The total volume of measures taken for congestion management (including redispatching with operational and grid reserve power plants and countertrading) declined from 5,878 gigawatt hours (GWh) in the second quarter of 2025 to 5,263 GWh in the same quarter of 2026. Provisional total costs, meanwhile, recorded a small increase to €673mn from €659mn.

97% of renewable electricity generated successfully transported to final customers

The reductions and increases in feed-in from operational power plants (excluding countertrading) as part of the redispatching process amounted to around 4,189 GWh in Q2 2026 (Q2 2025: 4,602 GWh). Reductions in feed-in made up 3,095 GWh of the total (Q2 2025: 3,296 GWh), with redispatching measures involving renewable power plants contributing 2,102 GWh of that (Q2 2025: 2,325 GWh). The volume of redispatching with renewables was about 10% lower than in the same quarter of last year.

• The volume of redispatching measures affecting photovoltaic (PV) installations was about 4% down on Q2 2025 at 1,124 GWh from 1,171 GWh. However, this volume was nearly twice as much as in the second quarter of 2024 (607 GWh) and thus still at a high level.
• The redispatching volume for onshore wind installations fell from 550 GWh in Q2 2025 to 527 GWh in Q2 2026, largely due to the period being less windy than the same quarter of last year. As less wind power was being fed in, fewer curtailments of onshore wind installations were necessary.
• The volume of redispatching measures involving offshore wind installations was down on the previous year’s quarter too, by about 28% to 415 GWh (Q2 2025: 575 GWh). This was partly because of the less windy conditions but also because of the high feed-in from PV installations changing the congestion situation in the grid. High levels of solar generation can, in particular, lead to greater flows from east to west, which cannot be influenced significantly by curtailing offshore wind. In addition, the progress being made in expanding the network is helping to relieve existing areas of congestion.

The changed congestion situation is leading to a shift in the causes of redispatching measures. In the period under review, about 52% of the redispatch volume in renewables was caused by congestion in the distribution system, while 48% was attributed to congestion in the transmission system. It was the first quarter in which more of the redispatch volume was due to measures with causes in the distribution system than measures with causes in the transmission system. A trend in that direction had been emerging in recent quarters. 

In the same quarter of the previous year, the split had been 49% from the distribution system and 51% from the transmission system. By contrast, in the second quarter of 2024, 29% of the redispatch volume had been made up of measures caused by congestion in the distribution system and 71% by measures caused by congestion in the transmission system.

Overall, renewable energy curtailments amounted to 3% of the total amount of electricity generated by renewables. This means that 97% of the renewable energy produced was fed into the grid and used by final customers.

To balance out the reductions, feed-in from operational power plants was increased by a total of 1,093 GWh in Q2 2026 (Q2 2025: 1,306 GWh). In addition, feed-in from reserve power plants was increased by 479 GWh, made up of 283 GWh for activations and 196 GWh for test starts and test runs. In Q2 2025, the corresponding volumes were 252 GWh for activations and 86 GWh for test starts and test runs. The rise in test starts and test runs is down to various operational reasons at the reserve power plants, such as testing following inspections or longer downtimes.

If the test starts and test runs are not taken into account, the total increase to balance out the reductions amounted to 1,376 GWh, around 12% below the previous year’s figure (Q2 2025: 1,558 GWh). There was less use of reserve plants because there was a lower volume of redispatch overall compared to the previous year.

Reductions in the distribution system countered this trend and increased considerably. As distribution system operators cannot balance the reductions themselves, the balance responsible parties carry out the balancing. The volumes necessary for this are not included in the increases shown here.

The volume of the countertrading measures taken fell by 36% from 937 GWh in the second quarter of 2025 to around 595 GWh in the same quarter of 2026. The reasons for the drop are similar to those for the decline in curtailment of offshore wind: less wind, changed network flows caused by high levels of solar generation and the ongoing expansion of the grid. These factors led to less need for countertrading measures overall.

Costs of congestion management rose slightly despite decline in volume

The total costs for congestion management measures in the second quarter of 2026 were provisionally put at around €673mn (Q2 2025: €659mn), a slight rise despite the lower volume. The higher costs of contracting reserve power plants drove the increase. The total costs of congestion management are broken down as follows:

The provisional costs for redispatching measures using conventional operational power plants in the second quarter of 2026 were €199mn, representing an 11% rise compared with the same quarter of 2025 (€179mn). Higher fuel and wholesale prices were the primary reasons.
In Q2 2026, the financial compensation paid to operators of curtailed renewable energy installations fell by 21% to around €126mn (Q2 2025: €159mn).

When feed-in from direct-selling renewable energy installations is reduced, plant operators are treated economically as if the intervention measure had not taken place. The network operator credits the reduced volume of electricity to the balancing group of the installation operators and/or their direct sellers. This enables the plant operator to actually complete its commercial transaction and receive the same market revenue as agreed with the direct seller. The plant operator also receives the market premium from the network operator, which is the financial support for direct selling under the Renewable Energy Sources Act (EEG). The market premium is the difference between a certain set price of the installation (equal to the renewable energy installation’s primary revenue need) and the monthly average price for electricity on the exchange.

The average wholesale prices in Q2 2026 were up 36% on the same quarter of last year (Q2 2026: €95/MWh; Q2 2025: €70/MWh). Rising wholesale prices lead to a lower market premium and thus less financial compensation. The lower compensation is thus caused by the higher wholesale prices as well as by the lower curtailment volume of renewable energy installations.

The provisional costs of reserving the grid reserve plant capacity plus costs not dependent on the use of the reserve in the second quarter of 2026 totalled €256mn (Q2 2025: €219mn). At about €81mn, the costs of deploying the grid reserve were nearly the same as in Q2 2025 (€82mn). The total costs for the grid reserve were about €337mn.

While the deployment costs were almost unchanged, the reservation costs were up 17%. The higher costs may be attributed to various factors, including costs related to the inclusion of new plants in the grid reserve and higher overheads, staffing and maintenance costs.

The net costs for countertrading measures in the second quarter of 2026 were about €10mn, corresponding to a decrease of 47% despite the rise in wholesale prices (Q2 2025: €19mn). The main reason for the decline is the lower volume of countertrading measures.