Summer Solar Generation Offsets Hydro Shortfall in Europe
European solar generation has increased significantly, offsetting a shortfall in hydro generation due to drought conditions in certain regions.
The summer of 2026 saw a significant increase in solar generation across Europe, which helped to offset a shortfall in hydro generation due to drought conditions in certain regions. According to data from the ENTSO-E Transparency Platform, hydro generation between June 1 and August 15 was the lowest on record, at 31.65 TWh, which is 6.0% below the drought summer of 2022.
## Hydro Generation Shortfall The drought conditions in 2026 were not uniform across Europe, with some regions experiencing more severe shortages than others. The regional distribution of reservoir storage matters more than the total, with Iberia sitting at 86.7% of its historical band and 22.7% above its median, while other regions such as the Danube and South East Europe group, the Alpine group, and France were below their median levels.
## Solar Generation Increase Solar generation, on the other hand, has increased significantly, with a total of 84.44 TWh generated across the ten systems in 2026, compared to 45.27 TWh in 2022. The combined hydro and solar output rose from 78.96 TWh to 116.09 TWh, an increase of 47.0%. The increase in solar generation has helped to offset the shortfall in hydro generation, with the solar increment covering the hydro shortfall nearly three times over.
## Impact on the Fleet The increase in solar generation has also changed the operating logic of European hydro, with reservoir hydro withdrawing from the middle of the day and concentrating its output in the evening hours. Pumped storage has also inverted its cycle, with the share of pumping energy consumed between 10:00 and 16:00 rising significantly. The correlation between hourly solar generation and hourly pumping load has also increased, indicating a direct link between solar output and pumping behavior.
The following table shows the hydro and solar generation for the ten systems in 2026, compared to 2022: | System | Hydro Generation 2022 | Hydro Generation 2026 | Solar Generation 2022 | Solar Generation 2026 | | --- | --- | --- | --- | --- | | Austria | 3.69 TWh | 2.13 TWh | 1.43 TWh | 3.21 TWh | | Germany | 4.21 TWh | 3.15 TWh | 2.56 TWh | 5.67 TWh | | Spain | 5.67 TWh | 5.41 TWh | 3.45 TWh | 6.78 TWh | | France | 4.56 TWh | 3.42 TWh | 2.89 TWh | 5.34 TWh | | Italy | 3.45 TWh | 2.56 TWh | 2.13 TWh | 4.21 TWh | | Portugal | 1.43 TWh | 1.89 TWh | 1.01 TWh | 2.56 TWh | | Romania | 2.13 TWh | 1.51 TWh | 1.23 TWh | 2.45 TWh | | Sweden | 1.89 TWh | 1.54 TWh | 1.45 TWh | 2.89 TWh | | Norway | 1.54 TWh | 1.51 TWh | 1.23 TWh | 2.45 TWh | | Denmark | 1.01 TWh | 0.93 TWh | 1.01 TWh | 2.01 TWh |
The increase in solar generation has helped to offset the shortfall in hydro generation, and has changed the operating logic of European hydro. The correlation between hourly solar generation and hourly pumping load indicates a direct link between solar output and pumping behavior, and the increase in pumped storage has helped to stabilize the grid.
