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By Euronews Green
Published on
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This summer, Europe has again been gripped by a series of intense and widespread heatwaves. This week alone, temperature records have been broken across south-west France, Croatia and Hungary, with some regions enduring highs of over 40°C.
As climate change makes heatwaves more frequent and more intense, demand for energy is soaring as people attempt to keep cool. At the same time, high temperatures are undermining electricity supplies, particularly from thermal plants – a type of power station in which heat energy is converted into electricity – that rely on river water for cooling.
Experts warn that heatwaves are putting the continent’s power grid under severe stress. They say energy systems urgently need to adapt, increasing flexibility and transitioning to renewable energy to avoid planet-warming fossil fuels.
Governments also face the challenge of coping with heatwaves without blackouts or increasing planet-warming emissions.
Energy consumption increases as people try to keep cool
Recent heatwaves are a “stark reminder” that Europe’s power system needs to be prepared for increasingly extreme temperatures, according to energy think tank Ember’s Europe policy director, Pawel Czyak.
“Europe’s power systems are once again being tested by record-breaking temperatures.”
Czyak adds that the think tank’s analysis of the July heatwave showed how soaring demand from cooling pushed electricity demand to summer peaks. In Spain, electricity use jumped by around 14 per cent. Germany and France saw demand spike during peak hours, putting power operators on high alert.
High summer temperatures are rapidly becoming the norm, and as they do, air conditioning systems are becoming an increasingly common sight. The number of room air conditioners in the EU is predicted to rise from less than 7 million in 1990 to more than 100 million in 2030.
Despite this dramatic increase, air conditioning still only makes up around 0.6 per cent of household energy use in Europe
Data shows that Italy is by far the EU’s biggest user of air conditioning. It accounts for one-third of all electricity consumed by air conditioning across the 27 member states, despite having some of the highest electricity prices in Europe. In second place is Greece, followed by France, Spain and Germany.
Pressure on power plants as temperatures rise
Heatwaves don’t just increase demand for electricity; they can also reduce power production from some forms of energy.
Several European countries have had to repeatedly reduce electricity production or shut down nuclear reactors due to extreme heat this summer.
During the heatwave between 28 June and 2 July, 17 out of France’s 18 nuclear power plants in the country faced capacity reductions, with some shut down completely.
The latest heatwave saw multiple warnings of power reductions, particularly on the Rhône river in the east and on the Garonne in the west of the country. Around three-quarters of the country’s mainland faced heat alerts on Wednesday, and temperature records were broken in the southwest.
So why is extreme heat a problem for nuclear power stations? To cool down reactors, water is pumped in from local rivers or the sea. It is then released back out at a higher temperature.
But heatwaves mean the water being pumped in is already hot to begin with. It impacts the plant’s ability to use it to cool down, and if the water that’s released is too hot, it can threaten local biodiversity.
Built for milder, more predictable climates, Europe’s grid itself also struggles in extreme heat. In early July, blackouts hit parts of Rome, Florence, Bergamo and Milan as Italy’s ageing infrastructure was pushed to its limits by the weather.
The strain to balance the system due to a surge in electricity demand from cooling systems was partly to blame. But energy provider Enel said that underground cables had also expanded and overheated. In high temperatures, the underground cables struggle to dissipate heat.
Without efforts to upgrade the grid and make it more resilient to extreme weather, the direct stress test of increasing heatwaves could lead to more blackouts like those seen in Italy.
Can renewables help electricity grids adapt?
While sunny conditions bring heat, they can also bring more electricity generation.
June 2025 saw the highest monthly EU solar electricity production on record, amounting to more than 40 per cent of generation in the Netherlands and 35 per cent in Greece.
The solar boost kept the electricity grid well supplied during daylight hours. It was most abundant at midday when there was the greatest demand from air conditioning, helping to ease the strain on the grid and prevent blackouts.
“Thermal plants saw outages, driven by cooling challenges in nuclear facilities, whereas strong solar performance helped stabilise strained grids,” says Czyzak.
“Investing in flexible, renewable-powered grids will help the power system be resilient and keep costs low.”
Elsewhere, July heatwaves caused wind power outputs to crash. During an unprecedented spate of high temperatures, Finland saw wind power production plummet, with generation among the weakest on record. The country turned to hydropower, but this alone was not enough to cover the production gap.
Wind turbines almost ground to a halt in the UK this week as the heatwave brought calm conditions. Wind accounted for only 5 per cent of the energy mix on Wednesday, with gas jumping to more than a third, according to data from the National Energy System Operator.
These extremes underline solar’s growing role in heatwave resilience, but they also show that renewables alone are no silver bullet unless supported by storage and smarter grids.
