Low river levels cut nuclear output in Hungary and Romania

Record low water levels on European rivers are forcing nuclear output reductions in Hungary and Romania, Reuters reported on 30 July. Reactor cooling constraints are the direct mechanism: when river temperatures rise and flow volumes fall, operators must reduce thermal discharge to stay within environmental limits, cutting generation output.

The squeeze is not isolated to nuclear. Reuters also reported on 31 July that shrinking rivers across Europe are simultaneously curtailing hydropower, disrupting inland freight, and dragging on company earnings. Enel's H1 results, published the same day, illustrate the hydro pressure in Italy. Even so, the company recorded a 3% rise in core earnings, absorbing the hydro shortfall through other generation.

Against that thermal and hydro stress, the UK zone logged a structural milestone: renewables delivered 52% of electricity in 2025, according to government statistics cited by Renews.biz. It is the first year clean energy has held a majority of the UK generation mix on an annual basis.