Comparative Analysis of Supply Risk-Mitigation Strategies for Critical Byproduct Minerals: A Case Study of Tellurium

Materials criticality assessment is a screening framework increasingly applied to identify materials of importance that face scarcity risks. Although these assessments highlight materials for the implicit purpose of informing future action, the aggregated nature of their findings make them difficult to use for guidance in developing nuanced mitigation strategy and policy response. As a first step in the selection of mitigation strategies, the present work proposes a modeling framework and accompanying set of metrics to directly compare strategies by measuring effectiveness of risk reduction as a function of the features of projected supply demand balance over time. The work focuses on byproduct materials, whose criticality is particularly important to understand because their supplies are inherently less responsive to market balancing forces, i.e., price feedbacks. Tellurium, a byproduct of copper refining, which is critical to solar photovoltaics, is chosen as a case study, and three commonly discussed byproduct-relevant strategies are selected: dematerialization of end-use product, byproduct yield improvement, and end-of-life recycling rate improvement. Results suggest that dematerialization will be nearly twice as effective at reducing supply risk as the next best option, yield improvement. Finally, due to its infrequent use at present and its dependence upon long product lifespans, recycling end-of-life products is expected to be the least effective option despite potentially offering other benefits (e.g., cost savings and environmental impact reduction)

Portfolio Optimization of Nanomaterial Use in Clean Energy Technologies

While engineered nanomaterials (ENMs) are increasingly incorporated in diverse applications, risks of ENM adoption remain difficult to predict and mitigate proactively. Current decision-making tools do not adequately account for ENM uncertainties including varying functional forms, unique environmental behavior, economic costs, unknown supply and demand, and upstream emissions. The complexity of the ENM system necessitates a novel approach: in this study, the adaptation of an investment portfolio optimization model is demonstrated for optimization of ENM use in renewable energy technologies. Where a traditional investment portfolio optimization model maximizes return on investment through optimal selection of stock, ENM portfolio optimization maximizes the performance of energy technology systems by optimizing selective use of ENMs. Cumulative impacts of multiple ENM material portfolios are evaluated in two case studies: organic photovoltaic cells (OPVs) for renewable energy and lithium-ion batteries (LIBs) for electric vehicles. Results indicate ENM adoption is dependent on overall performance and variance of the material, resource use, environmental impact, and economic trade-offs. From a sustainability perspective, improved clean energy applications can help extend product lifespans, reduce fossil energy consumption, and substitute ENMs for scarce incumbent materials

Challenges in Validation of Sustainable Products and Services in the Green Marketplace

<p>As consumer awareness of sustainability increases, companies are spending more time and money claiming their products or services are more environmentally friendly than other similar products on the market. However, a substantial number of those claims used for advertising and marketing purposes may be misleading or false. While there are organizations that currently provide environmental claim validation services to increase trust in the green marketplace, the challenges in validation of these environmental claims have not been comprehensively examined. This paper explores three major challenges in validating sustainable products and services: 1) the risk of validating erroneous environmental claims, 2) the difficulty of balancing the trade-offs in multi-attribute environmental claim validations, and 3) the challenge of developing protocols for innovative claims within a reasonable time frame. The authors use three real-world examples – evaluation of a longevity claim (and associated reduced environmental impacts) of a product, development of a multi-attribute standard, and construction of test procedures in the absence of an existing standard. Results demonstrate that validations and certifications by dedicated third parties may effectively improve perceptions of trust in greener product claims. These initial findings aim to inform a variety of policy decision-making and potentially help to lay the foundation for establishing rules and regulations for environmental claims in green markets.</p