IN LONDON: Europe has experienced its first major heatwave of the season, with the UK being affected by a record-breaking heat of over 35℃ in May 2026, resulting in negative electricity prices.
GridX reports that negative electricity prices occur due to an oversupply of electricity, often during peak production periods for renewable energy sources, such as wind and solar power.
Europe’s latest heatwave has caused a spike in solar power output, which has resulted in the wholesale market of electricity dipping below zero due to supply outstripping demand.
According to a recent Bloomberg report, the UK saw solar meet almost half of its electricity demand at around midday on 24 May 2026, as London temperatures surpassed 32℃ — representing the highest ever recorded as reported by data from the UK’s National Energy System Operator (NESO).
Around 269,000 solar deployments were installed across the UK in 2025, recording the strongest year for installations. Roughly 255,000 of these were rooftop sales, meaning at least 95% of all new solar was installed in homes, businesses, and other buildings.
This news comes ahead of the UK surpassing two million total solar installations as of March 2026. The surge in solar installations reflects the UK Government’s investments in delivering clean energy and helping lower bills.
Energy Secretary Ed Miliband says as the nation faces a second fossil fuel crisis in five years, Britain is taking control of its energy.
“Record-breaking solar growth means greater energy security, lower exposure to volatile fossil fuel markets which we can’t control,” Miliband says.
Other parts of Europe
In France, the surge in renewable power also pushed hourly prices below zero on 26 May, while the nation experienced a highly anomalous and powerful heat dome.
According to analytical firm Montel, negative electricity prices on the Iberian Peninsula hit a new all-time high in Q1 2026.
Spain was also hit with negative electricity prices during this year, recording 397 hours of negative prices between January and March 2026. This represents a significant increase in comparison to 48 hours of negative prices in the same period the previous year.
According to Ember Energy, more than 120 gigawatts of anticipated renewables are at risk due to Europe’s “insufficient grid capacity.” This includes 16 gigawatts of rooftop solar installations, impacting more than 1.5 million households across Europe.
Storing excess electricity is considered difficult, which has resulted in calls to strengthen Europe’s battery energy storage systems (BESS).
In 2025, the EU installed 27.1 gigawatts per hour of new BESS, as reported by SolarPower Europe. To meet the continent’s 2030 targets, the EU is required to scale its battery storage towards 750 gigawatts per hour within the next five years.
Write to Aaliyah Rogan at Mining.com.au
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