Gas networks have kept Britain’s energy system afloat during this summer’s heatwaves, producing as much as 50% of the country’s daily electricity generation on one day.
Periods of intensely hot but still weather have led to reduced wind generation and increased electricity demand, due to greater use of appliances such as fans and air conditioning units.
This weather phenomenon, known as Hitzeflaute (the German term for ‘heat lull’), has impacted four extended periods of three days or more since the start of summer.
During these periods, gas power stations have been needed to balance the system and fill the gap between supply and demand. This comes despite increased output from solar PV, with gas playing an important flexibility role when solar drops at the end of the day. Wind generation has hit below 70 GWh/day on six days this year, in contrast to just three days in 2025.
Gas generated on average 36% of electricity over the course of the four Hitzeflaute periods this year, reaching a high of 50% on 30 June. On this day, gas delivered 353 GWh of power, compared with 79 GWh from wind and only 32 GWh from net interconnector imports.
Gas generation across Hitzeflaute periods averaged 257 GWh/day in 2026 in comparison to 212 GWh/day up to mid-August last year, an increase of over 20%. Outside of this year’s spells of Hitzeflaute, gas has generated around a fifth of all electricity over the summer months.
Simultaneously, extreme weather has squeezed electricity supplies across Europe, making imports less dependable. Heat and drought forced nuclear plants in France, Romania and Hungary to cut output, meaning Britain’s gas-fired power stations had to do more of the heavy lifting.
James Earl, CEO of Future Energy Networks, said:
“Britain’s gas networks have put a real shift in over a hot summer, demonstrating unprecedented flexibility to meet the high demand and low generation periods of Hitzeflaute. These striking statistics underscore how our world-class gas network is a true national asset, and why regulation must support continued private investment. The lesson is clear: a secure and resilient energy future needs gas firmly in the mix.”
Notes
The dataset containing the figures referred to in this press release is attached to the email.
Hitzeflaute impacted the following periods in 2025 and 2026:
- 30 June – 2 July 2025
- 9 July – 11 July 2025
- 16 July – 30 July 2025
- 11 August – 17 Aug 2025
- 20 June – 1 July 2026
- 8 July – 11 July 2026
- 15 July – 17 July 2026
- 13 August – 17 August 2026