Slovenia's Krško plant cuts power in heatwave

The timing also matters for investors in European utilities and power traders. Hot weather typically boosts spot electricity prices, while outages or curtailments at nuclear stations can widen the gap between available supply and demand, especially in a region where cross-border flows are crucial and backup generation can be expensive.

The broader backdrop is a tense summer for energy markets, with heatwave risk intersecting with already elevated attention on inflation, fuel costs and power reliability. In the U.S., conventional technical indicators on utility-linked stocks such as Engie and E.ON show both names trading near their 50-day moving averages, while the S&P 500 and the dollar remain in strong risk-on territory, leaving power-market shocks more likely to be driven by weather than by broad macro stress.

For now, the key question is how long the heat persists and whether other European plants face similar cooling limits. Any further power reductions, unplanned outages or restrictions on river water use could keep regional electricity prices elevated into August and test utilities’ ability to pass through higher costs.