Gas Topped Britain’s Electricity Mix on Sunday, Supplying Over a Quarter of Power

Gas generated 27.3% of British electricity on Sunday, making it the single largest source of power for the day, according to data published by the National Energy System Operator.

Imports came in second at 21.8%, followed by nuclear at 18.4%. Renewable sources combined for 30.7%, with wind at 13.0%, biomass at 9.2%, solar at 7.1%, and hydro at 1.4%. Other sources made up the remaining 1.9%.

A Grid Still Leaning on Gas

The figures show that gas and imports together provided nearly half of all electricity on the day. That reflects conditions where dispatchable power was needed to keep the grid stable, something gas plants can provide but most renewables cannot.

Unlike wind and solar, gas-fired stations can be switched on or off to match shifting demand. That flexibility has kept gas embedded in the British electricity mix even as renewable output has grown sharply.

Throughout 2025, gas accounted for 31.5% of total UK electricity generation, reaching 91.6 terawatt hours. Sunday’s 27.3% figure sits below that annual average, suggesting some improvement, though gas remains dominant.

Renewables Setting Records, but Not Every Day

The Sunday snapshot stands in contrast to recent milestones. On March 25, 2026, wind alone supplied 60% of Britain’s electricity, setting a generation record of 23,880 megawatts, enough to power over 23 million homes. On that day, gas fell to just 2.3% of the grid.

Solar also broke records. On April 23, 2026, output reached 15.4 gigawatts for the first time, powering roughly 11 million homes at peak. The UK added over 27,000 solar installations in March 2026 alone, the highest monthly total since 2012.

For the full year 2025, renewables reached a record 52.5% of electricity generation, the second consecutive year that clean sources exceeded half of total output.

Sunday’s renewable share of around 30.7% shows how sharply generation can swing depending on weather and season.

Nuclear Output Is Falling

Nuclear’s 18.4% share on Sunday came against a backdrop of declining capacity. Output fell to 35.9 terawatt hours in 2025, a 12% drop from 2024 and roughly half of 2015 levels.

Aging reactors and extended outages have driven the decline. In the fourth quarter of 2025, nuclear output contracted to just 8.3 TWh.

The government published its Advanced Nuclear Framework in February 2026, aiming to attract private investment in new reactor designs. But no new capacity is expected in the near term, leaving a gap that renewable energy and imports must fill.

Imports Fill the Gap

The 21.8% import share on Sunday reflects Britain’s continued reliance on undersea electricity links to France, Belgium, and the Netherlands.

Overall, net imports fell 11% in 2025 to 29.7 TWh, partly because domestic renewables displaced the need for foreign power on high-wind days. But when renewable output dips, the interconnectors remain critical to keeping the lights on.

The UK still imported 46% of the primary energy used for electricity in 2025. Recent rises in global gas prices, driven partly by supply disruptions, have made that dependency more costly and reinforced the economic case for expanding domestic renewables.

The 2030 Target

The UK government’s Clean Power 2030 plan calls for clean sources to provide at least 95% of electricity by the end of the decade. That would require cutting carbon intensity from 171 gCO2e per kilowatt hour in 2023 to below 50 gCO2e/kWh.

On April 22, 2026, the grid briefly reached 98.8% zero-carbon generation, a new record that showed what is technically possible under ideal conditions.

Reaching that level consistently will require far more offshore wind, solar, and battery storage, along with major upgrades to the grid itself. Currently, over 700 gigawatts of generation and storage projects are waiting in the queue for a grid connection, creating a significant bottleneck.

Sunday’s numbers show how much ground remains to be covered.

References

• UK Energy Trends and Prices Statistical Release, Department for Energy Security and Net Zero, April 2026
• RenewableUK Press Releases and Analysis, 2026
• Clean Power 2030 Action Plan, UK Government