High temperatures and severe drought in Europe this summer have affected hydro, nuclear and solar power generation. Statistics from Norwegian consulting firm Rystad Energy show that in the first seven months of this year, Europe's hydropower generation decreased by 20% compared with the same period last year, and nuclear power generation decreased by 12%.

High temperatures lead to increased evaporation in rivers, lakes and reservoirs, lowering water levels, and hydropower bearing the brunt. In Italy, for example, hydropower accounts for 20% of the country's total electricity production, but the country's hydropower production has plummeted by 40% in the past 12 months. Hydropower production in Spain also plunged by 44%.

Energy analyst Fabien Langningen said that although hydropower production fluctuates widely, the 40% drop is "very extreme", not only in local areas, but all European hydropower majors have not been spared.

Energy exporter Norway has warned that it may have to stop exporting energy to countries such as the UK if the country's reservoirs fail to recover.

Insufficient investment in hydropower infrastructure and aging transmission lines are also reasons for the decline in hydropower output, some hydropower industry experts say.

Eddie Ritchie, an expert at the International Hydropower Association, said: "We are going to have (power) problems this winter. This should be a wake-up call for us to invest more in infrastructure in the next few years."

The drought has also affected nuclear power, with France being particularly affected. Several nuclear power plants of EDF have cut production in recent days, because the water temperature in natural waters is currently high, affecting the water used for cooling reactors in nuclear power plants.

Sonia Senaviratner, a professor at ETH Zurich, explained that if the water level in the river is too low and the water temperature is too high, the cooling of the reactor can only be stopped, otherwise the discharged water will endanger the life in the river.

The French government on the 5th of this month instructed a crisis response working group to coordinate the work of various departments to deal with the drought. "This is the worst drought ever recorded in France," the French prime minister's office said in a statement.

High temperature weather is also not conducive to solar power generation, because photovoltaic power generation panels are "afraid of the sun", and high temperature will lead to power loss of power generation panels and shortened service life.

Kathryn Porter, a consultant at energy consultancy Watt-Logic, said that when temperatures exceed 25 degrees Celsius, the output of photovoltaic panels drops significantly, and "everything works worse when the temperature is high".