New from CSS: 10 Green Principles for Vehicle Lightweighting

Originally published: 
April, 2019

Researchers in the Center for Sustainable Systems and collaborators across U-M and two national labs recently developed a set of principles based on a lifecycle framework to guide vehicle lightweighting.

Development of the principles was inspired by the existing body of research on the environmental impacts of transportation vehicles. Prior studies have found that the bulk of the impacts over a vehicle’s life cycle occur in the use phase. However, measures intended to reduce use-phase environmental burdens (like lightweighting) often result in higher burdens in other phases, such as the manufacturing phase. The green principles developed by the research team address this challenge, and were recently published in Environmental Science and Technology

Principles like these—based on lifecycle assessment concepts, data, methods, and applied experience—are intended to guide practitioners through the environmental improvement process. Similar sets of principles have been developed in several fields, including chemistry, engineering, and design. This is the first set of green principles related to vehicle lightweighting.

“The production and use of products in today’s global economy typically involve a number of companies in the supply chain crossing several industrial sectors,” said Alan Taub, professor in U-M College of Engineering and one of the study’s coauthors. “The Green Principles will provide a framework for aligning the interests of all parties along common guidelines.”

“We intend these principles to provide useful guidance to a wide range of stakeholders, including manufacturers, suppliers, and policy-makers, as they evaluate the tradeoffs inherent in improving the environmental performance of complex vehicle systems” said Geoff Lewis, Research Scientist in the Center for Sustainable Systems and the study’s first author.

10 Green Principles for Vehicle Lightweighting

  1. Resolve Trade-Offs between Technical, Economic, and Environmental Performance
    Successful and high-impact lightweighting strategies must resolve trade-offs between technical, economic, and environmental performance while maintaining safety standards.
  2. Source Abundant and Low-Environmental-Impact Materials
    Choose to use materials that are abundant and use lower-impact material production energy sources.
  3. Use Secondary Materials
    Secondary materials may reduce demand for virgin materials and can result in lower material production impacts (e.g., energy, GHG emissions).
  4. Maximize Efficiency in Manufacturing for Lightweight Technologies
    Develop and select environmentally preferable manufacturing technologies that have high material yields and match target production volumes.
  5. Do Not Overdesign
    Evaluate the potential increase in production burdens of strategies to extend service life and durability against fuel savings in the use phase. Also, design for reasonable part lifetimes and use optimal replacement strategies to reduce environmental impacts.
  6. Design for Maximum Material Recovery
    Select lightweight materials that are recoverable through existing and planned end-of-life infrastructure and do not impede recoverability of other materials. Seek to use materials that have the maximum potential to reduce demand for primary materials upon recovery and minimize downcycling.
  7. Evaluate Trade-Offs between Life Cycle Phases
    To ensure reduction in overall life cycle impacts, use lifecycle assessment to quantify changes across life cycle phases and between impact categories because of lightweighting.
  8. Develop Lightweighting Applications To Maximize Benefits
    Prioritize lightweighting applications that achieve the greatest environmental benefit. Powertrain, mode, fleet distribution of vehicle types and use-phase energy mix in the deployment market all influence environmental benefit.
  9. Identify Broader System Opportunities
    Evaluate additional benefits resulting from component and vehicle lightweighting, including secondary mass savings and resized and alternative powertrains. Identify and characterize system-level benefits and costs of lighter vehicles (e.g., transportation infrastructure, vehicle miles traveled rebound effect) to provide guidance toward enhanced environmental sustainability.
  10. Develop and Implement Policies To Advance Life Cycle Environmental Performance
    Implement holistic policies that support the adoption of materials, technologies, and strategies that lead to better environmental outcomes and avoid shifting burden across life cycle phases.

The research undergirding the 10 Green Principles for Lightweighting was led by the Center for Sustainable Systems (CSS). CSS is part of the School for Environment and Sustainability at the University of Michigan. It is an evolution of the national Pollution Prevention Center for Higher Education, which was created in 1991 by a U.S. EPA competitive grant to collect, develop, and disseminate educational materials on pollution prevention. Today, CSS creates systems analysis methods, models, and metrics for advancing sustainable futures, and collaborates with diverse stakeholders to catalyze the transformation of systems to enhance sustainability. Research is the center’s primary activity, with education and outreach continuing as key goals.

The study was sponsored by Lightweighting Innovations for Tomorrow (LIFT). LIFT is a public-private partnership that develops and deploys advanced lightweight materials manufacturing technologies for defense and commercial applications, and implements education and training programs to prepare the advanced manufacturing workforce for jobs in the application of innovative lightweight metal production and component/subsystem manufacturing technologies. It was established in 2014 following a competitive process led by the U.S. Department of Defense. The winning proposal team, American Lightweight Materials Manufacturing Innovation Institute (ALMMII) is a non-profit organization founded by Ohio-based manufacturing technology non-profit EWI, the University of Michigan, and The Ohio State University. The LIFT consortium headquartered in Detroit, is regional in nature, but serves the entire nation by involving more than 200 companies, universities, non-profit research institutions, and workforce development intermediaries from around the country.