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Autonomous Systems: Land & Sea
13JUN

Germany and France print sub-zero hours

2 min read
11:07UTC

German day-ahead printed minus €15.01/MWh in its lowest quarter-hour on Saturday 25 July, France minus €11.32, the first sub-zero prints of the window.

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TechnologyAssessed
Key takeaway

Negative quarter-hours arrived while the daily mean held near €90, a within-day shape problem.

German day-ahead power printed minus €15.01/MWh in its lowest quarter-hour on Saturday 25 July, and France minus €11.32, the first sub-zero prints of this window after a hard zero floor earlier in the week, when German day-ahead was still clearing near €100 on an already negative spark.⁠1

The daily mean tells a different story from the extremes. Germany still averaged €89.90/MWh that day, because 18.86 GW of solar met a Saturday load of 44.4 GW.⁠2 Midday oversupply drove a handful of quarter-hours below zero while the evening ramp kept the average up. Anyone hedged on daily averages saw an unremarkable summer weekend; anyone dispatching against quarter-hourly prices saw hours they had to pay to generate into.

A secondary tracker put Saturday's German day-ahead at €85.11/MWh.⁠3 This desk's €89.90 averages every quarter-hourly print of that day, published by SMARD under Bundesnetzagentur licence. The two figures measure different things and both can be right, which is worth knowing before anyone reconciles a position against the wrong series.

Deep Analysis

In plain English

For a few fifteen-minute periods on Saturday, both Germany and France were briefly paid to take electricity rather than paying for it, the first time either market had gone below zero in this run. That sounds dramatic, but it only happened for a handful of quarter-hours; across the whole day, average prices in both countries stayed well above zero. It happens because some power stations, like nuclear reactors, cannot simply switch off for fifteen minutes when there is a brief surplus, so the price goes negative instead to persuade someone to use the extra power.

Deep Analysis
Root Causes

A negative quarter-hour does not mean supply exceeded demand across the whole day, only that inflexible generation, must-run thermal plant, nuclear baseload and subsidised renewables that keep running regardless of price, could not be curtailed fast enough to avoid a brief oversupply window; Germany's €89.90 daily mean on the same day shows the problem was confined to specific quarter-hours rather than the day as a whole.

The structural driver is the mismatch between fifteen-minute price granularity and generation that cannot ramp on that timescale, which is why the two negative quarter-hours arrived on the softest-demand day of the week rather than the highest-wind day.

What could happen next?
  • Meaning

    The first sub-zero quarter-hours of the window are a granular oversupply signal, not evidence that either market's daily price level has broken down.

Sources:SMARD / Bundesnetzagentur via Fraunhofer ISE energy-charts·SMARD / Bundesnetzagentur via Fraunhofer ISE energy-charts
Mentions:Germany →France →SMARD →Spain →Bundesnetzagentur →
First Reported In

Update #30 · Wind, not peace, sank the German spark

SMARD / Bundesnetzagentur via Fraunhofer ISE energy-charts· 27 Jul 2026
Read original →
Causes and effects
This Event
Germany and France print sub-zero hours
Negative quarter-hours alongside a daily mean near €90 make this a shape problem inside the day, not a collapse in the level.
Led to
Same wind, two prices: solar sets gap
The first sub-zero quarter-hour prices of 25 July contrast with the EUR 187.30 night-time peak of 31 July on similar wind levels, isolating solar as the swing variable.
Occurred 31 Jul 2026
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Written with AI from Lowdown's published reporting. Not individually reviewed by an editor. Editorial standards.