Heatwaves Threaten Europe's Electricity Grids
An open-source toolkit developed by Cambridge and Hong Kong researchers finds France, Spain and Italy most exposed to heat-driven grid failure.
Updated on Nov. 13, 2026 in Energy
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Researchers from the University of Cambridge, City University of Hong Kong and The Chinese University of Hong Kong (Shenzhen) released the first open-source toolkit to help national grid operators assess how high heat affects power systems. Model simulations based on the 2019, 2022 and 2024 heatwaves show France, Spain and Italy at highest risk of supply bottlenecks and possible grid failure.
Why it matters
Heatwaves raise cooling demand while cutting solar output and weakening wind, and heat can force power lines to sag and reduce what they can carry. The study found hidden bottleneck regions that existing methods missed, suggesting current storage may be insufficient to prevent load shedding.
The model is based on three heatwaves in 2019, 2022 and 2024 and covers eight Western European countries. Its projections assume only a conservative annual demand increase over five years and exclude datacentre growth, so the scale of the risk under faster demand expansion is not yet quantified.
The players
University of Cambridge
A public research university in England, founded in 1209, known for its science and engineering research programs.
City University of Hong Kong
A public university in Hong Kong focused on applied science, engineering and technology research.
The Chinese University of Hong Kong (Shenzhen)
A campus of The Chinese University of Hong Kong located in Shenzhen, China, with a focus on science and engineering.
The details
The team released HEAT-Analysis, an open-source toolkit with data sets, algorithms and source code, to help national operators see how high heat affects power grids. Heat increases cooling demand, reduces solar panel efficiency and can force conventional and nuclear plants to cut output, while high-pressure weather systems that bring heat also bring low winds that stall wind farms.
Timeline
2019: First of three heatwaves studied in the long-term analysis.
2022: Second heatwave studied in the long-term analysis.
2024: Third heatwave studied in the long-term analysis.
Next five years: Conservative annual demand increase assumed in the model.
The Big Picture
The study, published in Nature Energy, extends peer-reviewed grid resilience research by introducing an open toolkit that maps bottlenecks existing methods missed. It shifts attention from average demand toward the compounding effects of heat on generation, transmission and storage across interconnected European grids.
Heat-driven grid stress could eventually affect electricity reliability for households and businesses in the most exposed countries if demand grows faster than assumed. The toolkit gives national operators a way to test where bottlenecks would form before heatwaves arrive.
The takeaway
Grid planners who model only average demand may miss heat-driven bottlenecks that appear during extreme weather. Testing grids against recent heatwaves can reveal vulnerabilities before they cause outages.
Further reading
Explore more on how heat and climate shape power supply in our Energy coverage.
Source note: This article includes information reported by University of Cambridge.
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