Europe’s hydropower nears ‘all-time-low’ as summer drought worsens. Is gas the only backup?
Hydropower flow in the Alpine region is “close to an all-time low” amid Europe’s worsening summer drought. Following back-to-back heatwaves – fuelled by human-caused climate change – and scant rainfall, much...
Hydropower flow in the Alpine region is “close to an all-time low” amid Europe’s worsening summer drought.
Following back-to-back heatwaves – fuelled by human-caused climate change – and scant rainfall, much of the continent has been left parched. This has increased the likelihood of deadly wildfires that have ravaged countries like France, Spain, Greece and Türkiye, and forced hundreds of thousands to be evacuated.
Fears of food shortages have also hit, as farmers warn that billions of euros of crops have been destroyed in the extreme heat.
According to the Combined Drought Indicator (CDI), in mid-July, alert drought conditions persisted in parts of Ukraine, Belarus, Poland, emerged in the northeastern Iberian Peninsula, and worsened in the southern UK, northern Italy and central Europe – from France and southern Germany to Hungary and Romania, also affecting Switzerland, Austria, Czechia, Slovakia and Serbia.
The dry spell has also impacted Europe’s clean energy mix, as record-low water levels in the Danube river mean that Hungary will power down its Paks nuclear plant, which provides almost half of the country’s electricity, for the first time in nearly half a century.
How Europe’s drought is impacting hydropower
According to energy intelligence firm Montel, inflows to reservoirs and run-of-river hydropower plants in Austria and Switzerland were nearly 50 per cent below average in July.
Total hydro production for Austria in July was only 51 per cent of normal levels (compared against the last 15 years) due to low rainfall, Montel adds. Similarly, Switzerland saw 48 per cent of normal production, while Germany (63 per cent) and France (68 per cent) also suffered.
Hydropower is the second largest renewable electricity source in the EU, providing 28 per cent of the bloc’s electricity in the first quarter of 2026. This is more than solar (17.3 per cent), combustible renewable fuels (9.4 per cent) and geothermal and other energy sources (0.4 per cent).
“We are simply missing one-third of the water volume that our hydropower plants would normally process,” says Michael Strugl, CEO of Austria’s leading energy company Verbund.
Montel’s senior hydrology analyst Eylert warns that Alpine countries will have to wait until September before any signs of improvement start to show, as weather outlooks forecast several more weeks of hot and dry conditions.
Can Europe cope without hydropower?
Many countries, such as Portugal and Austria, are heavily reliant on hydropower – meaning significant drops in output can push a country back onto polluting fossil fuels.
For example, gas generation in the EU rose by eight per cent last year (compared to 2024). Energy think-tank Ember says this is largely due to reduced hydro output, as weather conditions triggered a 12 per cent drop in annual production.
However, the same weather conditions (which also caused wind power to fall by two per cent) boosted solar generation.
This meant that in 2025, solar generated more EU power than ever before, growing by more than 20 per cent. It highlights the need for countries to diversify their renewable energy mix to survive climate-fuelled extreme weather.
Hydropower also works well with inflexible forms of clean energy such as wind and solar, effectively acting like on-demand batteries which can be ramped-up when electricity consumption increases or run at low output in off-peak hours.
Instead of clean energy from the sun and wind being wasted due to grid constraints, experts say Europe could use ‘hybridisation’ – which combines technologies like wind, solar and storage behind a single grid connection. Think of it like the three sources sharing the same ‘plug’ into the electricity grid.
“By adding wind or solar at the same connection point as a hydropower plant, developers can get online faster and operators can use grid infrastructure more efficiently – on average doubling utilisation – while staying within export limits,” says Elisabeth Cremona, energy infrastructures lead at Ember.
A recent Ember report found that across Austria, Bulgaria, France, Italy, Portugal, Romania and Spain (the EU’s major hydropower markets) hybridisation could integrate 18 per cent of the new renewables expected by 2030 without requiring additional grid capacity.
