Direct Te Mining: Resource Availability and Impact on Cumulative Energy Demand of CdTe PV Life Cycles

As the availability of tellurium (Te) is constrained by the production rate of itsmain parent compound (Cu), its potential supply to deploy CdTe photovoltaics (PV) merits investigation. Recently, Te-rich ores and gold-telluride mines have been discovered in several places throughout the world that will allow the economic recovery of Te, independent of the production of copper. In conventional CdTe life-cycle assessments, the environmental impacts of mining and smelting are typically allocated to all the coproducts on the basis of the products' physical amount or economic values. Consequently, directly mining Te from such ores potentially might increase the environmental burden of mining and smelting operations in the life cycle of CdTe PV systems. Other factors influencing the impacts of direct Te mining include the presence of additional coproducts (e.g., gold and silver), the relative contribution of Te to the life-cycle cumulative energy demand (CED) of CdTe PV, the proportion of directly mined Te content relative to the content of the Cu byproduct in the Te-supply chain, and end-of-life CdTe PV recycling. We estimated that the total CED would increase by 1% when 100% of the supply came from direct mining and by 0.7% if we assume a supply mixture representing the ratios of the reserves.