French Power Prices Turn Negative as Heat Dome Lifts Solar to Nearly 50% of UK Demand
Updated
Updated · The Cool Down · May 29
French Power Prices Turn Negative as Heat Dome Lifts Solar to Nearly 50% of UK Demand
1 articles · Updated · The Cool Down · May 29
Summary
France’s hourly electricity prices fell below zero around 1 p.m. Tuesday as an early-season heat dome flooded the grid with solar power.
Clear skies under the high-pressure system pushed temperatures 9 to 15 degrees Celsius above normal, while solar supplied nearly half of UK electricity demand near midday Sunday — a record share.
The same heat wave strained infrastructure elsewhere: London reached a May-record 35 C, France logged its hottest May day Monday, and water-service failures hit hundreds of households in parts of England.
Wind generation was weaker than usual across countries including Germany, Spain, Italy and France, highlighting how extreme weather can rapidly shift Europe’s clean-energy mix.
Month-ahead power prices still rose on concerns that hotter, drier conditions could curb hydropower and force nuclear cutbacks as warm rivers limit reactor cooling.
As solar power surges during heatwaves, how can our energy grids handle this success without becoming unstable?
With homes built for cold, is Europe facing a massive, unaddressed public health crisis every summer?
Europe's 2026 Heatwave, Negative Power Prices, and the Urgent Need for Grid Flexibility and Storage
Overview
In late May 2026, a persistent high-pressure heat dome caused a severe heatwave across northwest Europe, with temperatures soaring 9°C to 15°C above normal. London hit a record 35°C, and France issued widespread heat alerts. The intense sunshine led to a surge in solar power output, but this oversupply sometimes pushed electricity prices below zero. While renewables like solar and wind grew rapidly, the grid struggled to absorb all the energy, revealing bottlenecks in storage and infrastructure. These events highlight the urgent need for flexible grids and better storage to support Europe’s clean energy transition.