Europe's power grids are already under pressure and it is only early June.

Europe's first major heatwave of 2026 arrived weeks ahead of schedule. A heat dome parked over Western and Central Europe in late May, running temperatures 12–16°C above seasonal norms. France recorded its hottest national average May temperature on record (24.9°C on 26 May), with Angoulême reaching 37.8°C on 28 May. Portugal hit 40.3°C on 27 May – a new national May record, with 22 weather stations setting all-time highs the same day. The Netherlands broke its record for 26 May with 30.4°C in De Bilt. Belgium hit 31°C in Brussels. Luxembourg set a new May record at 33.6°C. Spain approached 38°C inland.

And the grids felt it immediately. In France, hourly prices on the Epex Spot exchange turned negative around 1 p.m. on 26 May as solar flooded the grid. In Germany, solar generation had already reached 50 GW on the hottest days of the 2025 heatwave – covering up to 39% of national demand. By evening in both cases, the picture reversed sharply.

This is not an isolated event. It is the new pattern.

As heatwaves spread across Western Europe, electricity demand for cooling surges, while solar production floods grids with cheap midday energy. The result is a new energy paradox: extremely low prices during the day, followed by sharp evening peaks when millions return home, turn on air conditioning, and plug in EVs at the same time.

This is exactly where smart charging becomes critical.

Why Heatwaves Are Becoming an Energy Problem

Europe’s electricity system was not designed for prolonged heatwaves combined with mass electrification.

During extreme temperatures:

• Air conditioning demand spikes sharply
• Grid congestion increases
• Electricity prices become more volatile
• Peak demand shifts later into the evening

At the same time, solar generation reaches record levels during the day.

This creates a strange imbalance:

• Too much electricity at noon
• Not enough flexibility in the evening

And that flexibility problem is growing fast.

Midday Solar Surplus Is Growing Across Europe

In countries like the Netherlands, Belgium, Germany, France, Spain and Denmark, solar generation during sunny summer days can push electricity prices to zero or below.

This is no longer a rare anomaly and the chart below shows just how fast this is accelerating.

During the May 2026 heatwave, French prices on the Epex Spot exchange turned negative at 1 p.m. on 26 May as solar supply outpaced demand by a wide margin. In Germany, solar output reached 50 GW at peak during the July 2025 heatwave – generating up to 39% of national electricity demand in a single day. In Belgium and the Netherlands, unusually sunny conditions in 2025 alone boosted solar output by 26% and 21% respectively compared to prior years.

Without flexible demand to absorb this surplus, a growing share of renewable energy risks being curtailed or simply wasted.

The Evening Peak Problem

The challenge begins when the sun starts to disappear.

Around the same time:

• people return home
• cooling demand remains high
• cooking demand increases
• EVs begin charging simultaneously

This creates sharp evening peaks that stress local grids and push prices upward.

In 2026, with 15-minute pricing now active in many European markets, these swings are sharper than ever. During the July 2025 heatwave, evening prices spiked above €470/MWh in Poland and €400/MWh in Germany. Average daily prices rose 175% in Germany and 108% in France during that same week – while midday solar was, at times, effectively free.

EVs Can Either Stress the Grid or Stabilise It

Electric vehicles are often discussed as a future grid challenge. But the reality depends entirely on when they charge.

Why Smart Charging Matters More Than Ever

This flexibility only works if charging becomes intelligent.

And all of it happens automatically without the driver doing a thing.

The Energy Transition Needs Flexible EV Charging

Europe is rapidly adding solar generation, electric vehicles, electrified heating, and battery storage. But infrastructure expansion alone is not enough.

The IEA projects EU electricity demand to grow around 2.3% per year through 2030, with solar set to reach 20% of EU generation by 2030. More than 400 GW of renewable capacity is expected to be added between 2026 and 2030, with 70% coming from solar alone. A 2026 Solar Power Europe report meanwhile warns that more than 120 GW of anticipated renewable capacity is at risk due to insufficient grid infrastructure – including 16 GW of rooftop solar affecting over 1.5 million households.

The next phase of the energy transition will depend heavily on software orchestration: coordinating flexible demand, balancing renewable variability, and optimising energy flows in real time.

Smart EV charging is one of the fastest scalable flexibility solutions available today.

Simple Ways EV Drivers Can Reduce Summer Charging Costs

The Bottom Line