Assessing Aspects of Cadmium Supply, Recycling and Environmental Pollution with Respect to Future Photovoltaic Technology Demands and Envionmental Policy Goals

Abstract

Cadmium has appeared as an important element for certain types of solar cells and rechargeable batteries. It is possible that there will be a large increase in demand for technical cadmium in the future. This is in conflict with environmental policies for phasing out cadmium from any technical use worldwide because of its great toxicity to humans. Cadmium toxicity is on par with that of mercury, and data suggests that cadmium exposure has no safe lower limit. There is no shortage of cadmium to extract, and no shortage from lack of cadmium available in the future zinc flow is to be expected. There is a global treaty to ban it from all use. The Integrated Assessment Model WORLD7 was used to assess different aspects of the supply of cadmium to society. It would be possible to produce at least 250,000 tons/year; in reality, the 2023 production is about 24,000 tons/year. The price is about 3500–4500 $/ton and is volatile. Because there is a United Nations agreed global policy to phase out cadmium from all use, demand for cadmium will soon not be met, and there will be an actual shortage of cadmium for any use, including photovoltaic technologies and semiconductors. This is good news for nature, but bad news for the CdTe and CIGS types of photovoltaic panels. It is estimated that only 25% of the planned future capacity may not be available unless good substitutes for cadmium can be found.