Material Recovery from Dutch Wind Energy

Abstract

The transition to a renewable electricity system requires more intensive material use, causing problem shifting in environmental impacts. To conserve resources for the future and mitigate environmental impact, circular economy principles are needed. This study analyses material flows in Dutch wind energy towards 2050 to identify the potential for material recovery. This reveals material demand, stock, secondary material supply and required recycling infrastructure within environmental and economic context. Material compositions, current stock and future installed capacity result in inflow, stock and outflow of materials in Dutch wind energy. Inflows or demand for materials is increasing rapidly due to strong expected growth in the near future (2023), additional inflows are required after 2030 for stock maintenance. Outflows fluctuate, partly due to an early peak in onshore decommissioning and late peak in offshore decommissioning caused by a more mature stock of onshore wind turbines and currently developing stock of offshore wind turbines. The outflow of scrap materials is used to determine secondary materials through various recycling routes. For steel, iron, aluminium and copper minor processing losses occur as materials oxidize or get lost to slag. Due to partial removal of monopiles, a hibernating stock is expected for structural steel that increases towards 0.5 Mt in 2050. Current steel and iron recycling results in dilution and therefore loss of function of valuable and critical alloying elements. Composite waste management in wind energy is a major challenge as closed-loop recycling of composites is not feasible. The cascading effect of material quality results in low-value materials, with varying potential demand. Repurposing of blade segments requires minimal processing and could be implemented at present, provided that there is enough demand for composite sheet and beam segments. Cement co-processing uses existing cement production infrastructure and could be implemented at present, with ample demand for cement clinker. Dutch wind energy could exclusively provide sufficient composite scrap material to run industrial-scale mechanical grinding after 2030 and pyrolysis facilities after 2040. Critical materials include vanadium in gear steel alloys, magnesium in cast iron and rare earth elements in permanent magnets. These critical materials are subject to high economic importance and supply risk. Secondary supply through recycling can mitigate this criticality. Vanadium in gearbox steel and magnesium in cast iron can be functionally recycled by selective collection within existing recycling infrastructure for specialty steels. It is estimated that with maximum recycling efforts, secondary supply of critical materials can meet up to ~15% of REE, ~30 of V and ~25% of Mg demand by 2050. Dutch wind energy will not provide sufficient scrap magnet material for an industrial size recycling facility dedicated to magnet or REE recovery before 2050.
By determining the potential for material recovery from Dutch wind energy, a timeline is created for potential implementation of domestic recycling and secondary material availability. This is a first step towards circularity goals in 2050 and is intended to provide a sense of scale and timing for material demand, secondary supply and required recycling infrastructure for Dutch wind energy.