German day-ahead power printed minus EUR 15.01/MWh in its lowest quarter-hour on Saturday 25 July, and France minus EUR 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 EUR 100 on an already negative spark . 1
The daily mean tells a different story from the extremes. Germany still averaged EUR 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 EUR 85.11/MWh. 3 This desk's EUR 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.
