Demand for rare earth permanent magnets (REPMs) has grown drastically the past decades and is expected to increase further due to their use in electronics, electric vehicles and wind turbines. Rare earth supply challenges have increased the urgency to recycle End-of-Life (EoL) REPMs. This paper examined the development of global EoL REPM recycling by applying the Technological Innovation Systems (TIS) framework, assessing temporal development and dynamics between different aspects of the system. The analysis showed an acceleration of recycling innovation activities since 2013, evidenced by e.g. research and development initiatives, (commercial) pilot plants and media and policy attention. Activities were identified globally, with regional concentration of some functions. Innovation in EoL REPM recycling is mainly driven by policies and positive expectations, while entrepreneurial activities also contribute. The EoL REPM recycling TIS holds potential for further growth, if sufficient supplies of recyclable material are secured and a demand for recycled magnets is created. These goals can be achieved by developing the capacity to handle a diversity of waste products, by making recycling cost-effective, or by finding other marketing approaches for recycled magnets. This would enable the emergence of an independent market. Together with other circular economy solutions, EoL REPM recycling can contribute to a more sustainable and resilient magnet supply.

Joey Nijnens holds a Master's degree in industrial ecology from Delft Technical University and Leiden University, as well as a Master's degree in supply chain management from Groningen University. He is employed at Monitor Deloitte as a strategy consultant, the strategy practice of Deloitte Consulting in the Netherlands, where he focuses on energy transition strategy and circular economy. Over the past years, his academic pursuits have centered around critical raw material supply, clean energy production dynamics, and clean energy supply chains. In his current role, he actively contributes to shaping national energy transition strategies and advancing clean energy investments. Paul Behrens (UK) is an author and associate professor at Leiden University. His research and writing on climate, energy, and food has appeared in outlets such as the BBC, Thomson Reuters, Politico, Nature Sustainability, Nature Energy, PNAS, Nature Food, and Nature Communications. His popular science book, “The Best of Times, The Worst of Times: Futures from the Frontiers of Climate Science” (Indigo Press, 2021) describes humanity's current trajectory and possible futures in paired chapters of pessimism and hope. Paul won International Champion in the Frontiers Planet Prize and the Falling Walls Prize in 2023. Oscar Kraan is a senior manager at Monitor Deloitte, the strategy practice of Deloitte Consulting in the Netherlands. He has more than 10 years of experience supporting governments and companies in the energy sector navigate the future of energy. Since 2018, Oscar has been part of Deloitte, where he focuses on developing decarbonization strategies and supporting the development of the hydrogen market. He co-leads Deloitte's Global Hydrogen Center of Excellence and the Future of Energy practice within Deloitte. In his work at Deloitte, he continues to be involved in scientific research around energy system integration, wherein he combines scientific insights with policy and business challenges. Before Deloitte, Oscar obtained his PhD on the topic of energy transition scenarios, wherein he applied agent-based modeling to energy and electricity system modeling. Before and during his PhD, Oscar worked 6 years with Shell's Scenario Team and Shell's New Energies Strategy Team. Benjamin Sprecher is an assistant professor of circular product design at the Delft Technical University. His main research interests are sustainable design, quantification of environmental impacts, and industrial ecology. His current work explores how quantification of environmental impacts can inform sustainable and circular design and how decisions at the product design level relate to system-level concepts such as circular economy. His PhD and postdoc were focused on critical raw materials and supply chain resilience, and he remains working on these topics, as well. René Kleijn is a professor of resilient resource supply at Leiden University in the Netherlands. He serves as the department head of the industrial ecology group at Leiden University and the scientific lead of the Circular Industries Hub at the Leiden-Delft-Erasmus Centre for Sustainability. His research primarily centers on sustainability matters, employing quantitative methods like life cycle assessment and substance and material flow analysis. Kleijn's expertise extends across various industries, including chemicals, energy, and recycling, where he effectively applies these methodologies to address environmental challenges. He has actively participated in numerous large consortia as part of EU-funded research projects. In recent years, his research has focused on critical raw materials, resilient supply chains, circularity, and material constraints within the evolving landscape of the energy transition.

Wind and solar photovoltaic (PV) power form vital parts of the energy transition toward renewable energy systems. The rapid development of these two renewables represents an enormous infrastructure construction task including both power generation and its associated electrical grid systems, which will generate demand for metal resources. However, most research on material demands has focused on their power generation systems (wind turbines and PV panels), and few have studied the associated electrical grid systems. Here, we estimate the global metal demands for electrical grid systems associated with wind and utility-scale PV power by 2050, using dynamic material flow analysis based on International Energy Agency's energy scenarios and the typical engineering parameters of transmission grids. Results show that the associated electrical grids require large quantities of metals: 27-81 Mt of copper cumulatively, followed by 20-67 Mt of steel and 11-31 Mt of aluminum. Electrical grids built for solar PV have the largest metal demand, followed by offshore and onshore wind. Power cables are the most metal-consuming electrical components compared to substations and transformers. We also discuss the decommissioning issue of electrical grids and their recovery potential. This study would deepen the understanding of the nexus between renewable energy, grid infrastructure, and metal resources.