Drought and heat push Europe’s power grid to breaking point

On 4 August, Hungary’s prime minister Péter Magyar addressed the nation live from the Paks nuclear power plant, which sits on the banks of the Danube river. Normally Paks generates 40 per cent of Hungary’s electricity, but a vicious drought has drained water from the Danube, forcing plant operators to shut down all but one of its eight turbines for the first time in its history. It leaves Hungary short of the power it needs during the latest heatwave of the long hot summer of 2026. Temperatures across Europe climbed towards 40°C (104°F) once more this week, prompting a surge in power demand largely due to increased air conditioning use. Advertisement Standing on parched ground near the plant, Magyar pleaded with citizens to use electricity wisely, especially during the evening peak hours of 5pm and 10pm. He warned the days ahead will be “critical” in determining whether the country’s energy crisis deepens. Companies across Hungary are voluntarily curbing their power consumption, and non-essential lighting at public buildings has been switched off during the night. The problem isn’t limited to Hungary. Across southern and eastern Europe, nations are struggling with the impacts of successive heatwaves and a prolonged drought. In Romania this week, naval engineers blew up a rock outcrop to help more water flow from the Danube towards the country’s Cernavodă nuclear plant, in a bid to avoid a total shutdown. Slovenia and France have also had to shut down nuclear reactors in the face of high temperatures and low water levels. At the same time, power demand can jump by around 20 per cent during a heatwave, due to a spike in air conditioning use. “The extra heat is driving a lot of increased demand and the drought is causing is a reduction in supply, particularly with these nuclear units,” says Fintan Devenney at energy analyst Montel. “So the two things together are certainly creating something of a perfect storm.” Other power generators are struggling too. Europe’s hydropower generation fell to its lowest levels in more than a decade in July, according to energy think tank Ember. Gas power plants have been forced to reduce their output as they struggle to stay cool when outside temperatures climb, with almost one third (32 per cent) of Italy’s gas fleet threatened by a lack of cooling water from rivers and canals, according to Montel. Finally, low wind speeds have dampened output from turbines. Solar has been the one bright spot, with clear skies and sunny weather delivering record levels of generation across the European Union in June 2026, according to Ember. In Hungary, for instance, solar has provided as much as 80 per cent of the country’s power during the day. But without battery storage, solar is of little use for the evening peak, when long hot evenings mean people keep their air conditioning running into the early hours. Europe is suffering what is already clear to be a record-breaking summer of heat. June 2026 was the hottest June on record for the continent, with the extreme heat and dry weather continuing into July and August. Drought and heatwaves have caused issues before with Europe’s power supply, bringing power outages and reductions in nuclear power output in France and Switzerland in 2025. But this summer has been “unprecedented”, says Devenney, pointing to the low river levels on the Danube. “These levels have never been really seen before. The Paks nuclear plant in Hungary, to my understanding, hasn’t been switched off before. It’s never seen sort of levels of production as low as they currently are,” he says. “There are people [in Hungary] saying how are we going to meet this electricity demand? How are we going to keep the lights on?” So far, supply has been maintained without any blackouts, but the price of power in some countries – particularly during the evening peak – has skyrocketed. Earlier this week, wholesale power prices during the evening peak exceeded €300 per megawatt hour in Poland, Slovakia, Romania and Hungary, a sign of how tight supply was to the market. Normal prices would be between €100 and €150 per megawatt hour. With little rain forecast for the coming days, how long the power supply crunch will last is uncertain. Rivers will take weeks of prolonged rain to recharge fully. “It’s hard to see those nuclear plants on the Danube resuming operation within the next few weeks. I would expect hydropower to remain at very low levels into August as well,” says Chris Rosslowe at Ember. The key outstanding question, he says, is how power demand may shift. “We just don’t know whether we’ll get some relief from these high temperatures. So I think a lot could depend on that.” So far, European nations have avoided having to impose power rationing, rolling blackouts or other more severe curbs on demand during severe heatwaves. Energy planners expect more investment in solar, energy storage options and grid flexibility will improve countries’ abilities to manage such extremes in the future. But for now, in Hungary and elsewhere, there is little that can be done other than hope for a break in the weather.