Drought corridor cuts hydro output a fifth below norm, squeezes Danube nuclear

A drought corridor stretching from the Rhine delta to the lower Danube suppressed hydropower output by roughly one-fifth below recent norms across April–July 2026, according to pv magazine analysis of river-flow, generation, and price data. The worst-hit systems saw output fall by one-third to one-half.

Nuclear capacity along the Danube compounded the picture. River flows dropped to their lowest levels in seven years, forcing output cuts at plants that rely on river water for cooling. Romania's reactors faced persistent concerns over Danube water-level forecasts as of 10 August, per Reuters. Hungary's Paks plant began restoring one turbine on 10 August after a partial Danube recovery, following a period in which Hungarians were asked to curb power use during the acute crunch.

Gas-fired generation, cross-border imports, and above-average rainfall in Iberia absorbed most of the shortfall, per pv magazine. The offset came at a cost: prices rose steadily through the period. With Romania's nuclear outlook still uncertain and the Rhine-Danube corridor yet to fully rehydrate, supply-side pressure on Central and Eastern European zones is not resolved.