Although recent studies of connected and automated vehicles (CAVs) have begun to explore the potential energy and greenhouse gas (GHG) emission impacts from an operational perspective, little is known about how the full life cycle of the vehicle will be impacted. We report the results of a life cycle assessment (LCA) of Level 4 CAV sensing and computing subsystems integrated into internal combustion engine vehicle (ICEV) and battery electric vehicle (BEV) platforms. The results indicate that CAV subsystems could increase vehicle primary energy use and GHG emissions by 3-20% due to increases in power consumption, weight, drag, and data transmission. However, when potential operational effects of CAVs are included (e.g., eco-driving, platooning, and intersection connectivity), the net result is up to a 9% reduction in energy and GHG emissions in the base case. Overall, this study highlights opportunities where CAVs can improve net energy and environmental performance.

h i g h l i g h t sCompared life cycle energy and GHG emissions of wireless to plug-in charging. Modeled a transit bus system to compare both charging methods as a case study. Contrasted tradeoffs of infrastructure burdens with lightweighting benefits. The wireless battery can be downsized to 27-44% of a plug-in charged battery. Explored sensitivity of wireless charging efficiency & grid carbon intensity. g r a p h i c a l a b s t r a c tIn this study, plug-in and wireless charging for an all-electric bus system are compared from the life cycle energy and greenhouse gas (GHG) emissions perspectives. The comparison of life cycle GHG emissions is shown in the graph below. The major differences between the two systems, including the charger, battery and use-phase electricity consumption, are modeled separately and compared aggregately. In the base case, the wireless charging system consumes 0.3% less energy and emits 0.5% less greenhouse gases than plug-in charging system in the total life cycle. To further improve the energy and environmental performance of the wireless charging system, key parameters including grid carbon intensity and wireless charging efficiency are analyzed and discussed in this paper. a b s t r a c tWireless charging, as opposed to plug-in charging, is an alternative charging method for electric vehicles (EVs) with rechargeable batteries and can be applicable to EVs with fixed routes, such as transit buses. This study adds to the current research of EV wireless charging by utilizing the Life Cycle Assessment (LCA) to provide a comprehensive framework for comparing the life cycle energy demand and greenhouse gas emissions associated with a stationary wireless charging all-electric bus system to a plug-in charging all-electric bus system. Life cycle inventory analysis of both plug-in and wireless charging hardware was conducted, and battery downsizing, vehicle lightweighting and use-phase energy consumption http://dx. Plug-in chargingLife cycle assessment Vehicle lightweighting Energy Greenhouse gases were modeled. A bus system in Ann Arbor and Ypsilanti area in Michigan is used as the basis for bus system modeling. Results show that the wirelessly charged battery can be downsized to 27-44% of a plug-in charged battery. The associated reduction of 12-16% in bus weight for the wireless buses can induce a reduction of 5.4-7.0% in battery-to-wheel energy consumption. In the base case, the wireless charging system consumes 0.3% less energy and emits 0.5% less greenhouse gases than the plug-in charging system in the total life cycle. To further improve the energy and environmental performance of a wireless charging electric bus system, it is important to focus on key parameters including carbon intensity of the electric grid and wireless charging efficiency. If the wireless charging efficiency is improved to the same level as the assumed plug-in charging efficiency (90%), the difference of life cycle greenhouse gas emissions between the two systems can increase to 6.3%.

Interest and investment in electric vertical takeoff and landing aircraft (VTOLs), commonly known as flying cars, have grown significantly. However, their sustainability implications are unclear. We report a physics-based analysis of primary energy and greenhouse gas (GHG) emissions of VTOLs vs. ground-based cars. Tilt-rotor/duct/wing VTOLs are efficient when cruising but consume substantial energy for takeoff and climb; hence, their burdens depend critically on trip distance. For our base case, traveling 100 km (point-to-point) with one pilot in a VTOL results in well-to-wing/wheel GHG emissions that are 35% lower but 28% higher than a one-occupant internal combustion engine vehicle (ICEV) and battery electric vehicle (BEV), respectively. Comparing fully loaded VTOLs (three passengers) with ground-based cars with an average occupancy of 1.54, VTOL GHG emissions per passenger-kilometer are 52% lower than ICEVs and 6% lower than BEVs. VTOLs offer fast, predictable transportation and could have a niche role in sustainable mobility.

Electrification and lightweighting technologies are important components of greenhouse gas (GHG) emission reduction strategies for light-duty vehicles. Assessments of GHG emissions from light-duty vehicles should take a cradle-to-grave life cycle perspective and capture important regional effects. We report the first regionally explicit (county-level) life cycle assessment of the use of lightweighting and electrification for light-duty vehicles in the U.S. Regional differences in climate, electric grid burdens, and driving patterns compound to produce significant regional heterogeneity in the GHG benefits of electrification. We show that lightweighting further accentuates these regional differences. In fact, for the midsized cars considered in our analysis, model results suggest that aluminum lightweight vehicles with a combustion engine would have similar emissions to hybrid electric vehicles (HEVs) in about 25% of the counties in the US and lower than battery electric vehicles (BEVs) in 20% of counties. The results highlight the need for a portfolio of fuel efficient offerings to recognize the heterogeneity of regional climate, electric grid burdens, and driving patterns.

Substituting conventional materials with lightweight materials is an effective way to reduce the life cycle greenhouse gas (GHG) emissions from light-duty vehicles. However, estimated GHG emission reductions of lightweighting depend on multiple factors including the vehicle powertrain technology and efficiency, lightweight material employed, and end-of-life material recovery. We developed a fleet-based life cycle model to estimate the GHG emission changes due to lightweighting the U.S. light-duty fleet from 2016 to 2050, using either high strength steel or aluminum as the lightweight material. Our model estimates that implementation of an aggressive lightweighting scenario using aluminum reduces 2016 through 2050 cumulative life cycle GHG emissions from the fleet by 2.9 Gt CO 2 eq (5.6%), and annual emissions in 2050 by 11%. Lightweighting has the greatest GHG emission reduction potential when implemented in the near-term, with two times more reduction per kilometer traveled if implemented in 2016 rather than in 2030. Delaying implementation by 15 years sacrifices 72% (2.1 Gt CO 2 eq) of the cumulative GHG emission mitigation potential through 2050. Lightweighting is an effective solution that could provide important near-term GHG emission reductions especially during the next 10−20 years when the fleet is dominated by conventional powertrain vehicles.