The transportation sector is undergoing a major transformation. Emerging technologies play indispensable roles in driving this mobility shift, including vehicle electrification, connection, and automation. Among them, wireless power transfer (WPT) technology, or commonly known as wireless charging technology, is in the spotlight in recent years for its applicability in charging electric vehicles (EVs). On one hand, WPT for EVs can solve some of the key challenges in EV development, by: (1) reducing range anxiety of EV owners by allowing “charging while driving”; and (2) downsizing the EV battery while still fulfilling the same trip distance. More en-route wireless charging opportunities result in battery downsizing, which reduces the high EV price and vehicle weight and improves fuel economy. One the other hand, WPT infrastructure deployment is expensive and resource-intensive, and results in significant economic, environmental, and energy burdens, which can offset these benefits.
This research highlights the technology trade-offs and bridges the gap between technology development and deployment by establishing an integrated life cycle assessment and life cycle cost (LCA-LCC) model framework to characterize and evaluate the economic, environmental, and energy performance of WPT EV systems vs. conventional plug-in charging EV systems. Furthermore, life cycle optimization (LCO) techniques are used to improve the life cycle performance of WPT EV fleets.
This study begins with developing LCA-LCC and LCO models to evaluate stationary wireless power transfer (SWPT) for transit bus systems. Based on a case study of Ann Arbor bus systems, the wireless battery can be downsized to 27–44% of a plug-in charged battery, resulting in vehicle lightweighting and fuel economy improvement in the use phase that cancels out the burdens of large-scale infrastructure burdens. Optimal siting strategies of WPT bus charging stations reduced life cycle costs, greenhouse gases (GHG), and energy by up to 13%, 8%, and 8%, respectively, compared to extreme cases of “no charger at any bus stop” and “chargers at every stop”.
Next, the LCA-LCC and LCO model framework is applied to evaluate the economic, energy, and environmental feasibility of dynamic wireless power transfer (DWPT) for charging passenger cars on highways and urban roadways. A case study of Washtenaw County indicates that optimal deployment of DWPT electrifying up to about 3% of total roadway lane-miles reduces life cycle GHG emissions and energy by up to 9.0% and 6.8%, respectively, and enables downsizing of the EV battery capacity by up to 48% compared to the non-DWPT scenarios and boosts EV market penetration to around 50% of all vehicles in 20 years.
Finally, synergies of WPT and autonomous driving technologies in enhancing sustainable mobility are demonstrated using the LCA framework. Compared to a plug-in charging battery electric vehicle system, a wireless charging and shared automated battery electric vehicle (W+SABEV) system will pay back GHG emission burdens of additional infrastructure deployment within 5 years if the wireless charging utility factor is above 19%.
Prof. Greg Keoleian, Chair
Prof. Shelie Miller
Prof. Michael Moore
Prof. Kazu Saitou (ME)
Dr. Tulga Ersal (ME)
Zicheng (Kevin) Bi is a Ph.D. Candidate in the Center for Sustainable Systems at the University of Michigan, Ann Arbor. His research applies life cycle assessment (LCA) models in the nexus of emerging clean vehicle technologies and transportation infrastructure networks. His research examines the roles of the emerging wireless charging technology and connected and automated vehicles in enhancing the sustainability of future electrified mobility. He integrated LCA with optimization models to understand the life cycle energy, emissions, and economic trade-offs of deploying emerging technologies and inform decision-making in urban transportation infrastructure planning. His work provides strategies for OEMs and city planners to deploy the emerging wireless charging technology for electric vehicles with minimized environmental impacts and bridges the gap of traditional engineering research and real-world deployment. He is a recipient of the 3M Prize for Outstanding Achievement in Industrial Ecology. His research is funded by U.S. Department of Energy U.S.-China Clean Energy Research Center Clean Vehicle Consortium and Rackham Pre-Doctoral Fellowship. He earned his M.S. in School for Environment and Sustainability and M.S.E. in Mechanical Engineering at the University of Michigan. He also earned B.E. in Environmental Engineering in Zhejiang University, China. To learn more about his research, please visit: https://scholar.google.com/citations?user=AiVljYEAAAAJ&hl=en