Byproduct critical metal supply and demand and implications for the energy transition: A case study of tellurium supply and CdTe PV demand

The transition towards low-emission energy generation, storage and transport will require metal production beyond the already historically high production levels the minerals industry is achieving. This is problematic for several reasons, one being the fact that a majority of the metals required for these technologies are considered critical and are currently supplied as low volume byproducts of other main commodities, such as Cu or Zn. The low volume and specialist nature of these byproduct metals means that economic drivers to optimize their re-covery are absent, causing these important resources to be lost to mine waste. Thin-film cadmium-telluride (CdTe) photovoltaics continue to be an emerging energy technology alternative to Si-based solar panels. How-ever, the Cd and Te used to manufacture these panels are almost exclusively sourced as byproducts of either Zn or Cu. This study presents new Te supply and demand scenarios for CdTe photovoltaics based on a new Te material intensity value of 15.2 Mg/GW, outlining potential variations in demand as a result of the energy transition. We also examine how market demand and downstream low-emissions energy generation can be used to drive improved byproduct critical metal recovery from the Cu sector. This improved recovery of byproduct critical metals could ultimately lead toward the more responsible use of finite non-renewable resources as well as providing increased amounts of the raw materials for the power generation infrastructure required by the energy transition.

Automated summary

The transition to low-emission energy generation, storage, and transport requires increased metal production. However, most of the metals needed for these technologies are considered critical and are currently supplied as low volume byproducts. Thin-film cadmium-telluride photovoltaics are a promising alternative to silicon-based solar panels. This study presents new scenarios for tellurium supply and demand and explores how improved byproduct critical metal recovery can be driven by market demand and low-emission energy generation.