Europe’s record-breaking June heatwave has sharply increased electricity demand and driven wholesale power prices higher across the continent, highlighting the growing strain that rising temperatures are placing on energy systems as demand for cooling continues to grow.

Extreme temperatures across several European countries have led households, businesses and offices to rely more heavily on air conditioning and other cooling systems, increasing electricity consumption at a time when some sources of power generation have been constrained.

Although air conditioning remains less common in Europe than in many other regions, its use has been expanding steadily. According to the International Energy Agency (IEA), around 20 percent of European households now have air conditioning, and ownership has risen by about 50 percent over the past decade. Annual sales have also increased by roughly 30 percent over the last five years.

The latest heatwave saw temperatures reach record levels across the continent. Germany recorded 41.7 degrees Celsius in the eastern town of Coschen on June 28, while France experienced its hottest June day on record, with temperatures climbing to 43.8 degrees Celsius in Palluau. Spain also registered record June temperatures during the same period.

Data from Eurelectric showed electricity demand rose significantly across the European Union’s four largest economies as temperatures climbed. In Germany, daily electricity consumption increased from 1,267 gigawatt-hours on June 11 to 1,396 gigawatt-hours on June 25. France recorded an even larger increase, with demand rising from 1,048 gigawatt-hours to 1,255 gigawatt-hours over the same period. Italy and Spain also reported noticeable increases.

France experienced the largest rise, with electricity demand climbing by nearly 20 percent within two weeks. French grid operator RTE said electricity consumption typically increases by between 0.7 and 1 gigawatt for every one-degree Celsius rise in temperature during heatwaves.

The surge in demand was reflected in wholesale electricity markets. According to Eurelectric, wholesale electricity prices climbed sharply in Germany, France and Spain, reaching their highest levels between June 23 and 24 as temperatures peaked.

Germany recorded wholesale electricity prices exceeding €200 per megawatt-hour, while prices in France approached €160 per megawatt-hour. Spain also saw prices rise above €110 per megawatt-hour.

Supply constraints added to the pressure. Wind power generation in Germany declined during the hottest days, increasing reliance on more expensive gas and coal-fired generation. In France, state-owned utility EDF reduced nuclear output by 4.1 gigawatts after river water temperatures became too high to safely cool several reactors.

Eurostat data shows household energy use for cooling has roughly doubled across the European Union since 2015, although cooling still accounts for only 0.8 percent of the bloc’s final energy consumption.

IEA energy efficiency policy analyst Fabian Voswinkel said Europe’s electricity systems are capable of managing higher cooling demand, provided investments continue in energy-efficient cooling technologies, flexible electricity networks and renewable power generation. He added that solar energy is expected to play an increasingly important role because peak cooling demand generally coincides with peak solar electricity production during daylight hours.