Wind energy in the south: Systemic savings through avoided redispatch costs
The expansion of onshore wind energy continues to develop unevenly across regions. Recent EEG tender results show a continuous decrease in awarded bid prices, driven by sharply increasing competition. Despite larger auction volumes, the procedures are increasingly oversubscribed, supported by the significantly growing number of designated areas and faster approval processes. This dynamic reinforces the structural locational advantages of wind‑rich regions in northern Germany. As a result, there is growing concern that southern German projects, particularly in Baden‑Württemberg and Bavaria, will receive awards only rarely due to their higher bid prices, even though sufficient land potential fundamentally exists.
Although the EEG 2023 already includes the reference yield model (Referenzertragsmodell) as an instrument explicitly intended to account for regional differences in wind resources, practical experience shows that this compensation mechanism no longer delivers the originally intended effect under current market and auction conditions. In light of the upcoming revision of the EEG, the question arises whether adjustments are needed that also consider the systemic benefits of a more regionally balanced wind expansion, such as reductions in redispatch. An incentive system better tailored to today’s conditions could help correct regionally skewed expansion pathways and, in the long term, contribute to a more robust and economically efficient overall energy system.
Key Findings
1. The market tends toward a one‑sided northern expansion, shifting around 10 GW from the South into regions already strongly affected by redispatch.
Under current auction trends, hereinafter referred to as trend expansion scenario, only 2.85 GW would be installed in Baden‑Württemberg and 3.72 GW in Bavaria by 2030. In contrast, according to the current Grid Development Plan 2025’s regionalization approach, an expansion of 7.46 GW and 9.37 GW respectively is expected, hereinafter referred to as NEP‑based expansion. In total, roughly 10 GW of potential installed capacity would thus shift from Bavaria and Baden‑Württemberg to northern German regions (see Figure 1), which are already characterized today by high curtailment volumes. In line with § 13k EnWG, these areas are referred to as relief regions in this study.
2. More generation in the North results in around 9 TWh of additional curtailment.
Although the bid‑price‑driven scenario enables 13–17 TWh higher gross generation due to stronger expansion in the North, a large share of this additional production is lost through significantly intensified curtailment in the relief regions. In total, approximately 9 TWh is additionally curtailed.
3. Increased wind expansion in the South can save up to €1.8 billion in redispatch costs per year.
A more regionally balanced wind expansion leads to slightly lower total electricity generation but can overall provide substantial economic and system‑level advantages. By 2030, a stronger expansion of wind energy in the South, as envisioned in the NEP, could avoid up to €1.8 billion in additional annual redispatch costs.
Further Systemic Aspects for the Discussion
The methodology used deliberately follows a conservative approach and constitutes a simplification, as no full network simulations were conducted. Beyond redispatch needs and costs, several additional systemic aspects are relevant to the discussion.
A key factor is the context of planned grid expansion. Measures such as Ultranet, SuedLink, and SuedOstLink should be considered when evaluating regional expansion pathways, as realistic assessments of their impacts require network simulations to capture congestion situations, power flows, and transmission capacities adequately. Market‑related effects also play a role. Stronger expansion in the South can reduce cannibalization effects due to lower simultaneity of feed‑in, potentially resulting in higher market values and therefore lower market premiums. At the same time, southern German sites require higher remuneration levels within the reference yield model due to lower wind speeds. Consequently, despite potentially higher market values, overall higher market premiums may still be necessary. Moreover, an unbalanced, northern‑heavy expansion affects future demand for positive redispatch capacity, particularly from the grid reserve. These resources often have higher specific costs, placing an additional burden on congestion management.
Conclusion
Overall, the brief study demonstrates that the regional distribution of wind expansion has a significant impact on redispatch volumes and costs. Although neither grid expansion simulations nor a full energy system model were used in the analyses, the results provide an important technical impulse: A more regionally balanced expansion pathway with greater build‑out in southern Germany can lead to lower overall redispatch costs. This study therefore offers an initial technical basis for deeper and more comprehensive discussions on the further development of the EEG and the design of regionally differentiated incentive mechanisms.
