Simulation models underline the significance of wind power for achieving cost effective energy supply in Thuringia
Wind power as a key pillar of the future energy generation syste
Increasing costs associated with a reduced share of wind energy
Nordhausen, 12 December 2025 – A recent study by the Institute for Renewable Energy Technology (in.RET) at Nordhausen University of Applied Sciences, conducted as part of the state-funded research project ZO.RRO II, analyzes how different wind power expansion pathways affect the structure and total costs of the energy supply in Thuringia up to 2045. The analysis is based on a detailed energy system model that represents the regional energy supply on an hourly basis and takes into account both technical potentials and future energy demand.
The results show that the availability of wind power has a strong influence on both the costs and the composition of the energy system. In the model calculations, the wind power potential was varied, ranging from an expansion covering 2.2 percent of the state’s land area, as currently envisaged in regional planning, to a complete phase-out of wind turbines. While the first option represents the cost-optimal scenario, costs increase with every reduction in the available wind power capacity. Ultimately, a complete abandonment of wind power would raise the cost of supplying Thuringia with energy by 45 percent compared to the optimal scenario.
If an expansion limit for renewable energies aligned with regional demand is introduced, the cost-optimal solution requires wind power installations on around 2 percent of the state’s land area. If the wind power potential falls below 0.8 percent of the land area, Thuringia can no longer achieve a balanced self-supply of energy—in this case, Thuringia becomes a net energy importer.
Missing volumes of wind-generated electricity can only be compensated to a limited extent by expanding photovoltaic capacity: while photovoltaic systems primarily produce energy during the summer months, wind power generation shows the opposite seasonal pattern. A reduction in the available wind power potential in Thuringia therefore leads to a winter electricity gap that must be closed by importing comparatively expensive electricity. The model calculations indicate that the cost optimum is achieved with a wind-to-photovoltaic capacity ratio of 1:1.4. Deviating from this ratio to the detriment of wind power results in higher overall energy system costs.
„The results confirm that any discussion about technology neutrality necessarily requires cost transparency. Technologies can only be compared seriously if they come with a price tag,” says Prof. Dr.-Ing. Viktor Wesselak, project lead of ZO.RRO II at Nordhausen University of Applied Sciences.
The model calculations also take into account interactions with other energy sectors. For example, if sufficient amounts of wind-generated electricity are available, power-to-heat systems and local thermal storage can be used to supply district heating networks. Thuringia’s biomass potential is already being intensively utilized today and is therefore only available to a limited extent for further expansion in the heat supply sector. For existing biogas plants, the model indicates an advantage in converting them to biomethane production, as this contributes to meeting the demand for fuel gases that will still exist in 2045.
The methodology, assumptions, and results were first presented in early November at the 32nd Energy Symposium in Stralsund. The full paper, “Impact of the Share of Wind Power in the Energy Mix on the Overall Economic Costs of the Energy System – The Case of Thuringia,” is available here: www.hs-nordhausen.de.
The ZO.RRO II SME project, jointly led by Nordhausen University of Applied Sciences and the Thuringian Renewable Energy Network (ThEEN) e.V., is funded by the Free State of Thuringia through the Thuringian Ministry for the Environment, Energy, Nature Conservation and Forests.
The aim is to calculate realistic future scenarios for a climate-neutral energy supply for the entire Free State of Thuringia, as well as specifically for small and medium-sized enterprises (SMEs) in Thuringia’s industrial sector. Based on these pilot projects, valuable knowledge transfer to the Thuringian economy and beyond will take place by July 2026. The core of the work consists of digital tools such as energy system modeling, which support the pathway to climate neutrality. More information about the ZO.RRO II project is available online at www.zorro-thueringen.de.
Project funding provided by the Thuringian Ministry for the Environment, Energy and Nature Conservation.
