The day-ahead electricity spread between Italy and France reached €153/MWh on Sunday 26 April, with the French zone clearing at EUR -43.73/MWh and the Italian zone at €109.38/MWh1. Germany cleared at €1.49/MWh on strong wind and solar output.
Negative power prices in the French zone alongside three-figure positive prices in Italy on the same delivery day says the Franco-Italian interconnector was constrained on the limit on Sunday. The day-ahead market is the European power market that clears for next-day delivery on national zonal coupling; spreads of this magnitude across an HVDC link are normally the indicator that one zone has surplus renewable output the link cannot evacuate, while the receiving zone runs gas peakers to cover residual demand.
The trade implication is that Italian power-sector gas demand on a renewable-rich Sunday is still bound by the interconnector envelope rather than by the TTF benchmark. Italian gas storage sits at 48.15% fill, the leading large EU storage market; even with a comfortable inventory position, day-ahead power separates from the gas curve when the link binds. For procurement desks pricing Italian forward power against TTF spot, the €153/MWh spread is a constraint not in the curve and not in recent ENTSOG or ACER coverage. The same constraint matters for EDF's French nuclear export envelope through summer 2026, since France clearing negative on a Sunday means renewables and nuclear together exceed both domestic demand and the link's evacuation capacity. Southern European industrial users pay a constraint premium that the gas-side balance does not show, and the same dynamic is what gives Bruegel's Spain evidence credibility: when renewables clear the local zonal price, the interconnector becomes the binding constraint, not the marginal gas plant.
