Environmental impacts of extreme fast charging

Abstract

As electric vehicles and their associated charging infrastructure continue to evolve, there is potential to simultaneous alleviate range and recharge concerns with the development of extreme fast chargers (XFC) that can fully charge batteries in PEVs in the span of a few minutes. Recent announcements from EVSE providers and vehicle manufacturers suggest that XFC charging stations, which can recharge a BEV at roughly 20 to 25 miles per minute of charging, and XFC-capable BEVs, could be commercially available within the next 5 years. Our study investigates the potential emission impacts of widespread use of extreme fast charging (350 kW) for electric vehicles in 2030. We conduct a novel vehicle charging simulation model by combining empirical charging behavior data across several data sources. These charging demands are then added as exogenous load to the Grid Optimized Operation Dispatch (GOOD) model, which simulates the operation of generators across the Untied States. We find that XFC can increase both greenhouse gas emissions and local air pollutants, though the results are sensitive to local contexts and grid composition.

Health and Climate Impacts from Long-Haul Truck Electrification

“…To address uncertainty in future technology development, we generated and compared 576 counterfactual scenarios that span across diesel truck design (six technology vintages), electric truck design (three scenarios of battery specific energy, two scenarios of battery capacities), truck dispatch (two scenarios), charging power (four scenarios), and electricity grid (two scenarios; SI Table S1). We used the latest available data on long-haul truck flows and current hourly electricity demand . We did not model the endogenous changes in freight flow or electricity load from all other sectors in response to long-haul truck electrification.…”

“…We used the latest available data on long-haul truck flows 41 and current hourly electricity demand. 42 We did not model the endogenous changes in freight flow or electricity load from all other sectors in response to long-haul truck electrification. However, the model presented here is flexible to incorporate future freight flow or electricity demand projections for scenario analysis.…”

“…To accurately characterize truck electrification's full impact on electricity grid operation, we used an economic dispatch model (the GOOD model). 42 The model optimizes the operation of electric generation units (>8000 units across the United States) in an hourly resolution over a year, subject to engineering constraints for all existing and future power plants and major transmission lines. The model divides the contiguous U.S. into 64 regions defined by U.S. EPA's Integrated Planning Model.…”

Private versus Shared, Automated Electric Vehicles for U.S. Personal Mobility: Energy Use, Greenhouse Gas Emissions, Grid Integration, and Cost Impacts

“…We leverage previous work where the authors developed an optimization model that examines SAEVs in the context of temporally varying electricity prices. In this study, we have extended the model to jointly optimize mobility (both SAEVs and private EVs), charging scheduling, and the power sector for the entire U.S. by coupling our previous model to the Grid Operation Optimized Dispatch (GOOD) U.S.-wide electricity model . This combined Grid-integrated Electric Mobility (GEM) model treats the size of the SAEV fleet and the amount of charging infrastructure as continuous decision variables (relaxing the problem from mixed-integer to quadratic), allowing for heterogeneous vehicle ranges and charger levels.…”

“…The transmission between each region has an associated capacity (not always bidirectional) that includes wheeling costs in certain pairwise regions. The dispatch model has been validated against generation and emissions from the power sector in 2018 …”