France cleared €123.50/MWh on 30 June while Germany's all-thermal stack cleared far above it, leaving a France-Germany day-ahead spread of €71.50 with Germany the dearer leg 1. Going into the heat, desks had watched whether river-temperature curtailment of French nuclear would flip that spread and make France the expensive side. It held the other way.
France runs Europe's largest nuclear fleet, which usually keeps its wholesale power below Germany's gas-and-coal pricing. Heat threatened that edge: warm rivers limit the cooling water reactors can return, forcing operators to throttle. Even so, €71.50 sits below the series records of €93.68 on 3 June and €96.20 on 8 June , so the gap widened without breaking new ground.
France stayed cheaper even as EDF (Électricité de France, the state nuclear utility) deepened curtailments to 12% of the fleet on river-cooling limits, taking Bugey 3 (910 MW) offline and throttling Golfech and Nogent 2 . The floor held because curtailment removes volume, not the low-cost baseload that sets the French price. The trend that reset France as the cheaper leg on 22 June carried through ; the spread inverts only when curtailment strips out enough baseload to push gas to the margin in France too, which 12% of the fleet did not reach.
