A rare solar eclipse next week is set to pile pressure on Europe’s “tight” power system. Heatwaves have already forced nuclear and coal plants to switch off across the continent, while low water levels curtail hydropower stations. High temperatures have reduced river levels needed to cool plants in countries including France, Italy, and Poland, forcing several to rely on imports.

In Norway, hydropower reservoirs have reached their lowest levels in 30 years. The upcoming total eclipse in northern Spain and Portugal could reduce Spanish solar power by up to 5GW, equivalent to 13 per cent of maximum demand for a typical August Wednesday.

ENTSO-E expects a loss of 9.7 gigawatts of power production across Europe during the eclipse's strongest point. While grid operators are standing by to balance the system, the combination of extreme heat and the eclipse creates a significant challenge for European energy security.