wind resources. These colossal turbines, particularly those situated off the coast, are increasingly becoming a familiar sight, symbolising the nation’s commitment to harnessing natural elements for power.

However, the most striking narrative of 2025 belonged to solar power. Over the course of the year, solar panels, from sprawling utility-scale farms to countless rooftop installations, generated over 18 TWh, contributing more than 6% of British electricity. While still a smaller share compared to wind, this represented an impressive growth of more than 4 TWh compared to 2024 – a nearly one-third increase. This remarkable leap was significantly bolstered by two key factors: the expansion of solar infrastructure and, serendipitously, the UK experiencing its sunniest year on record. Extended periods of clear skies and strong sunshine, particularly through the crucial spring and summer months, provided ideal conditions for solar arrays to operate at peak efficiency. This meteorological good fortune allowed solar to achieve unprecedented output, with the technology producing over 40% of electricity for certain half-hour periods in July, a stark contrast to the mere 5% seen in similar periods back in 2013.

The expansion of solar capacity was driven by both large-scale projects and widespread domestic adoption. Several new large solar farms came online, notably the immense Cleve Hill site near Faversham in Kent, which significantly boosted the grid’s solar intake. Concurrently, the uptake of rooftop solar panels by homeowners reached an all-time high, with approximately 250,000 new small-scale installations reported to the Microgeneration Certification Scheme. This widespread adoption reflects not only growing environmental awareness but also the increasing affordability of solar technology and the appeal of reducing household energy bills. As Professor Michael Grubb, an expert in energy and climate change at University College London, noted, "Solar’s probably a bigger part of the system than we’d expected, given the cost has come down so much," highlighting the technology’s unexpected yet welcome acceleration.

The growing dominance of renewables meant that Great Britain’s electricity grid was often powered predominantly by clean sources. On roughly a third of days in 2025, at least half of the nation’s electricity came from renewables, a testament to the transformative changes underway. These days, often characterised by strong winds or abundant sunshine, offered a glimpse into a future where fossil fuels play a diminished role.

Despite these impressive strides, the continued reliance on fossil fuel gas remains a critical hurdle. Analysis of Neso’s figures reveals that gas-fired power stations generated over 77 TWh of electricity in 2025, accounting for approximately 27% of the total, a notable increase from 72 TWh in 2024. This uptick in gas generation, even amidst record renewable output, can be attributed to a confluence of factors. These include a slight reduction in electricity imports from European interconnectors, potentially due to maintenance, market dynamics, or demand fluctuations on the continent. Furthermore, lower nuclear generation, a consequence of an aging fleet and scheduled maintenance outages, necessitated a greater reliance on gas to fill the gap. The closure of the UK’s last coal power station in 2024, while a significant environmental milestone, also meant that gas often stepped in as the primary flexible power source. Lastly, an overall increase in electricity demand, possibly driven by economic activity or early electrification efforts in heat and transport, also contributed to the higher gas consumption.

Consequently, the carbon intensity of Great Britain’s electricity supply saw a slight increase in 2025, rising to an average of 126 grams of planet-warming carbon dioxide per kilowatt-hour (kWh), up from 124g/kWh in 2024. While this slight increase is a concern, it is crucial to contextualise it against the dramatic long-term progress: the average carbon intensity has plummeted from a staggering 505g/kWh in 2012, showcasing the profound decarbonisation achieved over the past decade.

The government’s ambitious "clean power" target aims for 95% of all electricity generated in Britain to come from renewables and nuclear energy by 2030. While government figures for 2024 indicated that clean sources produced almost three-quarters of total electricity, the recent Neso data, particularly the rise in gas generation, signals that the path to 2030 is fraught with challenges. The Neso data, which includes certain imports and does not always align precisely with the government’s "clean power" definition for gas, provides a clearer picture of the operational grid.

Pranav Menon, a research senior associate at Aurora Energy Research, highlighted the core issue: "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 further elaborated on the inherent variability of renewables, stating, "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."

Addressing this intermittency is paramount. Solutions include a significant build-out of energy storage technologies, particularly large-scale batteries, which can store surplus renewable electricity generated during peak production times and release it when demand is high or renewable output is low. Furthermore, other low-carbon sources, such as new nuclear power stations like Sizewell C and potential extensions to the operational lives of existing nuclear plants, are crucial for providing a stable, baseload power supply. Advanced technologies like carbon capture and storage (CCS) for gas plants are also being explored to decarbonise a portion of the fossil fuel generation that may remain necessary for grid stability.

Another significant hurdle in meeting the clean power target is the urgent need to upgrade Great Britain’s electricity grid. The existing infrastructure was not designed for a decentralised, intermittent, and geographically diverse energy system. Connecting new, often remotely located renewable projects, particularly vast offshore wind farms, and efficiently transporting their electricity across the country requires substantial investment and complex engineering. Grid constraints can lead to situations where wind farms are paradoxically paid to reduce their output, or "curtailment," because the network cannot handle the full volume of renewable electricity. While grid upgrades are underway and should alleviate these issues in the long term, they represent significant short-term costs that can add to energy bills, potentially offsetting some of the immediate savings derived from cheaper renewable generation, as Professor Grubb pointed out. However, he maintained optimism that overall energy bills would likely decrease in the coming years, driven by the increasing deployment of cost-effective renewables and an anticipated stabilisation of global gas prices from their recent volatile highs.

The record-breaking year for renewables in 2025 naturally sparked political debate. Energy Secretary Ed Miliband hailed the achievements, stating, "After years of delay and underinvestment, this government is keeping its promise to take back control of Britain’s energy with clean homegrown power." He emphasised that this strategic shift would "protect households against volatile fossil fuel markets," underscoring the government’s narrative of energy security and economic stability through domestic clean energy.

Conversely, Shadow Energy Secretary Claire Coutinho adopted a more critical stance, urging the government to reconsider its clean power target, arguing that it was contributing to rising 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 commented, highlighting concerns over the financial implications of the energy transition and the burden on consumers.

The 2025 data paints a clear picture: Great Britain is making substantial progress in its renewable energy journey, with wind and solar leading the charge to new heights. Yet, the persistent role of fossil gas and the inherent challenges of grid modernisation and intermittency mean that the path to a fully decarbonised, clean power system by 2030 remains an ambitious and complex undertaking, requiring sustained investment, innovation, and political will.