Evening power spikes hit €1,038 in Belgium

Germans call it Hitzeflaute: a "heat lull." A heatwave settles over the continent, temperatures stay high, but wind speeds drop to almost nothing. Solar panels flood the grid at midday, then fade. Air conditioners keep running into the evening. Last week, that collision produced record evening electricity prices across northwestern Europe (PV Magazine).

Midday surplus, evening squeeze

Europe's power markets use merit-order pricing: the cheapest generators run first, and the most expensive plant still needed to meet demand sets the price for everyone in that hour. At noon on a sunny day, solar drives that price close to zero. By 8 p.m., with panels dark and wind absent, gas turbines are the last plants running. They set the price.

Belgium hit €1,038.25/MWh in a quarter-hourly settlement, the Netherlands €902.47/MWh, and Germany €747.10/MWh, all in the same evening window (PV Magazine). Spain shows the timing most clearly: its daily average was €112.42/MWh, but the peak reached €185/MWh between 21:00 and 22:00, when solar had gone (RTVE).

The supply side compounded things. Wind generation fell 50% in France, 49% in Germany, 43% in Italy and 33% in Spain during the week of 15 June (AleaSoft). France, normally Europe's biggest nuclear power exporter, lost 4.1 GW of nuclear output because rivers used for reactor cooling were too warm. Electricity exports dropped from 10–12 GW to around 3 GW (Reuters). Heat didn't just silence the wind. It weakened the backup generation that was supposed to compensate.

Cross-border power cables are designed to smooth local shortages by moving cheap electricity from one country to another. When several countries are short in the same hours, there is no cheap surplus to share. ACER, the EU's energy regulator, already assesses reserve needs regionally rather than country by country, acknowledging this shared exposure (ACER).

Who absorbs the spike

The bill depends on your contract. Dutch households on dynamic contracts (where the price tracks the hourly wholesale market) faced around €1.20/kWh at 20:45. Customers on fixed-rate contracts felt nothing that evening (Keuze.nl, DutchNews). Dynamic contracts are central to Europe's plan for managing variable renewables: they reward people who shift electricity use to cheaper hours.

That only works when people can actually move their demand. Renters, elderly people and families in poorly insulated flats who need cooling after sunset have the least room to do so. In Spain, average household cooling costs rose from €110 in 2022 to €155 in 2025, while only 41% of homes have air conditioning (El Independiente). Those without cooling don't appear in price data. The cost registers in health systems instead.

The winners are the assets that can deliver when others cannot: gas peaker plants (turbines kept on standby for exactly these hours), battery operators and flexible hydropower. All earn more when evening scarcity pushes up the value of power you can switch on at will (Euronews).

The gap is after sunset

French and Polish grid operators both said overall supply remained adequate, and Nordic wholesale prices actually fell during the same week (Le Monde, AleaSoft). The grid held. But the prices revealed a timing mismatch: Europe can produce abundant cheap solar at noon and still lack enough batteries, customers paid to shift their demand, and grid capacity that isn't already full to carry that surplus into the evening when people need to cool down.

The political question is whether Europe builds that evening flexibility before heatwaves make dynamic pricing too painful for voters to accept. Each summer of record evening spikes makes fixed-rate contracts look safer, and that retreat would slow the very demand-shifting the grid needs most.