Charging Strategies to Minimize Greenhouse Gas Emissions of Electrified Delivery Vehicles

A multi-scale lifecycle and technoeconomic framework for higher education fleet electrification

Transportation accounts for one-quarter of all energy related greenhouse gas emissions. As it pertains to transport electrification, higher education institutions-such as universities-can model solutions that affect broader society. Despite this, higher education's role in fleet electrification adoption has been understudied. We, therefore, modeled an archetypical higher education institution to analyze the carbon and economic payback periods of three electrification scenarios (Business-as-Usual, Targeted Electrification, and Full Electrification) using a cradle-to-grave lifecycle and technoeconomic approach. Given the archetypical higher education institution fleet of 368 vehicles, results show an economic ratio plateau point of about 8 years at 20 fuel-based cars replaced by electric vehicles and a carbon payback period peak of roughly 10 months at 50 fuel-based cars replaced. We then performed a multi-scalar analysis by leveraging implementation theory. We find that higher education institutions that adhere to the tenets of implementation theory are poised to be pro-environmental change agents in many regions and countries. The methods and findings herein can be adapted to other institutions, regardless of fleet size, and can bolster relevant decision-making outcomes now.

Multisectoral drivers of decarbonizing battery electric vehicles in China

China has made great progress in the electrification of passenger cars, and the sales of battery electric vehicles (BEVs) have exceeded 10%. We applied a life-cycle assessment (LCA) method to estimate the carbon dioxide (CO₂) emissions of the past (2015), present (2020), and future (2030) BEVs, incorporating China's carbon peaking and neutrality policies, which would substantially reduce emissions from the electricity, operation efficiency, metallurgy, and battery manufacturing industries. BEVs can reduce cradle-to-grave (C2G) CO₂ emissions by ∼40% compared with internal combustion engine vehicles (ICEVs) on the national-average level in 2020, far more significant than the benefit in 2015. Improved BEV operating efficiency was the largest factor driving emission reductions from 2015 to 2020. Looking forward to 2030, China's BEVs equipped with nickel-cobalt-manganese (NCM) batteries can achieve a further 43% of CO₂ emissions reductions, among which 51 g km^-1 of reduction is from the well-to-wheels (WTW) stage majorly owing to the further cleaner electricity mix, while other vehicle-cycle benefits are mainly from the advancement of battery (12 g km^-1) and related metal materials (5 g km^-1). We highlight the importance of better material efficiency and synchronized decarbonization through the automotive industrial chain in promoting climate mitigation from transport activities.

Life Cycle Greenhouse Gas Emissions of the USPS Next-Generation Delivery Vehicle Fleet

The United States Postal Service (USPS) plans to purchase 165,000 next-generation delivery vehicles (NGDVs) between 2023 and 2032. The USPS submitted an environmental impact statement (EIS) for two NGDV procurement scenarios: (1) 90% internal combustion engine vehicles (ICEVs) and 10% battery electric vehicles (BEVs) ("ICEV scenario") and (2) 100% BEVs ("BEV scenario"). To correct several significant deficiencies in the EIS, we conduct a cradle-to-grave life cycle greenhouse gas (GHG) assessment of these two scenarios. Our analysis improves upon the USPS's EIS by including vehicle production and end-of-life emissions, future grid decarbonization, and more accurate vehicle operating emissions. In our base case, we find that the ICEV and BEV scenarios would result in 15% greater and 8% fewer GHG emissions, respectively, than the USPS estimate. Favorable vehicle and grid development would result in 63% lower BEV scenario emissions than the USPS estimate. Consequently, we calculate a cumulative lifetime emission reduction of 57-82% (14.7-21.4 Mt CO₂e) from procuring 100% BEVs instead of 10% BEVs, compared to the USPS's estimate of 10.3 Mt. Given the long NGDV lifetimes, committing to the ICEV scenario squanders an ideal use case for BEVs, jeopardizes meeting our climate goals, and forgoes potential climate and environmental justice co-benefits.

Energy, Emissions, and Cost Impacts of Charging Price Strategies for Electric Vehicles

While utilizing price signals to affect charging behaviors has been identified as a promising strategy to manage charging loads, few studies discuss their impacts comprehensively. We investigate how different charging price strategies can affect the spatial and temporal distribution of charging activities at the individual level and the required charging infrastructure system. We utilize an integrated optimization platform for electric vehicle (EV) charging management and infrastructure placement in home and nonhome locations in San Diego, CA, that include charging price strategies, infrastructure costs, and mobility demand patterns. We evaluate three pricing scenarios and demonstrate that the time-of-use pricing scheme results in the highest emissions and the real-time one the lowest, which are 20.2% higher and 0.7% lower than the annual emissions under the flat rate scenario, which is about 8,787 MtCO₂e. Our results show that the charging load profile is the result of various determinants including the dynamic electricity price, price elasticity of charging demand, travel and dwelling constraints, carbon price, as well as exclusive home and shared nonhome charging patterns. The effectiveness of changing charging behavior through internalizing climate damage to obtain environmental benefits depends largely on charging price strategies, implying that policymakers should consider charging price strategies in conjunction with carbon pricing rather than independently.