Supply-demand balance and resilience

Silicon's supply system is distinct from other materials in this study. The figure below shows that primary supply increases steadily throughout the projection period without peaking or declining, consistent with a material whose availability is not constrained by geological scarcity. However, the figure also shows that there is no real contribution of secondary supply.

From the late 2020s, a persistent supply-demand gap emerges. Demand grows faster than supply throughout the projection period, with the service level (where supply and demand meet) falling below the level required to meet demand intermittently from the early 2030s before remaining below it continuously during the final decade. As a result, unmet demand accumulates progressively rather than appearing as a short-lived disruption, reaching 1.8 million tonnes by 2050. At the same time, desired demand continues to increase, indicating that a growing share of potential demand is never realised because of scarcity and price effects. The model therefore points to a structural imbalance rather than a temporary supply shock.

The key reason this gap emerges despite continued growth in primary production is the near absence of secondary supply. Secondary silicon contributes only negligible volumes throughout the projection period, increasing from around ten thousand tonnes in 2020 to just 70 thousand tonnes by 2050—only a small fraction of primary production. Unlike the other materials examined in this study, silicon continues to derive virtually all of its supply from primary production. As demand increases, every additional tonne must therefore come from new extraction and processing. When primary production cannot expand fast enough, the system has little alternative source of material, causing unmet demand to grow.

Silicon also carries no strategic reserve within the baseline. The trajectory shown is therefore entirely unbuffered: the model captures the underlying behaviour of a system with neither stockpile releases nor meaningful secondary supply available to moderate emerging supply constraints.