Europe’s intensifying heatwaves are leaving a clear mark on household energy costs. New analysis by the environmental NGO 350.org estimates that the record-breaking heatwave that gripped much of western Europe between 21 and 27 June 2026 added more than €700 million to electricity bills in Germany and France alone.
Comparing that week against a baseline period of 14–20 June, the study found that electricity prices rose by roughly €371 million in Germany and €360 million in France. The surge was driven by higher demand for cooling, which pushed up wholesale power prices across both countries.
These additional costs come on top of already elevated oil and gas prices linked to the ongoing crisis in the Strait of Hormuz. Iran closed the strategic shipping route more than 100 days ago in response to the US-Israel offensive against the country, further tightening global energy markets.
Evening price spikes hit hardest
The analysis, based on EU electricity price and load data, reveals that price increases were especially sharp during the evening. In Germany, for instance, power prices jumped from €86 per megawatt-hour at midday to €566/MWh at 8pm on several days during the heatwave. This pattern reflects the drop in cheap solar generation after sunset, while temperatures and cooling demand remain high, particularly on so-called tropical nights.
Separate data from real-time energy newswire Montel News shows that on the evening of Tuesday 23 June, power prices in Belgium surged to more than ten times the average wholesale electricity price across the EU. Heat-related efficiency losses for solar panels and gas plants compounded the problem.
“Fossil fuel companies continue to profit from the crises they helped create,” said Andreas Sieber, head of political strategy at 350.org. “Governments should permanently tax excess fossil fuel profits and use the money to protect people from heat, bills and energy shocks.”
Public health and economic toll
The heatwave has had severe consequences beyond energy markets. It contributed to an estimated 1,300 excess deaths across Europe, including a spate of drownings as people sought to cool off in unsupervised rivers and lakes. A recent study by World Weather Attribution found that the event would have been “virtually impossible” without climate change driven by fossil fuel emissions.
Agriculture, industry and infrastructure also came under strain. In France, the June heatwave was linked to a nearly 30% rise in deaths, with the Paris region hit hardest, as reported in our earlier coverage.
A permanent windfall tax as a solution
350.org argues that a permanent windfall tax on oil and gas profits could fund climate adaptation and a just energy transition. The EU has used a similar mechanism before: after Russia’s invasion of Ukraine in 2022, the bloc introduced a temporary ‘solidarity contribution’ on fossil fuel profits, which raised €28 billion. That money was largely used to support vulnerable households.
Campaigners now say a permanent version of that tax could help offset both the costs of the Strait of Hormuz crisis and the rising financial burden of extreme heat. “The model exists and it worked,” Sieber added. “What we need now is political will to make it permanent.”
The debate comes as Europe faces a future of more frequent and intense heatwaves, with energy systems and household budgets increasingly vulnerable to climate shocks.
