A surge in solar power helped meet heightened electricity demand across Europe during blistering heatwaves, while average daily electricity prices jumped 119 per cent higher in Hungary, 44 per cent in France, 13 per cent in Italy and seven per cent in Spain than on comparable days in the preceding weeks. The numbers come from a new analysis by energy think-tank Ember, and they show how quickly Europe’s electricity system turns a climate emergency into a market event, with households and workers left to absorb the cost.
The Grid Under Heat
Ember found that solar output in European countries rose by up to 17 per cent on heatwave days in June and July. Researchers said the extra generation helped power the grid as electricity demand increased by as much as a quarter on hot days. Heatwaves often trigger a spike in electricity consumption because of the sudden need for cooling, mainly from energy-intensive air conditioning units. The system doesn’t bend for people. It charges them for surviving the weather.
The International Energy Agency estimates that space cooling, which is mostly air conditioning units and fans, consumed around seven per cent of the world’s electricity in 2022. Even in countries where air conditioning ownership is low, countries experience energy demand spikes when scorching temperatures hit. During the early summer heatwaves of 2025, France recorded an evening electricity peak that was 25 per cent above the off-season average because of air conditioning. The pattern is blunt enough. Climate pressure rises, demand rises, and the grid becomes another site where ordinary life gets priced and managed.
Ember’s analysis found that during the late-June heatwave this summer, daily electricity demand rose by up to 28 per cent in Italy, 23 per cent in Hungary, 14 per cent in France and 13 per cent in Spain compared with pre-heatwave days. It said solar was the only major power source to perform better than usual as heatwave-driven demand increased. Compared with other days in June and July, average daily solar generation during the heatwaves was 17 per cent higher in France and Hungary, five per cent higher in Spain and the same in Italy. Solar kept the lights on while the rest of the system strained. The market still found a way to make the crisis expensive.
After Sundown, the Bill Arrives
Senior energy analyst Chris Rosslowe said, “Solar is already doing heavy lifting during heatwaves, but the real challenge starts after sundown.” He said, “In the evening, when cooling demand is still high, the grid is most exposed to expensive gas-fired power.” That’s the familiar arrangement: cheap generation when the sun is up, costly fossil backup when people still need power and the market wants its cut.
Europe’s back-to-back heatwaves, which scientists say would have been virtually impossible if it weren’t for climate change, have triggered mass droughts across the continent. Low water levels along the Danube River forced nuclear output to be curtailed in Hungary, while experts warned that hydropower neared an all-time low in the Alpine region. Fossil-fuelled energy has also suffered from the drought, with Poland forced to reduce output at a coal-fired power plant because of critically low water levels in the Vistula River. The climate crisis keeps hitting the same infrastructure from every side, and the system answers with scarcity, curtailment and higher prices.
The late-June and early-July heatwaves also saw average daily electricity prices surge 119 per cent higher in Hungary, 44 per cent in France, 13 per cent in Italy and seven per cent in Spain than on comparable days in the preceding weeks. Experts said the price surge underlined the need for battery storage systems, which can prevent excess solar energy from being wasted. Rosslowe said, “While solar saves the day, battery storage can save the evening.” He added, “Together, they are one of the clearest ways to make Europe’s power system more resilient in the hotter summers. As solar output rises during heatwaves and other power sources struggle, storage can carry that cheap electricity into the evening.”
That’s the language of resilience, translated into the language of the market. The grid gets praised when it survives, while the people paying the bills are expected to treat a 119 per cent price surge as a technical adjustment. Europe’s energy order keeps presenting itself as management. On the ground, it looks a lot more like rationing by price.