In the second quarter of 2025, redispatching measures involving renewables amounted to 2,299 gigawatt hours (GWh), with measures due to causes in the distribution system accounting for 1,121 GWh (49%) and measures due to causes in the transmission system accounting for the remaining 1,178 GWh (51%).

By comparison, the total volume of renewable curtailment measures in the second quarter of 2024 was 2,101 GWh, with 29% due to causes at distribution level and 71% at transmission level. The total volume in the second quarter of 2023 was 1,838 GWh, with 23% and 77% due to causes at distribution and transmission level respectively.

The increase in the volume of measures due to causes in the distribution system is accompanied by a decrease in the volume due to causes in the transmission system.

However, this trend is not visible in the first quarter (winter months) of the years.

This suggests that the shift may be due to the growth in solar capacity and the inability of the networks to fully accommodate this growth.

Redispatching due to causes in the transmission system

In the second quarter of 2025 the total volume of redispatching measures due to causes at transmission level was 1,178 GWh. The curtailment measures taken by transmission system operators (TSOs) in their own networks accounted for 677 GWh (57%) of this volume. In the second quarter of 2024 such measures accounted for 988 GWh (66%) and in the second quarter of 2023 for 1,036 GWh (73%).

In the second quarter of 2025 the redispatching measures due to causes at transmission level and taken by distribution system operators (DSOs) amounted to 465 GWh (43%). By comparison, such measures amounted to 504 GWh (34%) in the second quarter of 2024 and 388 GWh (27%) in the second quarter of 2023.

The figures show a trend where the volume of redispatching measures with renewables due to causes in the transmission system decreases in the summer months. At the same time, in the second quarter of the year a larger proportion of the measures due to causes at transmission level are taken by DSOs.

Offshore wind accounted for the largest proportion of renewable curtailment measures due to causes at transmission level and taken by TSOs. However, there was a continual decrease in the volume of redispatching measures involving offshore wind in the period under review, from 1,003 GWh in the second quarter of 2023 to 913 GWh in the second quarter of 2024 and to 575 GWh in the second quarter of 2025. There was also a decrease in the volume of curtailment measures involving onshore wind, from 350 GWh in 2024 to 225 GWh in 2025. Reductions in the distribution system accounted for 79% of the curtailed energy.

This is accompanied by a continuous increase in redispatching measures involving solar installations in distribution networks but due to causes at transmission level: from 100 GWh in the second quarter of 2023 to 203 GWh in the second quarter of 2024 and to 281 GWh in the second quarter of 2025.

Redispatching due to causes in the distribution system

In the second quarter of 2025 the total volume of redispatching measures due to causes at distribution level and taken by DSOs was 1,121 GWh. This represents a year-on-year increase of 84% and an increase of as much as 170% on the second quarter of 2023 (Q2 2024: 608 GWh; Q2 2023: 414 GWh).

In the second quarter of 2025 solar accounted for around 802 GWh (72%) of total curtailments and onshore wind for 301 GWh (27%), with the remainder involving other types of renewable installations.
While there was a relatively moderate increase in onshore wind curtailments (Q2 2025: 301 GWh; Q2 2024: 223 GWh; Q2 2023: 170 GWh), there was a much larger increase in curtailments in solar feed-in. The volume of solar curtailments in the second quarter of 2025 was 112% higher than in the second quarter of 2024 and as much as 237% higher than in the second quarter of 2023 (Q2 2024: 378 GWh; Q2 2023: 238 GWh).

This development is reflected in the continuous increase in solar’s share in curtailments due to network congestion in the distribution system, with 57% in the second quarter of 2023, 62% in the second quarter of 2024 and 72% in the second quarter of 2025.

A breakdown of curtailments at distribution level across the federal states shows that Bavaria had by far the largest volume in the second quarter of 2025, with 614 GWh, followed by Brandenburg with 167 GWh. This means that Bavaria accounted for about 55% of all curtailments with renewables. This represents a year-on-year increase of 90% and an increase of as much as 247% on the second quarter of 2023. This development is in proportion to the large increase in solar curtailments.

Possible reasons for this development

Increase in solar generation

In the second quarter of 2025 solar made up the largest share of all energy sources in Germany’s electricity generation mix (29.0 TWh), clearly surpassing its own previous quarterly high of 24 TWh from the second quarter of 2024.
There is a clear correlation between the volume of curtailments in solar energy and the volume of solar energy actually generated.

Besides the continuous growth in solar capacity (2023: 63 GW; 2024: 77 GW (+22%); 2025: 86 GW (+12%)), the unusually sunny weather was the main reason for the rise.

Figures from the Bundesnetzagentur’s core energy market data register show that nearly all solar installations in Germany are connected to the distribution system; the proportion of solar installations in the transmission system is well below 1%. The prolonged growth in capacity means more feed-in at distribution level, leading to more frequent congestion in the distribution networks. This indicates that the expansion of the distribution networks is not yet keeping pace with the continuous increase in the proportion of electricity fed in by solar installations.

Main causes of redispatching shift from transmission to distribution level in the summer months

According to the TSOs, the large increase in solar generation in the second quarter of 2025 combined with less windy conditions led to a noticeable change in the congestion situation in the electricity grid.

The high level of solar feed-in caused greater east-west flows, which are little affected by offshore wind farms. At the same time, lower wind levels meant that the typical north-south flows were not as strong. There was consequently a reduction in the need for redispatching in the transmission system overall and in the technical suitability of offshore wind plants for relieving specific cases of congestion. As a result, the volume of redispatching measures involving offshore wind in the second quarter of 2025 was 37% lower than in 2024, at 575 GHz.

As offshore wind plants are only connected to the transmission system, there was also a decrease in the volume of the TSOs’ redispatching measures with renewables. This was accompanied by an increase in the proportion of redispatching measures due to causes in the distribution system.