Europe heatwave drives electricity prices to record highs

Heatwave pushes power prices higher

Europe’s late-June heatwave has driven wholesale electricity prices sharply higher, exposing how quickly power systems can tighten when demand rises and generation becomes harder to run.

Financial Times reporting on Thursday said prices reached record highs in parts of Europe during the heat event. In Germany, prices rose from about €86 per megawatt-hour at midday to €566/MWh in the evening. Great Britain also paid about £1,379/MWh to import electricity during the strain on its system.

The price spike reflects a mix of factors: more demand for cooling, lower wind output and limits on some thermal generation. It also shows how climate-driven heat can ripple through the power market even when operators say the grid remains secure.

Britain paid for emergency balance

In Great Britain, the National Energy System Operator issued a rare summer margin notice on Wednesday, signalling unusually tight available supply even though electricity was not considered at risk.

The Guardian reported that Neso later secured about 1.7 gigawatts of imports from the continent at roughly £1,400/MWh, at a total cost of about £10 million. Neso said the measures were driven by extremely high temperatures and low wind.

Summer balancing notices are uncommon in Britain, where the system is more often under pressure in winter. The intervention underlines how prolonged heat can create the same kind of emergency balancing pressure that operators usually prepare for in colder months.

French reactors were reduced

France’s nuclear fleet was also affected. Le Monde reported on Wednesday that EDF reduced or stopped output at several reactors, including Golfech, Nogent-sur-Seine and Bugey, as river temperatures rose.

Those reductions affected about 4.6% of France’s nuclear capacity, according to the report. The limits are tied to cooling requirements and rules meant to protect aquatic life when rivers become too warm.

The Guardian later reported that EDF temporarily shut two reactors at Nogent-sur-Seine and Bugey to comply with river-temperature limits. France’s grid operator RTE said the overall electricity system remained secure despite the curtailments.

France’s reliance on river water for cooling makes it vulnerable when hot weather lasts long enough to push water temperatures higher. That leaves operators with fewer options just as demand is rising.

What the spike means

The episode shows how several stresses can arrive at once in a heatwave. Households and businesses use more power for cooling, wind generation can weaken, and some plants may have to cut output because of cooling constraints.

That combination forces grid operators to lean on imports, reserve plants and emergency balancing measures, all of which are more expensive than normal trading conditions. Consumers may not see the market prices directly, but the wider cost is carried through the power system.

For now, operators in Britain and France are saying the grid remains secure. The immediate issue is not blackouts, but the cost of keeping supply reliable while temperatures stay high.

Further reports will show whether the heatwave lasts long enough to trigger more reactor curtailments, additional import purchases or fresh supply notices across Europe.