Heat wave and solar eclipse send Europe power prices soaring

A rare convergence of extreme summer heat and a solar eclipse sent European wholesale electricity prices surging on Wednesday, with spot prices in Germany more than doubling during the eclipse's peak, exposing the vulnerability of the continent's increasingly solar-dependent power grid.

Prices Spike as Eclipse Blocks Solar Output

Spot electricity prices for 15-minute periods around the peak of Wednesday evening's partial solar eclipse reached as high as 461.17 euros per megawatt-hour in Germany, more than double the price at the same time on Tuesday, according to European Power Exchange data. Intraday power prices in France and Germany peaked well above €300 per megawatt-hour from 8 p.m. to 9 p.m. local time, surpassing the day-ahead prices set the previous day — a sign the market had tightened further.bloomberg+2

The eclipse is expected to reduce Europe's solar output by about 9.7 gigawatts between 7:15 and 9:30 p.m., according to a forecast from Entso-e, the group of European power grid operators. Spain, where the eclipse will be total, faces the largest drop in solar generation. In the UK, the National Energy System Operator warned of tight margins for Wednesday evening and asked market participants to offer spare generation.theedgemalaysia+1

Heatwave Compounds Supply Crunch

The eclipse struck against a backdrop of prolonged heat that has already strained Europe's power system. A high-pressure heat dome is expected to push temperatures to 40°C in parts of France through the weekend, with London forecast to reach 37°C on Thursday.theedgemalaysia

France's nuclear fleet — the backbone of European power supply — has been hit hard, with high river temperatures forcing reactors to curb output or shut down. An influx of jellyfish at a coastal site knocked out more than three gigawatts of generation this week. Romania and Hungary have also curtailed nuclear generation as Danube water levels fall.insiderpaper+1

"We clearly right now see a very hot summer that is curtailing output, which is going to lead to short-term distortions," E.ON chief executive Leonhard Birnbaum told Bloomberg TV on Wednesday.theedgemalaysia

Structural Vulnerability on Display

The price swings underscore the volatility embedded in a German market that has abandoned nuclear power and grown heavily reliant on renewables. On Tuesday, wholesale prices fell close to zero between noon and 3 p.m. as the sun shone through clear skies — only for the eclipse to send them soaring hours later. While most consumers and businesses buy electricity at fixed prices, the episode highlights the challenges grid operators face in balancing supply during overlapping weather and astronomical disruptions.insiderpaper