Raw material risk in clean energy technologies and the power supply system: For which materials should price fluctuations be prioritised?

Abstract

Transformation strategies for climate-friendly energy systems are often obtained with cost-optimising energy system models (ESMs). Although technology cost assumptions considerably affect model outputs, state-of-the-art ESMs generally do not account for the dependence of technology prices on potential raw material price fluctuations. Owing to the large number of raw materials required in central clean energy technologies (CETs), such as photovoltaics, batteries, offshore and onshore wind power, electrolysers, or fuel cells, any future consideration of raw material price fluctuations in ESMs to derive resilient energy system transformation strategies requires prioritising the raw materials considered. We therefore provide a framework for identifying raw materials whose price fluctuations should be explicitly considered in ESM-based energy scenarios. The materials associated with the highest CET-specific risk are determined based on an estimate of the current contributions of selected raw materials to technology costs as well as their geopolitical and market-based supply disruption likelihood (SDL). The analysis is performed both at the level of individual central CETs and at the level of power supply scenarios, which aggregate over several CETs. From the system perspective, the materials with the highest price risk are steel alloy materials (iron, chromium, nickel), rare earth elements (neodymium and dysprosium), lithium, and silicon. High-risk materials at the level of individual CETs can differ.