For their analysis, the researchers reconstructed the development of Germany’s wind turbine fleet since 1988 and modelled various scenarios for its future development up to 2050. Among other things, they examined the material requirements for concrete, steel, copper, aluminium, polymers and composite materials. The study makes it clear that the further expansion of wind energy is associated with a considerable demand for materials. At the same time, the results show that the specific design of repowering measures is crucial for resource efficiency. In particular, the reuse of foundations, infrastructure components and other plant parts can significantly reduce material requirements.
The study analyses material flows and resource efficiency in the wind energy sector. Against the backdrop of wind energy expansion targets, it examines how future expansion can be organised in a way that conserves resources as much as possible. In doing so, it provides a scientific basis for assessing material requirements and potential savings in relation to wind turbines.
“Our aim was to systematically examine the material requirements of different expansion and repowering pathways and to highlight potential for material savings,” emphasises Christoph Helbig, Professor of Ecological Resource Technology and co-author of the study. “The results show that reuse strategies can be an important lever for combining resource efficiency with expansion targets.” The recycling of the wind turbines after their use was not part of this assessment.
In public debate, reference is often made to the absolute quantities of materials required for the construction and refurbishment of wind turbines. The study confirms that wind turbines consist of significant quantities of various raw materials and that their expansion requires corresponding resources. However, the key scientific finding of the study does not lie solely in quantifying these material requirements. Rather, a key finding concerns the potential to reduce future resource consumption through appropriate repowering strategies. Repowering refers to the replacement of older wind turbines with modern, more powerful ones. In the repowering scenario, in which the foundations, towers, and parts of the wind farm infrastructure are reused, the demand for concrete for onshore wind expansion is reduced by 14%, steel by 10%, and copper by 7% compared to a repowering scenario without reuse. For German offshore wind farms, cumulative copper demand would fall by 11% in the repowering scenario with reuse of the infrastructure. The analysis shows that, in particular, approaches to reusing foundations and infrastructure components can enable substantial material savings.
The researchers view their work as a contribution to a fact-based assessment of resource issues in the energy sector. Material requirements, the availability of raw materials, reuse and the circular economy are becoming increasingly important as the energy system undergoes transformation. The study provides a quantitative basis for this and highlights the options available for reducing resource use in the wind energy sector.
The University of Bayreuth points out that no blanket conclusions for or against a particular energy technology can be drawn from the study’s findings. Rather, the study provides scientific insights into how material flows are developing and what options are available for improving resource efficiency.
