Britain's Electricity Generation - August 2025
Fuel Type Breakdown
Britain’s electricity generation in August 2025 was led by wind, which supplied 26% of the mix. While this marked a strong showing, it was notably down from 32% in August 2024. Despite the decline, it represented the second-highest August wind share in the past five years, underscoring the technology’s continued importance.
Gas accounted for 23%, a sharp decline from August 2021 (36%), 2022 (48%), and 2023 (35%), though still above its 17% share in August 2024. These fluctuations reflect both progress in reducing dependence on fossil fuels and the current limitations of grid storage, underscoring gas’s continued role as a flexible backup source.
Electricity imports accounted for 19%, their highest August share in the past five years and 5 percentage points higher than in August 2024. This growing dependence raises concerns about energy security and highlights the importance of strengthening domestic generation capacity and storage.
Nuclear output fell to 11%, its lowest August contribution in the past five years, down 7 percentage points from August 2024 and 4 points below its levels in August 2021–2023.
Biomass provided 8%, up from 7% in August 2024 and higher than its contributions in August 2021–2023, confirming its role as a reliable renewable source.
Solar reached 10%, its highest August share in the past five years and 2 percentage points above August 2024, reflecting favourable summer conditions and incremental growth in installed capacity.
Hydropower contributed 1%, broadly consistent with previous August levels.
Storage matched its joint-highest August contribution at 2%, equalling 2024 and demonstrating the growing role of flexibility solutions in balancing the grid.
Zero-Carbon Sources & Carbon Intensity
Zero-carbon sources; wind, solar, nuclear, and hydro, accounted for 62% of Britain’s electricity in August 2025, the highest share for any August in the past five years. This milestone reflects steady structural progress in decarbonising the grid.
Despite the strong zero-carbon contribution, carbon intensity rose to 123 gCO₂/kWh. While this was the second-lowest August value in the past five years, it was 48% higher than the record-low 83 gCO₂/kWh achieved in August 2024. The increase was driven by reduced nuclear and wind contributions alongside higher gas and import reliance.
Looking at broader trends, the 12-month rolling average for zero-carbon generation declined slightly to 51%, down 1 percentage point from the previous 12-month period. This plateau indicates a temporary slowdown in renewable integration. Meanwhile, the rolling average carbon intensity rose by 6% to 134 gCO₂/kWh, emphasising the need to accelerate clean energy deployment.
Concluding Remarks
August 2025 saw wind retain its lead as the largest generation source, though its share dipped below 2024’s record levels. Gas rebounded from its unusually low contribution last year, while imports reached a five-year August high, highlighting ongoing vulnerabilities in energy security. Nuclear’s decline to its weakest August performance in five years further compounded these challenges.
Nevertheless, the record-high share of zero-carbon sources for August, alongside growth in solar, biomass, and storage, demonstrates resilience and long-term progress in decarbonisation. Sustaining momentum will require renewed investment in renewables, reinforcement of grid infrastructure, and policies that strengthen domestic supply to ensure both cleaner and more secure electricity in the years ahead.
Britain's Electricity Summary Charts

Monthly Statistics
12-Month Rolling (Average) Statistics
To explore more insights, visit our interactive renewables map
here.
Data source: National Grid ESO 2025
(https://www.nationalgrideso.com/electricity-explained/electricity-and-me/great-britains-monthly-electricity-stats)
About the Author
Doug is a specialist in carbon reporting and research, with extensive experience in supply chain emissions, regulatory compliance, renewable energy developments and sustainability performance improvement. He holds a Master’s degree in Green Economy, which underpins his ability to interpret complex environmental data and advise on practical, impactful strategies.
At edenseven, Doug leads the production of the firm’s monthly Britain’s Electricity Generation report, delivering clear, data-driven insights into the UK’s changing energy landscape. His work supports clients in understanding market trends, emissions performance, and opportunities for cleaner energy adoption.
Doug is a Registered Environmental Practitioner (REnvP) and an IEMA Practitioner, reflecting his professional standing and commitment to advancing sustainable practices across sectors.







