France's energy system faces a tight evening as low nuclear availability drives up power prices. The intraday price rose to €292 a megawatt-hour for 7 p.m. delivery on Epex Spot, while nuclear reactors operated at 67% capacity on Tuesday, down from 72% on Monday, per Bloomberg calculations from RTE data.

Electricite de France SA halted output at Flamanville 1 and Civaux 1 and extended halts at St Laurent 1, Chooz 1, and Chooz 2. Strike action at hydropower facilities is also affecting generation. Germany's intraday prices spiked to around €300 for the evening peak.

Europe's shift from a solar-dominated summer system to greater winter reliance on wind increases the importance of baseload nuclear plants in cushioning output swings.