French day-ahead cleared €41.13/MWh on Sunday 26 July against Germany's €84.22, a French discount of €43.09. On 20 July the same discount was €4.06.1 France exported 15.21 GW net that day, its hardest export day of the week.2
This desk's own WATCH FOR asked whether the spread would re-widen once the heat broke and French nuclear reasserted its cost advantage. It re-widened, and we named the wrong driver. French nuclear output did not move: 39.82 GW on Thursday 23 July, 40.14 GW on Friday the 24th, 39.07 GW on the Sunday the discount hit its widest.3 EDF's slipped restart schedule contributed nothing to the move. A Bugey 3 restart reported on 18 July remains unconfirmed by this desk, and it is a separate matter from the reactors 4 and 5 thermal derogation that expired on 20 July.4
Demand and weather produced the discount instead. French load fell from 44.97 GW on Friday to 38.34 GW on Sunday, the weekend trough, while French onshore wind more than doubled from 2.76 GW to 5.93 GW.5 A flat nuclear stack into a shrinking domestic load has to go somewhere, and it went across the interconnectors until the export capacity ran out.
Anyone long France against Germany on a nuclear thesis was right about the direction and wrong about the mechanism, which is the more expensive way to be right. The position survives exactly as long as the mechanism holds, and this one is a Sunday and a wind field, both of which reverse on Monday. Through the summer the FR-DE spread answers to German wind and weekend load, not to EDF's availability calendar; the nuclear-availability regime returns in winter, when French electric heating puts French load rather than German supply in charge of the difference.
