What Happened: The Impact of Heatwaves on Energy Generation
Heatwaves are becoming more frequent and intense due to climate change, affecting energy generation sources worldwide. In June and July 2026, nuclear reactors were shut down, gas plant efficiency decreased, wind speeds fell, and electricity grids suffered.
Although all types of electricity generation are affected by heatwaves, some commentators point fingers at wind and solar energy while downplaying the impact on energy sources like gas and nuclear.
Why It Matters: The Real Stakes
Heatwaves increase electricity demand as people turn on air conditioners and refrigerators work harder. In France, daily electricity demand rose by almost 20% during a two-week heatwave in June 2026.
This leads to higher energy prices, as generation is stressed and demand increases, making electricity more valuable.
The Mechanism Behind It: The Science Behind Energy Generation
Nuclear energy generation is affected by heatwaves, as nuclear power plants use river water to cool reactors. When water temperatures rise, the cooling capacity is reduced, affecting the plant's efficiency.
Gas plants are also affected, as their efficiency decreases with rising temperatures. Additionally, gas turbines need air to burn gas, and hot air has a lower density, meaning less air is available for combustion.
Wind energy is less affected, but wind speeds can drop during heatwaves, reducing energy generation. Solar energy is affected by rising temperatures, but the impact is modest and is easily outweighed by the increased generation during hot days.
Bigger Picture: How This Compares to Similar Events in the Past
Heatwaves are not a new phenomenon, and energy generation has been affected by them in the past. However, the frequency and intensity of heatwaves are increasing due to climate change.
Nuclear energy generation was affected by heatwaves in 2003, 2006, 2015, 2018, 2019, 2022, and 2025. Gas plants were also affected, with their efficiency decreasing with rising temperatures.
What Happens Next: Realistic Implications and Open Questions
Heatwaves will continue to affect energy generation, and it is essential that governments and energy companies take measures to adapt to these events. This may include implementing more efficient cooling systems, improving gas plant efficiency, and expanding renewable energy generation.
Furthermore, it is crucial that energy systems are designed to be flexible and resilient, with the ability to respond quickly to changes in demand and energy generation.
Conclusion: The Impact of Heatwaves on Energy Generation
Heatwaves have a significant impact on energy generation, affecting the efficiency and capacity of power plants. However, with the implementation of adaptation measures and the expansion of renewable energy generation, it is possible to minimize the effects of heatwaves and ensure energy security.
Source / Reference
Original URL: https://www.carbonbrief.org/factcheck-how-nuclear-gas-wind-and-solar-power-are-affected-during-heatwaves
Source Name: Carbon Brief