Regulatory policy governing cadmium-telluride photovoltaics: A case study contrasting life cycle management with the precautionary principle
Introduction
Consistent annual growth in solar power markets coupled with a global shortage in crystalline silicon needed for traditional solar power has propelled the market for thin-film photovoltaics (PV), which is expected to grow from $220 million in 2006 to over $3 billion in 2013 (NanoMarkets, 2006). However, for cadmium-telluride (CdTe) thin-film PV, the market projections are tempered by concern over global environmental policies restricting electronic products containing cadmium, a known human carcinogen (IARC, 1993).
Since earlier this decade, the European Union (EU) has been enacting environmental laws based on the precautionary principle (EU, 2002): a legal doctrine adopted by the United Nations General Assembly that states that when there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used to postpone measures to prevent environmental degradation. The EU has used the precautionary principle to justify increasing use of product stewardship policies that require producers to be financially and legally responsible for the environmental impacts caused by products sold in the EU. The precautionary principle was also the basis for the recently enacted Restriction of Hazardous Substances (RoHS) and Waste of Electrical and Electronic Equipment (WEEE) policies and will influence the evolution of these policies. The main concern with this principle with regard to CdTe PV is that it may eventually result in a complete ban of electronic products containing cadmium as a precaution against cadmium contamination in the environment.
On the other hand, a life cycle management approach to CdTe could be used instead of the precautionary principle. Current manufacturers of CdTe PV obtain cadmium from mining waste that would otherwise be disposed of as hazardous waste, and have adopted end-of-life take back and recycling programs that prevent the release of cadmium to the environment at the end of the product life. This cradle-to-grave management approach to cadmium provides an alternative model with which to regulate CdTe PV.
This study reviews precautionary principle-based regulations on electronics with respect to their potential impact on CdTe PV, and also presents risks of potential environmental cadmium contamination during the product life cycle of a CdTe PV panel, given a life cycle management approach. The aim is to show contrasting approaches to environmental stewardship and their effects on a commercially important technology.
Section snippets
Regulatory policy
International policies governing electronic products containing cadmium have been largely influenced by the EU. The WEEE directive (2002/96/EC) is a generalized policy of the EU that mandates the reduction of the use of natural resources; promotes the reuse, recovery, and recycling of electronic waste; and ensures waste is disposed of safely in order to reduce pollution. The scope of WEEE also states that producers of electronic equipment must provide, at a minimum, the financing for the
Regulatory risks to CdTe PV
The policies described in Section 2, which are based on the precautionary principle, have the potential to encumber the use of CdTe PV for commercial applications. Importantly, CdTe PV is prohibited from being sold in China under existing policy governing cadmium in photoelectric semiconductor devices. Unless PV is included in the expected catalog of exemptions to the Chinese policy, CdTe PV would not be marketable in China. In addition to removing a potentially large market, such a restriction
Life cycle risks
Regulatory approaches based on the precautionary principle represent one way of managing risks of cadmium contamination in the environment from CdTe PV applications. Another approach that is gaining worldwide acceptance is life cycle management, which involves manufacturers assuming product stewardship from beginning to end of product life. Both approaches have the aim of minimizing environmental contamination, but attempt to do so in different ways.
In the life cycle approach, at the beginning
Summary and conclusions
When comparing the precautionary principle approach to regulating CdTe PV with a life cycle management approach, it is necessary to consider all the risks of cadmium contamination in the environment that are present throughout the life cycle of the CdTe PV application. At the beginning of the product life, since cadmium is obtained from mining waste that would otherwise be disposed of as hazardous waste, CdTe PV provides a beneficial use for cadmium, rather than an environmental risk. During
Acknowledgements
We are grateful to Hugh Morrow of the International Cadmium Association for his insight on international policy trends governing cadmium in electronics. We thank the anonymous peer reviewers for their insightful comments that helped improve this paper. We are grateful to O’Brien & Gere for their encouragement of original technical research.
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