Global supply risk assessment of the metals used in clean energy technologies

Clean energy technologies are emerging as a major contributor to the total energy supply. Some metals play irreplaceable roles in these technologies. The supply risk of metals used in clean energy technologies is gradually increasing. Hence, it is necessary to investigate the supply risks of these metals worldwide. In this study, a comprehensive assessment is conducted to quantify the supply risks of critical metals. The production of the metals is imbalanced worldwide. China, Russia, the United States, Canada, and Australia dominate the supply of these metals. China has the largest supply risk, and the main risk contribution is linked to mining governance and policy, which suggests that strengthening government regulations is necessary. The supply risks in the United States, Russia, and Canada are moderate, and most risks are associated with geologic availability and recycling restrictions. Al, Cu, Fe, Pb and Ag displayed high risks linked to geologic availability and recycling restrictions. Pd, B, Sb, W, Re, Ge and Ga exhibited high risks related to mining governance and policy and environmental sustainability. Difficult exploration processes and highly sensitivity market supplies increased the supply risk. This study provides an important reference for the strategic application of the metals in clean energy technologies in the future.