German day-ahead reached €187.30/MWh at 05:00 UTC on Friday 31 July, with onshore and offshore wind at 3.4 GW1. At 10:15 UTC on Wednesday 29 July, wind sat at the same 3.4 GW and the price printed €0.00 to minus €0.06/MWh. Two prints, one wind level, and roughly €187 between them.
Solar output separates the two prints. Germany has installed enough solar capacity that around midday in July it covers most of the load left over once wind, nuclear imports and must-run plant are counted. That leftover is residual load: the slice of demand the market has to price by dispatching something dispatchable, which in Germany means a gas plant. At 10:15 there was almost no residual load to price. At 05:00 there was, and no solar to meet it.
This desk asked last week whether German power would snap back above €110 the next time wind fell toward 3 GW with TTF near €58. It did, by a wide margin. But we wrote the mechanism as wind alone, and that was wrong in a way the 29 July control print makes plain. The snapback is a night-time event, worth roughly a fifth of the daily hours, not a whole-day repricing. The negative quarter-hours France and Germany both posted on 25 July and the €187.30 print of six days later sit on nearly identical wind, and only the solar leg separates them.
The correction matters for anyone reading a wind forecast as a price forecast. Germany cleared €195/MWh on 30 June on the year's lowest wind week, but that episode combined weak wind with a heat surge lifting demand into the afternoon. As solar output falls through September and October, the hours when wind alone determines residual load widen from a pre-dawn block toward whole days, which is when a low-wind forecast starts to mean what this desk previously implied it already meant.
