Potential for Reducing Redispatch through Wind Energy in Southern Germany

Motivation

Germany faces the challenge of further supporting the expansion of wind energy, integrating it more effectively into the energy system, and reducing regional imbalances. Current EEG auction results from 2025 show that the rounds are heavily oversubscribed, leading to decreasing awarded bid prices [1]. As a result, there is a risk that the EEG reference yield model (Referenzertragsmodell) [2] may no longer be sufficient under current market conditions to ensure that wind energy projects in southern Germany can continue to receive support at the required scale. In particular, Bavaria and Baden‑Württemberg could see large wind energy potentials remain unused, despite the availability of extensive designated areas [3].

At the same time, redispatch costs remain high, as strong wind feed-in in the north regularly leads to grid congestion. This results in significant curtailment volumes in the north and positive redispatch measures in the south. With this current situation, the question arises whether an increased expansion of wind energy in southern Germany could provide system-level benefits, including potential reductions in redispatch costs.

Project Objectives

The aim of the study is to systematically quantify the impacts of two different regional expansion pathways for onshore wind energy in Germany by 2030: a trend-based expansion pathway (with more development in the north) and a grid-oriented expansion pathway (with a more regionally balanced distribution of capacity additions).

The additional redispatch requirements and the associated costs of both pathways are compared. Based on this comparison, the study assesses whether a stronger expansion of wind energy in southern Germany can provide system-level benefits.

Methodology

For the analysis, the status quo and all relevant data sources were comprehensively prepared and evaluated for the year 2025. Subsequently, the nationwide expansion target for 2030 for wind onshore (115 GW according to EEG‑2023) was set. Based on this, two regionalization approaches were used to derive the wind onshore energy expansion in Germany for the year 2030:

• Bid-price-based scenario: Trend-based expansion following current EEG auction dynamics; prioritization of wind expansion based on turbine-specific bid price calculations, resulting in a stronger focus on northern Germany.
• NEP-based scenario: Grid-oriented expansion pathway expected by transmission system operators; prioritization of wind expansion based on turbine-specific categorization and expected development stages according to the German Grid Development Plan, resulting in a more regionally balanced distribution.

Once both expansion pathways were defined, additional redispatch volumes and redispatch costs were calculated. These calculations are based on modelled generation time series and derived curtailment time series. The applied methodology is intentionally conservative and represents a simplification, as no power grid simulations were performed. The results of both scenarios are then compared to analyse the additional redispatch costs. All calculations were carried out for two meteorologically different weather years (2023 and 2024). Figure 1 illustrates the methodological approach.

Within the framework of the study, the FfE conducted the following tasks:

• Preparation and plausibility checks of MaStR data (existing & planned turbines)
• Modelling of future wind farm configurations (WiSTL tool)
• Modelling of hourly generation time series (ERA5 weather data + turbine power curves)
• Derivation of regional curtailment profiles for relief regions and the remaining northern region
• Quantification of redispatch volumes and costs for both scenarios
• Assessment of system-level effects and economic implications

Results

The central result of the short study is that a regionally balanced expansion pathway with significantly more wind energy development in southern Germany can save up to €1.9 billion in redispatch costs per year, compared to a trend-based expansion pathway that concentrates mainly in northern Germany.

The results should be interpreted in the context of the conservatively applied methodology. Current auction trends increasingly favour the bid‑price‑based scenario, which leads to higher redispatch costs. A stronger expansion in the south, as assumed in the grid‑oriented expansion pathway, can therefore provide system-level advantages and contribute to reducing congestion management requirements in the long term.

Literature

[1] Monitor EEG-Auktionen Wind | Goal100. In https://goal100.org/monitor/auktionen. (Abruf am 2026-2-18); Berlin: ProjectTogether gGmbH, 2026.

[2] Gesetz für den Ausbau erneuerbarer Energien (Erneuerbare- Energien-Gesetz – EEG 2023) (EEG 2023). Ausgefertigt am 2014-07-21, Version vom 2023-07-26; Berlin: Bundesministerium der Justiz, 2023

[3] Planungsstand Windenergiegebiete. In https://www.fachagentur-wind-solar.de/veroeffentlichungen/interaktive-karten/planungsstand-windenergiegebiete#c1497. (Abruf am 2026-2-18); Berlin: Fachagentur Wind und Solar e. V., 2026.