Circular technology design and its potential influence on minor metals demand in wind and solar expansion

Abstract The rising global demand for metals used in renewable energy generation technologies poses supply risks and socio-environmental impacts, threatening a sustainable energy transition. While the role of circular economy in reducing their demand has gained attention, its potentials related to advances in technology design remains underexplored. Here, we use explorative scenarios to assess circular technology design potentials for 11 minor metals through longer design lifespan, metal intensity reduction, and substitution, during large-scale deployment of wind and solar power in energy transition to 2050. Using Sweden as a case study we show that these strategies collectively may reduce cumulative demands for minor metals by 42–80%, depending on the metal. While all strategies reduce demand for metals in new technologies, their combination slightly increases the gap between this demand and the quantities in decommissioned ones. For wind power, no individual strategy results in metals available for recovery in quantities sufficient to satisfy new demand before 2050, although their combination achieves this for dysprosium and terbium. For solar power, reducing metal intensity alone substantially reduces demand across metals and enables silver and germanium available for recovery to meet new demand before 2050. However, for most metals, the availability for recovery remains insufficient throughout most of the scenario period, highlighting the need for continued additional primary or secondary supply. To fully explore the potential benefits of these circular design strategies, opportunities across all stages of the wind and solar supply chains must be examined—assuming the anticipated technological developments materialize.