Record EU solar generation helped stabilize power supply during heatwave

A record 45 TWh of solar power was generated across the European Union in June, which helped stabilize electricity supply during the recent heatwave, according to think tank Ember.

Record volumes of solar helped to keep Europe’s electricity grids stable through a heatwave in late June and early July, according to a new report by London-based energy think tank Ember.

Ember’s latest report, “Heat and power: Impacts of the 2025 heatwave in Europe,” said the heatwave that culminated between June 28 and July 2 increased daily power demand by up to 14% as the use of air conditioners soared.

This surge in demand, coupled with outages of thermal power plants and capacity reduction in nuclear plants across several European countries, led to a two to three times increase in average daily power prices. On the hottest days, electricity prices exceed €400 ($468.53)/MWh.

Ember said the challenges brought by the heatwave were partially offset by the large volumes of solar energy produced. The European Union generated a record 45 TWh of solar electricity in June, the highest monthly total to date, with several countries also setting new daily solar production records.

In the peak days of the heatwave, solar delivered up to 50 GW of power in Germany alone, generating more than one-third of the country’s electricity. Ember’s report adds that Germany’s 14 GW of battery storage and 10 GW of pumped storage was then used to store some solar to use after sunset.

With heatwaves set to become more frequent in Europe, Pawel Czyzak, Ember’s Europe program director, said that battery storage, interconnection, demand flexibility and dynamic tariffs should become a key part of grid planning and power market design.

“The biggest opportunity is to store solar electricity, to help power air conditioning well into the evening,” added Czyzak.

Ember also called for the use of smart electrification and time of use tariffs for solar energy, as it could unlock consumer savings and ease grid balancing at times of stress, such as during heatwaves.